Roche withdraws blood pressure drug due to interactions risk

A blood pressure medication used by up to 2,000 Irish patients has been withdrawn by its manufacturer because of health risks caused by interactions with other heart drugs.

There have been 43 deaths amongst the 400,000 patients worldwide who take the drug, Posicor, and frequent reports of serious side-effects when taken with other medications.

No such deaths or drug interactions have been recorded in Ireland, however, according to the Irish Medicines Board.

Patients taking the drug should not discontinue its use but should consult their doctors immediately so that alternative treatments can be given, according the board. They should also report any side-effects to their doctors.

Roche Pharmaceuticals, which manufactures Posicor, yesterday announced its voluntary and complete withdrawal. It would no longer be available to the public, according to a spokesman for the company's Irish subsidiary, Roche Products (Ireland) Ltd.

"The drug went through extensive pre-marketing testing. On the post-marketing surveillance an increasing number of drug interactions were coming up," he said.

Posicor, also known as mibefradil, is used to lower blood pressure. It also reduces the pain associated with angina. It was authorised for use here by the Irish Medicines Board in 1997.

No reports of suspected interactions linked with Posicor were made here, according to a statement from the board.

Drug companies warn prescribing doctors of interaction risks in the labelling supplied with the medication. "However, with respect to Posicor, Roche believes that the complexity of such prescribing information would make it too difficult" to do this, the company said in a statement.

Roche advised patients to speak to their doctors before discontinuing Posicor treatment. It also warned against adding "any new medication to their present treatment without contacting their doctor."

The company had agreed to "an orderly withdrawal" of the drug from the marketplace, according to the board. "As always, the Irish Medicines Board recommends those taking medication to follow carefully any directions, to read any supplied information and to consult their doctor or pharmacist if in doubt."

The drug is sold in 38 countries and has been available for about three years.

There was no firm evidence that the deaths of patients using the drug had been caused directly by it. The interactions and the resultant side-effects were, however, associated with use of Posicor.