Islamabad: Even as Pakistan continues to import pharmaceutical raw material and finished medicines from India despite the sharp military and diplomatic tensions witnessed in May this year, a widely used hypertension drug that was readily available until recently has quietly vanished from the market after an Indian supplier refused to provide its key raw material to a Pakistani manufacturer, industry and regulatory officials say.
The medicine is Calan and Calan SR, branded forms of verapamil hydrochloride, a decades-old but still essential drug used to treat high blood pressure, certain heart rhythm disorders and angina. Until a few months ago, the medicine was routinely available in pharmacies.
Its sudden disappearance has raised questions among doctors and patients, particularly because there is no formal ban on importing Active Pharmaceutical Ingredients or finished therapeutic goods from India.
Pharmaceutical industry officials say the shortage is not the result of any government restriction. Instead, it stems from the refusal of a specific Indian API supplier to continue supplying verapamil raw material to a Pakistani manufacturer. This, they say, stands in contrast to the broader trade reality, where multiple Indian suppliers are still sending APIs, vaccines and even finished medicines to Pakistan.
“There is no policy level ban. Raw material is coming in from India, finished formulations are coming in, and vaccines are also being imported,” said a senior industry official. “But in this particular case, the Indian supplier of verapamil API has simply declined to supply Pakistan, despite demand and past business.”
Verapamil is part of the calcium channel blocker group of medicines. It works by relaxing blood vessels and slowing electrical signals in the heart, reducing blood pressure and helping control abnormal heart rhythms. Cardiologists say that while many patients with hypertension can be managed on newer drugs, some respond uniquely well to verapamil and struggle when switched to alternatives.
“There are patients whose blood pressure remains controlled only on verapamil,” said Dr. Khurram Nawaz, a cardiologist at a tertiary care hospital. “When you change their medicine, they may develop unstable readings, palpitations or side effects. That is why its sudden absence is being felt more sharply than people realise.”
Industry sources say the manufacturer of Calan and Calan SR has now approached Chinese suppliers to secure an alternative source of verapamil API. However, they stress that the medicine cannot immediately return to the market because changing the source of an API requires mandatory stability studies and regulatory clearance.
“When you change an API source, you have to prove that the finished product remains stable, safe and effective over its entire shelf life,” explained a regulatory expert. “Differences in impurity profiles, crystal structure or manufacturing processes can affect how the drug behaves. Stability studies are not a formality, they are essential for patient safety.”
Officials at the Drug Regulatory Authority of Pakistan confirmed that pharmaceutical imports from India are continuing uninterrupted. They said both APIs and finished therapeutic goods, including vaccines, are still entering Pakistan through normal channels.
“Pakistani companies are currently importing tetanus toxoid and bulk material for the local production of hepatitis B vaccine from India,” a DRAP official said. “There is no restriction on these imports, and supply chains remain active.”
At the same time, DRAP officials acknowledged that the verapamil shortage exposes Pakistan’s dependence on a narrow range of foreign suppliers. Some regulators view the episode as a warning rather than an anomaly.
“This situation shows why over-reliance on a single country or supplier is risky,” said an official. “It is actually better in the long run that we diversify our sources. But shifting dependence away from India will take time, investment and careful regulatory oversight.”
Industry representatives agree but warn that patients bear the immediate cost of such disruptions. They are urging regulators to expedite the review of alternative API sources so that locally manufactured verapamil can return to the market without compromising quality.
Until then, doctors say patients are being managed on substitute medicines, often with mixed results. The disappearance of a once-available hypertension drug, despite ongoing imports from India during a period of near-war, underscores how fragile medicine supply chains can be and how quickly political or commercial decisions can translate into real consequences for patients.