<?xml version="1.0" encoding="US-ASCII" standalone="no"?>
<!--Generated by ThunderDome XBRL - 04:11PM UTC 2025-05-13--><link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-note-e-debt-obligations-future-minimum-principal-payments-details" xlink:href="zvra-20250331.xsd#statement-note-e-debt-obligations-future-minimum-principal-payments-details" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-note-e-debt-obligations-future-minimum-principal-payments-details" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear" xlink:type="locator"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:type="arc"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-unaudited-condensed-consolidated-balance-sheets-" xlink:href="zvra-20250331.xsd#statement-unaudited-condensed-consolidated-balance-sheets-" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-unaudited-condensed-consolidated-balance-sheets-" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsAndOtherReceivablesNetCurrent" xlink:label="us-gaap_AccountsAndOtherReceivablesNetCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedIncomeTaxesNoncurrent" xlink:label="us-gaap_AccruedIncomeTaxesNoncurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryNet" xlink:label="us-gaap_InventoryNet" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryNoncurrent" xlink:label="us-gaap_InventoryNoncurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="us-gaap_LongTermDebtNoncurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockValue" xlink:label="us-gaap_TreasuryStockValue" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_DerivativeAndWarrantLiabilityNoncurrent" xlink:label="zvra_DerivativeAndWarrantLiabilityNoncurrent" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_DiscountAndRebateLiabilitiesCurrent" xlink:label="zvra_DiscountAndRebateLiabilitiesCurrent" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_DiscountAndRebateLiabilitiesNoncurrent" xlink:label="zvra_DiscountAndRebateLiabilitiesNoncurrent" xlink:type="locator"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AccountsAndOtherReceivablesNetCurrent" xlink:type="arc"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_InventoryNet" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Goodwill" xlink:type="arc"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_AssetsCurrent" xlink:type="arc"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_OtherAssetsNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_InventoryNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="zvra_DiscountAndRebateLiabilitiesCurrent" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_OtherLiabilitiesNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="zvra_DiscountAndRebateLiabilitiesNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_LiabilitiesCurrent" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="zvra_DerivativeAndWarrantLiabilityNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_LongTermDebtNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_AccruedIncomeTaxesNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="arc"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_TreasuryStockValue" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_CommonStockValue" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="arc"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_PreferredStockValue" xlink:type="arc"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_StockholdersEquity" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_Liabilities" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-unaudited-condensed-consolidated-statements-of-cash-flows" xlink:href="zvra-20250331.xsd#statement-unaudited-condensed-consolidated-statements-of-cash-flows" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-unaudited-condensed-consolidated-statements-of-cash-flows" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:label="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables" xlink:label="us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="us-gaap_IncreaseDecreaseInInventories" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities" xlink:label="us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaidInKindInterest" xlink:label="us-gaap_PaidInKindInterest" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireOtherInvestments" xlink:label="us-gaap_PaymentsToAcquireOtherInvestments" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments" xlink:label="us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_ConsultingFeesPaidInStock" xlink:label="zvra_ConsultingFeesPaidInStock" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_FairValueAdjustmentOfInvestments" xlink:label="zvra_FairValueAdjustmentOfInvestments" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_FairValueAdjustmentOfWarrantsAndCvrLiability" xlink:label="zvra_FairValueAdjustmentOfWarrantsAndCvrLiability" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_IncomeTaxExpenseBenefitNoncashAdjustment" xlink:label="zvra_IncomeTaxExpenseBenefitNoncashAdjustment" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_IncreaseDecreaseInDiscountAndRebateLiabilities" xlink:label="zvra_IncreaseDecreaseInDiscountAndRebateLiabilities" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_IncreaseDecreaseInOperatingLeaseRightofuseAsset" xlink:label="zvra_IncreaseDecreaseInOperatingLeaseRightofuseAsset" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_PaymentsOfPrincipalOnInsuranceFinancingArrangements" xlink:label="zvra_PaymentsOfPrincipalOnInsuranceFinancingArrangements" xlink:type="locator"/>
    <link:calculationArc order="0" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables" xlink:type="arc"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:type="arc"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInInventories" xlink:type="arc"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:type="arc"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:type="arc"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="zvra_FairValueAdjustmentOfWarrantsAndCvrLiability" xlink:type="arc"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="zvra_ConsultingFeesPaidInStock" xlink:type="arc"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="zvra_FairValueAdjustmentOfInvestments" xlink:type="arc"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="zvra_IncomeTaxExpenseBenefitNoncashAdjustment" xlink:type="arc"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_ShareBasedCompensation" xlink:type="arc"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities" xlink:type="arc"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_PaidInKindInterest" xlink:type="arc"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_DepreciationDepletionAndAmortization" xlink:type="arc"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:type="arc"/>
    <link:calculationArc order="14" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="zvra_IncreaseDecreaseInOperatingLeaseRightofuseAsset" xlink:type="arc"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:type="arc"/>
    <link:calculationArc order="16" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetIncomeLoss" xlink:type="arc"/>
    <link:calculationArc order="17" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="zvra_IncreaseDecreaseInDiscountAndRebateLiabilities" xlink:type="arc"/>
    <link:calculationArc order="0" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments" xlink:type="arc"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquireOtherInvestments" xlink:type="arc"/>
