About one-third of 450 patients reported in a national survey that they could not access marijuana legally under federal rules, said PhD student Rielle Capler.
"They really want to be able to use this medicine legally," she said.
"They've expressed patience and understanding that there are some growing pains, but in the meantime they're also sharing that it's really impacting ... their health and well-being."
The study, led by Capler and UBC nursing Prof. Lynda Balneaves, looks at the impact of shifting federal regulations on patients. While the results are preliminary, Capler said many participants reported facing barriers including cost and supply.
Canadian marijuana patients have faced regulatory upheaval over the past year. The old rules, the Medical Marijuana Access Regulations (MMAR), allowed licence holders to grow pot themselves or find designated growers.
The regulations were to be replaced in April 2014 by a new program, called the Marijuana for Medical Purposes Regulations (MMPR), which requires patients to buy cannabis from commercially licensed producers.
But a court injunction has kept the old program alive for already-enrolled patients, until a constitutional challenge of the new rules could be heard. Advocates are eagerly awaiting a decision in Vancouver's Federal Court.
Only about an eighth of survey respondents are enrolled in the new program, said Capler.
She said one major issue is affordability, noting the old program allowed patients to grow their own marijuana at a cost of about $2 a gram, compared to purchasing it at about $8 to $10 a gram through the new program.
Other issues include difficulty getting a doctor's approval in rural areas and inadequate supply from the larger companies that operate under the MMPR.
"People don't want to be breaking the law to get the medicine they need, so patients have expressed a lot of stress and anxiety around potentially having to do that," she said.
Many patients are turning to dispensaries, which are abundant in Vancouver but technically illegal. These dispensaries do require a doctor's confirmation and have standards around quality of supply.
Cannabis company Kaneh Bosm has also announced that it will bring two high-tech marijuana vending machines to Vancouver, though it isn't disclosing where they will be located yet.
The company's president, Michael Martinz, said the machines are unlike others already operating in the city because they have an armoured steel front, a touch screen and a system allowing users to swipe their ID and create a personal information number.
"Our units are more of a combination of a bank ATM and a vending machine," he said.
The BC Pain Society installed Canada's first pot vending machine last May at its Commercial Drive location in Vancouver, where director Chuck Varabioff said it has made more than $1 million so far.
He said the product is safer in a vending machine because it is sealed in double tamper-proof packaging, so it hasn't been touched by multiple people before a patient buys it.
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