He said some patients did not place value on the drugs or the need to take them, partly because they were free.
He told the conference: “If that which we prescribe is thought to have little value, then I think there’s a risk of poor compliance and increased risk.”
BMA chairman Dr Hamish Meldrum supported the motion and suggested the value argument could also suggest there was no value to a heart transplant, which is also free on the NHS.
He said: “That is not an argument for supporting an unfair tax on illness, which is what prescription charges have become.”
A Department of Health spokesman said the charges were a source of “valuable income” to the NHS.
She said: “Help is available for people who have to pay the prescription charge, but need extensive or frequent prescriptions.”
Pre-payment certificates can help spread costs by direct debit, in certain cases.
A further review of fee exemption is due to be completed this autumn.