    <link:calculationArc order="0" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="zvra_PaymentsOfPrincipalOnInsuranceFinancingArrangements" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_ProceedsFromStockOptionsExercised" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-unaudited-condensed-consolidated-statements-of-operations" xlink:href="zvra-20250331.xsd#statement-unaudited-condensed-consolidated-statements-of-operations" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-unaudited-condensed-consolidated-statements-of-operations" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization" xlink:label="us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSoldAmortization" xlink:label="us-gaap_CostOfGoodsAndServicesSoldAmortization" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpenses" xlink:label="us-gaap_CostsAndExpenses" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating" xlink:label="us-gaap_InterestExpenseNonoperating" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost" xlink:label="us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_FairValueAdjustmentOfInvestments" xlink:label="zvra_FairValueAdjustmentOfInvestments" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_FairValueAdjustmentOfWarrantsAndCvrLiability" xlink:label="zvra_FairValueAdjustmentOfWarrantsAndCvrLiability" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_InterestAndOtherIncomeExpenseNet" xlink:label="zvra_InterestAndOtherIncomeExpenseNet" xlink:type="locator"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CostsAndExpenses" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CostsAndExpenses" xlink:to="us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost" xlink:type="arc"/>
    <link:calculationArc order="0" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization" xlink:type="arc"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_CostOfGoodsAndServicesSoldAmortization" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:type="arc"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_CostsAndExpenses" xlink:type="arc"/>
    <link:calculationArc order="0" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="zvra_FairValueAdjustmentOfWarrantsAndCvrLiability" xlink:type="arc"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_InterestExpenseNonoperating" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="zvra_InterestAndOtherIncomeExpenseNet" xlink:type="arc"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="zvra_FairValueAdjustmentOfInvestments" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_NonoperatingIncomeExpense" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_OperatingIncomeLoss" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:type="arc"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeTaxExpenseBenefit" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-unaudited-condensed-consolidated-statements-of-comprehensive-loss" xlink:href="zvra-20250331.xsd#statement-unaudited-condensed-consolidated-statements-of-comprehensive-loss" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-unaudited-condensed-consolidated-statements-of-comprehensive-loss" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:type="locator"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:to="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-note-d-inventories-summary-of-inventory-details" xlink:href="zvra-20250331.xsd#statement-note-d-inventories-summary-of-inventory-details" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-note-d-inventories-summary-of-inventory-details" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryFinishedGoods" xlink:label="us-gaap_InventoryFinishedGoods" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryRawMaterials" xlink:label="us-gaap_InventoryRawMaterials" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryWorkInProcess" xlink:label="us-gaap_InventoryWorkInProcess" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_InventoryCurrentAndNoncurrentTotal" xlink:label="zvra_InventoryCurrentAndNoncurrentTotal" xlink:type="locator"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="zvra_InventoryCurrentAndNoncurrentTotal" xlink:to="us-gaap_InventoryFinishedGoods" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="zvra_InventoryCurrentAndNoncurrentTotal" xlink:to="us-gaap_InventoryWorkInProcess" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="zvra_InventoryCurrentAndNoncurrentTotal" xlink:to="us-gaap_InventoryRawMaterials" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-note-e-debt-obligations-aggregate-principal-amount-details" xlink:href="zvra-20250331.xsd#statement-note-e-debt-obligations-aggregate-principal-amount-details" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-note-e-debt-obligations-aggregate-principal-amount-details" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="us-gaap_DeferredFinanceCostsNet" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayable" xlink:label="us-gaap_NotesPayable" xlink:type="locator"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NotesPayable" xlink:to="us-gaap_DebtInstrumentCarryingAmount" xlink:type="arc"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NotesPayable" xlink:to="us-gaap_DeferredFinanceCostsNet" xlink:type="arc"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NotesPayable" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-note-k-leases-maturities-of-lease-liabilities-details" xlink:href="zvra-20250331.xsd#statement-note-k-leases-maturities-of-lease-liabilities-details" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-note-k-leases-maturities-of-lease-liabilities-details" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour" xlink:label="zvra_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour" xlink:type="locator"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="arc"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="arc"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="zvra_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-note-k-leases-lease-cost-details" xlink:href="zvra-20250331.xsd#statement-note-k-leases-lease-cost-details" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-note-k-leases-lease-cost-details" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost" xlink:label="us-gaap_LeaseCost" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost" xlink:label="us-gaap_OperatingLeaseCost" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermLeaseCost" xlink:label="us-gaap_ShortTermLeaseCost" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubleaseIncome" xlink:label="us-gaap_SubleaseIncome" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableLeaseCost" xlink:label="us-gaap_VariableLeaseCost" xlink:type="locator"/>
    <link:loc xlink:href="zvra-20250331.xsd#zvra_FinanceLeaseCostTotal" xlink:label="zvra_FinanceLeaseCostTotal" xlink:type="locator"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="zvra_FinanceLeaseCostTotal" xlink:to="us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:type="arc"/>
    <link:calculationArc order="0" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LeaseCost" xlink:to="us-gaap_SubleaseIncome" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LeaseCost" xlink:to="us-gaap_OperatingLeaseCost" xlink:type="arc"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LeaseCost" xlink:to="zvra_FinanceLeaseCostTotal" xlink:type="arc"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LeaseCost" xlink:to="us-gaap_VariableLeaseCost" xlink:type="arc"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LeaseCost" xlink:to="us-gaap_ShortTermLeaseCost" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.kempharm.com/20250331/role/statement-note-k-leases-supplement-balance-sheet-information-related-to-lease-details" xlink:href="zvra-20250331.xsd#statement-note-k-leases-supplement-balance-sheet-information-related-to-lease-details" xlink:type="simple"/>
  <link:calculationLink xlink:role="http://www.kempharm.com/20250331/role/statement-note-k-leases-supplement-balance-sheet-information-related-to-lease-details" xlink:type="extended">
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="locator"/>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="locator"/>
    <link:calculationArc order="0" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_FinanceLeaseRightOfUseAsset" xlink:to="us-gaap_FinanceLeaseRightOfUseAssetAccumulatedAmortization" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_FinanceLeaseRightOfUseAsset" xlink:to="us-gaap_FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization" xlink:type="arc"/>
    <link:calculationArc order="0" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="arc"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
