Donepezil is licensed in the UK but is not widely available on the NHS, leading to some patients taking out private prescriptions.
The drug, which has been shown to delay the progress of the disease, costs the NHS pounds 68 for a month's supply. But a team at the Research Institute for the Care of the Elderly, in Bath, which carried out a survey of 62 chemist shops, found that patients were being charged anything from pounds 68.32 to pounds 168.78. A second team of psychiatrists say many people in Surrey are having to pay pounds 200 a month.
"Doctors prescribing Donepezil in good faith will be astonished at the mark-up being charged by some pharmacists," says the Bath team in a letter to the British Medical Journal.
A spokesman for the Pharmaceutical Society said: "Pharmacists are professional people and are at liberty to charge the fee that they see fit."Reuse content