Sandoz informed Health Canada on Wednesday that an unidentified Toronto hospital had reported that one package of 2 mg/ml injectable morphine sulfate had been found to contain ampules labelled as 0.2 mg/ml isoproterenol hydrochloride injection in addition to ampules labelled as containing morphine.
"We have not received reports of this affecting any patients, which is obviously the most important thing," said Steve Outhouse, a spokesman for federal Health Minister Leona Aglukkaq.
"By calling for an immediate quarantine, this will help reduce future risk to Canadians related to these potentially mislabelled drugs," Outhouse said late Wednesday by email.
Inadvertent use of injectable isoproterenol hydrochloride instead of injectable morphine sulphate — a potent painkiller — can result in serious health effects.
Not only would patients not receive their intended morphine therapy, but isoproterenol hydrochloride is a powerful agent associated with a risk of life-threatening abnormal heart rhythms. Other side-effects may include headache, tremor and sweating.
Isoproterenol hydrochloride, which has physiological effects similar to those of the stimulating hormone epinephrine, has a variety of uses, including relieving heart block and cardiac arrest prior to a defibrillator being used to shock the heart so it resumes beating.
Sandoz has told Health Canada that it cannot confirm whether there are other similar packages with mislabelled drug contents, but Outhouse said no other products are affected by the urgent do-not-use warning.
He said the medication is not being recalled, but hospital staff are being told to stop using the drug until further notice.
Health Canada is working with the drug company to determine the scope of the problem and to ensure that other incorrectly packaged products do not make their way into the drug-supply system. The federal agency has also informed the provinces and territories.
In a conference call Wednesday evening, B.C. Health Minister Mike DeJong sought to reassure patients in his province that they were unlikely to be affected by the mislabelling, or the morphine quarantine.
"There are and will continue to be alternative morphine products available, and the best information I have at this point is that we do not believe there will be a shortage," he said.
DeJong added that B.C. health authorities were taking every precaution possible to ensure patients continue to receive the right medication and that surgeries are not delayed or cancelled.
"At this point I am not aware, nor have I been advised that this will lead to the postponement of any procedures, or affect patient care in the immediate," he said.
Sandoz Canada, which supplies the majority of injectable medications used in Canada — among them painkillers, anti-nausea medications and antibiotics — is at the centre of a national drug shortage caused by quality-control problems at its Boucherville, Que., plant.
The affected products are:
—Morphine sulfate injection USP, 2mg/ml (1ml), DIN 2242484, UPC 057513056420, Lot CC2824 exp. 2014-12
— Isoproterenol hydrochloride injection USP, 0.2 mg/ml (1ml), DIN 897639, UPC 057513046001, Lot CB8787, exp. 2012-11