The war in Iran has pushed up the price of widely used medicines in England, including painkillers and hay fever medication, leading pharmacists have warned.

Community chemists are charging customers 20-30% more for paracetamol than they did in February, according to the National Pharmacy Association (NPA), and many have run out of certain strengths of aspirin and co-codamol.

Over-the-counter prices for cetirizine tablets, a common hay fever medication, are also estimated to have risen 20-30% in the same period.

The jump in petrol and diesel prices since the war began nearly eight weeks ago has increased manufacturing and transport costs for medicine suppliers. These have fed through to pharmacies, which are paying 40-50% more to order in stock.

The conflict has also doubled air freight costs – one in five NHS medicines comes in by air – and strangled supplies of petroleum derivatives from the Gulf, which are used to make many common medications, including paracetamol, aspirin and co-codamol.

Manufacturers of generic off-patent drugs operating on low margins have started to increase their prices, which is driving up the NHS medicines bill as well as prices at the pharmacy till.

Some pharmacies have stopped selling aspirin over the counter, in part due to supply constraints that started before the Iran war. Temporary shortages of medicines are common, but could become more serious if the strait of Hormuz, a key shipping route for petrochemicals, does not reopen soon.

Olivier Picard, chair of the NPA, which represents 6,000 community pharmacies in England, said that on 27 March his chemist in Berkshire had been unable to order paracetamol. When it became available again a few days later “the [wholesale] price had doubled”.

While suppliers have long-term pricing agreements with NHS hospitals, they have more leeway over drugs provided to pharmacies and GP practices.

Picard said the price he pays wholesalers for a pack of 100 500mg paracetamol tablets had jumped from 41p to £1.99 by the end of March, but has since eased back to £1.09.

This has fed through to what patients pay over the counter. Picard gave the example of a pharmacy that charged £1.19 before the war for a pack of 32 paracetamol and now charges £1.50.

For cetirizine, Picard’s purchase price has almost doubled since January, from 19p for a pack of 30 tablets to 37p now, and some distributors are charging as much as £3.

Allergy sufferers could face more price increases by May or June, when the main hay fever season hits. However, Picard advised customers against panic buying and stockpiling medicines, arguing that would create shortages and drive up prices even further.

Community pharmacies make 90% of their money from dispensing NHS prescriptions and are reimbursed for selling them at fixed prices.

However, if the government agrees an item has risen significantly in cost, it can increase the amount pharmacies are paid back. In March, a record 230 items were on this price concessions list, said Picard, including blood pressure and anxiety drugs, antidepressants and painkillers such as codeine and co-codamol. That compared with 90 in the same month last year.

However, paracetamol was not one of them, despite being one of the most popular medicines, with 1.3m packs prescribed every month in England. The government reimburses only 49p to community pharmacies for dispensing a prescribed 32-pack of paracetamol. Cetirizine was also not on the concessions list.

“It means that the cost of medicine is soaring and ends up being pharmacies dispensing at a loss,” Picard said, adding that 1,400 had been forced to close since 2020 and they continue to close at a rate of one or two a week.

Higher supplier prices also mean a bigger medicines bill for the NHS – through its own purchases and pharmacy reimbursements – as well as for health systems abroad, at a time when budgets continue to be stretched.

While prices for generic drugs are often cheaper at supermarkets, and can cost less at online pharmacies before delivery costs are added, Iran war costs and supply issues are likely to push these up too. More expensive branded versions could record even bigger jumps.

Mark Samuels, chief executive of Medicines UK, which represents the manufacturers supplying 85% of NHS prescriptions, said: “While the Iran conflict has not yet led to immediate or widespread medicine shortages for the NHS, this is due to stock already held in UK warehouses.

“As manufacturers move to replenish these stocks, transportation costs have risen by 700%, and some chemicals needed for manufacturing are in very short supply … If the conflict continues, we will inevitably see rising prices or shortages of essential medicines. This could be as soon as the next few weeks.”