What to do if Singulair is in shortage — for Japan
Drug shortages happen periodically — manufacturing issues, supply chain disruptions, regulatory holds — and Singulair (Montelukast) may become temporarily unavailable in some pharmacies or countries. For chronic users at 4mg, 5mg, 10mg, 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 Singulair, shortage of one strength or one manufacturer rarely means total unavailability of Montelukast — authorised generics or alternative manufacturers usually fill the gap, with the pharmacist coordinating substitution and the prescriber confirming any formulation change at 4mg, 5mg, 10mg.
- Regulator
- PMDA (Pharmaceuticals and Medical Devices Agency)
- Currency
- JPY
How shortages work for Singulair
When Singulair is in shortage, the pharmacist usually has several options: dispense an authorised generic of Montelukast, 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 Respiratory Medications agent. Montelukast selectively blocks the CysLT1 receptor, which mediates the action of leukotrienes C4, D4 and E4 — proinflammatory mediators released by mast cells and eosinophils.
Practical steps
According to general pharmacy practice, the first step in a Singulair shortage is to ask the pharmacist about authorised generic availability — most shortages affect a single brand or strength, not the entire supply of Montelukast at 4mg, 5mg, 10mg. 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 Singulair? ▾
Ask the pharmacist whether an authorised generic of Montelukast is available — usually yes — or whether another pharmacy in the area has stock of Singulair at 4mg, 5mg, 10mg. The pharmacist can also contact the prescriber if a formulation switch is needed.
Will Singulair 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 Montelukast is the standard alternative and is clinically equivalent to Singulair at the same 4mg, 5mg, 10mg strength.
What to do if Singulair 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.