The NHS has extended the Serious Shortage Protocol (SSP) for blood pressure medication Ramipril 1.25 mg to 30 October.
It was first issued on 22 April and was to end on 24 July.
Olivier Picard, Chair of the National Pharmacy Association (NPA), said: "We are concerned by this ongoing shortage, which is one of many shortages of medicines that pharmacies and their patients have had to grapple with in recent years.
"Millions of patients rely on Ramipril, and although there are alternative medicines available, supplies of these must be managed carefully by the government to ensure subsequent demand can be met.
"The government should allow pharmacists to make appropriate substitutions to Ramipril prescriptions to ensure patients do not have to go back to their GP to find an alternative.
"Pharmacies are increasingly facing supply problems affecting everyday medicines on which millions rely every day, with some describing shortages as the worst they have ever experienced.
"While the medicine supply chain is complex, the rising problem of shortages across a wide range of medication is extremely worrying for patients and heartbreaking for pharmacists who go to great lengths to ensure they don't turn them away.
"Fragility in the global supply chain is worsened by international instability and this new government must convene an urgent taskforce to fully grip this chronic problem."
