What to do if Acyclovir is in shortage — for Japan
Drug shortages happen periodically — manufacturing issues, supply chain disruptions, regulatory holds — and Acyclovir (Acyclovir) may become temporarily unavailable in some pharmacies or countries. For chronic users at 200mg, 400mg, 800mg, knowing how to handle a shortage prevents unnecessary treatment interruption.
Japan context
Drug shortages in Japan are tracked by PMDA (Pharmaceuticals and Medical Devices Agency) when significant. For Acyclovir, shortage of one strength or one manufacturer rarely means total unavailability of Acyclovir — authorised generics or alternative manufacturers usually fill the gap, with the pharmacist coordinating substitution and the prescriber confirming any formulation change at 200mg, 400mg, 800mg.
- Regulator
- PMDA (Pharmaceuticals and Medical Devices Agency)
- Currency
- JPY
How shortages work for Acyclovir
When Acyclovir is in shortage, the pharmacist usually has several options: dispense an authorised generic of Acyclovir, source from a different manufacturer of the same active ingredient, suggest a different formulation (e.g. liquid, dispersible) or, in extended shortages, ask the prescriber to consider an alternative Antiviral Medications agent. Acyclovir is a guanosine analogue selectively phosphorylated by viral thymidine kinase to its monophosphate form, then by cellular kinases to acyclovir triphosphate.
Practical steps
According to general pharmacy practice, the first step in a Acyclovir shortage is to ask the pharmacist about authorised generic availability — most shortages affect a single brand or strength, not the entire supply of Acyclovir at 200mg, 400mg, 800mg. The prescriber should be informed if the pharmacist needs to substitute or change formulation. Stockpiling or buying extra outside regulated channels is not the right response.
Frequently asked questions
What do I do if my pharmacy doesn't have Acyclovir? ▾
Ask the pharmacist whether an authorised generic of Acyclovir is available — usually yes — or whether another pharmacy in the area has stock of Acyclovir at 200mg, 400mg, 800mg. The pharmacist can also contact the prescriber if a formulation switch is needed.
Will Acyclovir come back in stock? ▾
Most shortages are resolved within weeks to months as manufacturing or supply issues are fixed. Until then, the authorised generic of Acyclovir is the standard alternative and is clinically equivalent to Acyclovir at the same 200mg, 400mg, 800mg strength.
What to do if Acyclovir is in shortage in other countries
- the United StatesFDA (Food and Drug Administration)
- the United KingdomMHRA (Medicines and Healthcare products Regulatory Agency)
- SpainAEMPS (Agencia Española de Medicamentos y Productos Sanitarios)
- MexicoCOFEPRIS (Comisión Federal para la Protección contra Riesgos Sanitarios)
- ArgentinaANMAT (Administración Nacional de Medicamentos, Alimentos y Tecnología Médica)
- GermanyBfArM (Bundesinstitut für Arzneimittel und Medizinprodukte)
- FranceANSM (Agence nationale de sécurité du médicament et des produits de santé)
- ItalyAIFA (Agenzia Italiana del Farmaco)
- BrazilANVISA (Agência Nacional de Vigilância Sanitária)
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.