Health Canada, the country’s regulatory body, on Friday said that GlaxoSmithKline has issued a Dear Doctor letter outlining potential manufacturing issues for six of its drugs. The warning relates specifically to the diabetes drugs Avandamet (rosiglitazone plus metformin) and Avandia (rosiglitazone), the heart medication Coreg (carvedilol), Paxil (paroxetine) and Paxil CR (paroxetine controlled release) for depression, the non-steroidal anti-inflammatory Relafen (nabumetone) and a paroxetine compound distributed by Ratiopharm.

Following quality control problems at GSK’s Puerto Rico plant, these products have been found to contain split pills or inconsistent amounts of active ingredient and, in some cases, bottles and blister packs may contain the wrong medication. GSK and Health Canada say that people with asthma should be particularly careful as accidentally taking a Coreg tablet could result in an increased risk of a serious asthma attack. Coreg is used in the treatment of heart failure and is not prescribed to asthmatic patients, due to the risk of a serious asthma attack. They say the risk to other patients of taking a stray tablet of another medication is believed to be low, but caution pharmacists to manually inspect the drugs when dispensing and advise all patients to check the appearance of their medication before taking.

- Meanwhile, the country’s Globe and Mail newspaper says Health Canada has reportedly requested that more than a dozen pharmaceutical companies provide safety data on their anti-convulsant medications, following concerns there may be a link to an increased risk of suicide. Similar action has also been taken by the US Food and Drug Administration.