B.C. methadone dose change brings risk of overdose

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Laura Shaver has a routine.

Every morning, she goes to a Vancouver pharmacy for a dose of methadone, which she has been prescribed to stem withdrawal symptoms she would feel if she did not take the drug.

As of Feb. 1, the compound she will be taking will be 10 times stronger, as Ms. Shaver and thousands of others enrolled in British Columbia's methadone maintenance program adapt to a new formulation of methadone.

That new formulation will bring B.C. in line with other provinces, including Alberta, that have added Methadose to the lists of medications covered by provincial health care plans. The rationale behind the change is better safety and quality control, because pharmacists will no longer have to mix methadone into a compound solution. But there is also a risk of overdose among prescription and illicit users because of the increased concentration.

"If both the doctors and the pharmacists have to take training in this, that means it is something pretty heavy," Ms. Shaver, president of the B.C. Association of People on Methadone, said in a recent interview.

"So if you can spend all that time doing that, why are you not putting up posters and letting us know about the change?"

Currently, B.C. pharmacists provide methadone in a one-milligram-per-millilitre solution that is typically stirred into an orange-coloured drink that methadone clients consume while they are at the pharmacy or in some cases, take away as "carries." Starting Feb. 1, pharmacists will dispense Methadose. The red, cherry-flavoured solution is a commercial preparation that does not have to be compounded by a pharmacist.

At 10-milligrams-per-millilitre, Methadose is also 10 times stronger than the solution currently used by the nearly 15,000 people who are enrolled in B.C.'s methadone maintenance program to treat their addiction to heroin or other opioid drugs.

Many users do not know about the pending changes, says Ms. Shaver, who has been on methadone treatment for several years.

That lack of knowledge could result in dangerous overdoses and even deaths among prescription users and those who may buy illicit methadone on the street, she says.

Ms. Shaver says her group is working on a poster campaign that will tell people about the new regime.

The provincial Ministry of Health says it is implementing the change to "reduce the risk of errors" associated with the current methadone formula.

Health Canada approved Methadose, which comes in a clear, sugar-free solution or the red variety, in 2012. B.C.'s PharmaCare program will cover the drug starting next month. Costs of the new formulation are expected to remain about the same.

In a December bulletin, the B.C. College of Physicians and Surgeons noted patient safety concerns, including the risk of overdose and the cherry-red colour that resembles other over-the-counter medications.

People in the methadone program can be prescribed the drug to be taken at the pharmacy – a witnessed ingestion – or as "carries" – typically enough for a few days or even a couple of weeks – they can take home. Doses vary from person to person, with the average dose somewhere between 70 to 120 milligrams per day.

At the one-to-one concentration of the current methadone solution, patients were used to drinking an amount of liquid that corresponded to their dosage. If they were to drink the same amount of Methadose as they do of their current compounded solution, they would ingest 10 times the amount of medication.

"It's the volume that's going to be the biggest change for the actual patient," says Dr. Ailve McNestry, deputy registrar with the College of Physicians and Surgeons of B.C.

Both the College of Physicians and Surgeons of B.C., whose members prescribe methadone, and the College of Pharmacists of B.C., whose members dispense it, are expected to help patients understand the changes and precautions, including safe storage. Methadose, unlike the old solution, does not need to be refrigerated and there is a concern about it being mistaken for other, similar-looking drugs such as liquid painkillers or cough syrup.

"Methadone is always supposed to be stored safely, preferably under lock and key – and absolutely under lock and key if there are children in the house," Dr. McNestry said. "That message has always been inherent in prescribing methadone and we expect doctors will continue to give safety advice and pharmacists will continue to repeat that advice."

Despite such precautions, methadone does find its way onto the street and there are abuses in the program. In 2011, the City of Vancouver passed a motion to look into allegations of abuse related to the drug.

Those allegations included claims by Downtown Eastside residents that one pharmacy owner in the neighbourhood, who also owned single-room occupancy hotels, would evict methadone users unless they had their prescriptions filled at his pharmacy.

Pharmacists who dispense methadone receive a dispensing fee – up to a maximum of $10 – as well as up to two cents per millilitre for methadone and $7.70 per claim for each witnessed ingestion, the B.C. Ministry of Health says. At nearly $20 for a typical dose, that could add up to more than $7,000 if someone got his or her prescription filled at the same pharmacy all year.

Doctors, pharmacists, pharmacy owners, methadone users and police got together to talk about the issue and agreed to share information so that the College of Pharmacists could investigate allegations of methadone-related fraud or abuse more quickly, says Councillor Kerry Jang.

The city also reviewed its system for approving methadone-dispensing sites and has turned down several applications since the motion was passed in mid-2011, Mr. Jang said.

"There was enough consistency in the various stories and in what we had been hearing on the street ourselves to know that these abuses were going on," Mr. Jang says. "I don't think anybody really realized, in the medical community, the degree of the abuse – unless you were a physician working in the Downtown Eastside. But the [medical] establishment didn't see it in the same way."

Began

: Methadone Maintenance Treatment was introduced in Vancouver in 1959 and has been adopted across the country and internationally. Health Canada works with provincial and territorial governments to provide access to methadone. Only physicians who have an exemption from the provisions of the Controlled Drugs and Substances Act under the law's Section 56 are allowed to prescribe methadone.

How it works

Methadone can help ease drug withdrawal. A daily dose can prevent symptoms such as anxiety and vomiting for 24 hours.

The rationale

Providing MMT can save money in other areas, such as drug-related crime, jail time and medical treatment. Those "social costs" are estimated to amount to about $45,000 per person each year ; it costs about $6,000 per person annually to provide MMT.

Number of people who took part in B.C.'s 2012-2013 MMT

about 14,800

Number of B.C. pharmacies dispensing methadone

716

Number of B.C. physicians prescribing methadone

473

Current formulation

1 milligram per millilitre

New formulation

10 milligrams per millilitre, 10 times the concentration of compounded methadone

Editor's note: An earlier version of this story stated that pharmacists were paid $7.70 per claim for each witnessed methadone injection. The methadone is ingested in drink form. This version has been corrected.