Canadian pharmacists are warning of a worsening drug shortage that they say has led to increased difficulties in locating medication for patients which, in some cases, has compromised patient care.

In a new national survey released Monday, 66 per cent of doctors reported that a national drug shortage had worsened since 2010, while more than 94 per cent of pharmacists reported having difficulty locating a medication for a patient in the previous week.

Of the pharmacists surveyed, 41 per cent said drug shortages had compromised their patients’ health. Both the doctors and pharmacists surveyed warned that in addition to delaying access to medication, shortages often mean patients are stuck with less-effective drugs. The use of alternate drugs can also increase the risk the patient has an adverse reaction, they said.

The findings come from a survey of more than 1,070 members of the Canadian Pharmacists Association, Canadian Medical Association and the Canadian Society of Hospital Pharmacists.

The three organizations warned that drug shortages divert resources from patient care, as doctors and pharmacists spend time sourcing alternate medications and treatments.

“Patients are suffering, and the ability of health providers to deliver quality care for all Canadians is being compromised," Doug Sellinger, president of the Canadian Society of Hospital Pharmacists, said in a statement.

"The efforts of healthcare professionals to lessen the impact on patients have come at the cost of diverting personnel from other areas of care; this diversion is not sustainable.”

Over the past few years, hundreds of drugs -- from antibiotics to chemotherapy -- have been in short supply in Canada, despite a pledge by pharmaceutical companies to make information about looming or ongoing shortages more publicly available.

Current regulations only require pharmaceutical companies to provide 30 days’ notice when they plan to discontinue a drug, despite calls from pharmacists and other stakeholders to increase that time frame to six months.

Under pressure from Ottawa in 2011, drug companies agreed to make information about shortages available via websites such as Saskatchewan Drug Information Services, Vendredi PM and the Canadian Drug Shortage Database.

Despite this, the Canadian Pharmaceutical Association warned last fall that more than 250 drugs remained in short supply, including the epilepsy drug Zarontin, which Canadian pharmacies first began having trouble obtaining in 2010.

Last week, the president of the Canadian Epilepsy Alliance wrote a letter to Health Minister Leona Aglukkaq warning of another shortage of an anti-seizure drug: clobazam.

Gail Dempsey said patients are reporting difficulties obtaining the drug at their local pharmacies, and are being told that the medication may not be available until as early as February, or as late as the end of April.

“Canadians who have prescriptions for clobazam are at risk,” Dempsey wrote. “The product monograph for clobazam indicates that this drug cannot be stopped abruptly. What is being done to ensure the safety of the people who rely on clobazam as the medical treatment for epilepsy?”

Sarah Begin, who was diagnosed with adult-onset epilepsy in August 2011, said she began having trouble filling her clobazam prescription a few months ago. The 25-year-old could only get enough to last for a week, maybe two, and was often told the medication was on back order.

A couple of weeks ago her pharmacy had none to give her, and another local shop only had a week’s supply of the more expensive brand name in stock. She took her last pill on Sunday.

“This is the first time I’ve been on any kind of medication where it’s something that I need regularly and that I can’t go without,” Begin, a freelance singer and teacher, told CTVNews.ca.

On Monday, Begin and her neurologist decided she would try to go without the medication in the hopes that another drug she takes will be enough to keep seizures at bay. But her doctor has warned her that not only could they return, but she could also suffer from seizures related to quitting the drug so abruptly.

“I’ve been seizure-free since September,” Begin said, adding that, “the prospect of starting to have seizures again is terrifying.”

In her letter to Aglukkaq, Dempsey said there are two other anti-seizure medications currently in short supply, oxcarbazepine and methsuximide, adding “there could be other anti-seizure drugs in shortage of which we are not aware.”

Dempsey said the shortages, combined with unclear resupply dates, make it difficult for doctors to come up with an adequate treatment plan for their patients.

The agencies involved with Monday’s survey joined Dempsey in calling for a better system for reporting and managing drug shortages.

"Our organizations are calling on governments, industry, and other stakeholders to continue working towards developing effective, sustainable solutions to dealing with drug shortages," Paula MacNeil, president of the Canadian Pharmacists Association, said in a statement.