High street chemists are facing a shortage of hay fever medicine due to the lack of a key ingredient.
As the Met Office warned of rising pollen levels in parts of England, it emerged that stocks of chlorphenamine maleate, an active ingredient in brands such as Piriton, are running low.
“However, we are expecting this to be resolved soon and new deliveries are expected in the coming weeks,” the company said in a statement.
Piriteze, Benadryl and Allacan are all said to be in good supply.
Royal Pharmaceutical Society president Claire Anderson said: “Chlorphenamine maleate is just one component of a few hay fever tablets, including Piriton, which is not a first line choice for treating hay fever for adults as it is more likely to make patients drowsy.
“Medicines shortages are not a new problem, and is something pharmacists and pharmacy teams have to manage and deal with on a daily basis, and have done for a long time.
“This can be for a multitude of reasons, including manufacturing issues, global demand or disruption with the supply chain.”
The shortage comes as the Met Office warned that parts of England, including London and the South East, will experience high levels of pollen this week. Levels are expected to peak on Friday.
Pollen is an extremely fine powder released by plants during their reproductive cycle which is spread by insects and the wind.
It causes irritation, inflammation, sneezing, coughing, a runny nose and red or watery eyes among those who are allergic to it.
Around 16 million Britons are thought to suffer from hay fever across the UK, according to the Natasha Allergy Research Foundation.
Britons who suffer from hay fever have been told to check with their pharmacist whether their preferred remedy has been affected by the shortage.