This is a balanced article, but it could use some added context and I wanted to add a little more evidence based medicine into the picture. The portrait that is painted of pain medications is very rosy and it is important to understand the very real dangers of the first line pain medications and admit to ourselves that we do not always achieve success with second or third line agents when we are dealing with chronic pain.

“Marijuana is not first line treatment for any condition” — unfortunately, we are dealing with conditions that have poor treatments available. In the case of sciatica, one of the causes of neuropathic pain, the evidence for any treatment is weak. The situation is hardly unique to the cannabinoids.

When we talk about medications for pain, let us examine some of the first line treatments.

Acetaminophen is a common and effective pain medication that is first line for many chronic pain conditions such as arthritis. But it is particularly toxic in overdose, especially in children and the elderly and a recent Toronto Star article points out the dangers of this agent. If it was introduced in the market today, it would never be approved as an over the counter agent.

The best thing that can be said about acetaminophen is that it is far safer than what are typically second line agents, the NSAIDs. These agents come with a high mortality risk, particularly in the elderly, due to gastrointestinal bleeding. Newer agents were said to have less risk of GI bleeding, yet increased the risk of heart attack. In the case of Vioxx, this was an FDA and Health Canada approved agent, that killed tens of thousands. Given the overly close relationship between pharmaceutical corporations and the approving agencies, approval of a drug by a federal agency should not be seen as a measure of efficacy or safety.

Opiates are either second or third line for chronic pain, although based on poor quality studies on relatively short durations. From a previous Health Debate:

She notes Health Canada’s mandate to ensure drugs are safe, and highlights that while the safety of short-term use of prescription opioids for acute pain has been well established, “no one has proven that they [prescription opioids] are safe and effective for long-term chronic, non-cancer pain.”

Codeine should probably be removed from any formulary. It is inconsistently metabolized prodrug that allows the clinician to kill children or prescribe what is essentially a placebo.

Tramadol has been felt to be a useful new agent. But what else are the drug companies hiding besides a oxycontin-like high and unspoken addiction issues?

Oxycontin bears special mention if only for Purdue’s multiple episodes of malfeasance

Most patients are rightly concerned about the high frequency of physical addiction that comes with chronic opioid therapy and a number of CTP patients have expressed their frustration to me that their physician is happy to write a prescription for Percocet, but not for cannabis. Deaths from prescription opiates are particularly high in my health authority (IHA), with the rate of deaths from patients using their own, prescribed antibiotics is the same as the number of people we are losing to drunk driving. Opiates are also much more lethal when combined with alcohol than cannabis.

With regard to federal approval and opiates, we should be very aware of their prominence in the regulatory sphere, including the recent bumping of a critic from a parliamentary prescription drug panel in favor of a representative from Purdue Pharmaceutical, makers of OxyNeo.

Gabapentin can be effective for some people with neuropathic pain. But if you are concerned about the level of literature that supports cannabis, you really should look at the concerns regarding the studies of gabapentin which make interesting reading and have led to massive settlements against the drug company against promotion of their drug for off label indications.

When we get down to this level, we can start to compare agents. In neuropathy, gabapentin has an NNT of 3.8 while low to medium vaporized cannabis showed an NNT of 2.9-3.2 And no risk of overdose. And while many people show inordinate concern about diversion into the black market, the same concern should be applied to both Tramadol and Lyrica

Another issue to address is cost. A bottle of Sativex currently runs at $226.70 (for a 10 day supply, and don’t forget about the mucosal burning with administration) and while ondansetron is a very effective medication for vomiting, the rapid dissolve preparation sells for approximately $7/pill, easily over $200 for a 20 day supply. Either of these could easily create patients costs of several hundred dollars per month, compared to the very low cost of cannabis that is available to the home CTP grower, and will now be banned by the new regulations.

The safety of CTP is also mentioned as a risk, though as a practicing clinician, I would have to rate it as one of the least riskiest drugs I ever prescribe. Aside from the absence of direct toxicity in overdose, any respiratory or malignancy concerns can be removed by vaporization (I think you would find very few prescribers who would recommend smoking). There is no evidence that even smoking cannabis causes COPD any malignancy risk has only been seen in heavy users.

You reference the Dunedin study to support their assertion that cannabis can be associated with a decrease in IQ, but fail to mention the later study that showed that any effect in that study was more easily explained by socioeconomic cofounders. In the same vein, you quote a study from 2003 to support the assertion that cannabis can cause psychosis, yet ignore a Harvard study published this year that does not support your conclusions.

Some note is made of the restrictions on research that have lead to this state of affairs. There have been urgent calls for research into cannabinoid, and yet there has been no weakening of the schedule of these drugs. Cannabidiol is currently Schedule 2 in Canada, despite having no street value or psychoactive effect. This is beyond a third line drug for the treatment of pediatric epilepsies, such as Dravet’s syndrome, and yet has been found to be one of the few things effective in treating these children. There is no provision in the new regulations to produce cannabidiol concentrates that could be used to control the seizures in these Canadian children, forcing them to consider emigrating to have access to this medication.

There is no reason that research couldn’t be carried out here, but not as long as the research material is banned from being produced and likely to get you thrown in jail. The stigma attached to cannabis is also felt by patients who would like to try the edibles, oil and concentrates that are enjoyed by patients in other jurisdictions, but will not be supported by the new Health Canada regulations.

As Canadian physicians it is also important to take a public health approach and look not only at the effects of clinical cannabis on the individual, but also on society. Two recent studies have shown some impressive positive effects on US states that have legallized medical cannabis. Legalizing medical cannabis does result in some spillage into the recreational market, but this has the interesting effect of decreasing the frequency of binge drinking.

States who legalized medical cannabis noted a 10 percent decrease in suicides in males 20-39 that was consistent between states. They were also found to have a 9 percent decrease in traffic fatalities in the year following legalization.

Ian Mitchell, MD, FRCP

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