‘Is There Enough Evidence To Prescribe Medical Marijuana?’

Some conditions for which cannabis-based treatment has been advocated include epilepsy, neuropathic pain and chronic widespread pain.

KUALA LUMPUR, Nov 11 — There is still a dearth of evidence from high-quality research to endorse the general use of cannabis for the treatment of pain, according to the Malaysian Association for the Study of Pain (MASP).

MASP president Dr Mary Suma Cardosa, in a statement to CodeBlue, said Health Minister Khairy Jamaluddin’s recent acknowledgement in Parliament on the use of medical cannabis should not be interpreted as a “blanket endorsement” of the use of medical marijuana for the treatment of a variety of medical conditions, including pain.

“MASP notes that while the Minister of Health has stated that cannabis containing products can be imported and used in Malaysia, he also stated that the product must apply to be registered in compliance with the law, and that it can only be prescribed by a registered medical practitioner,” Dr Cardosa said.

Dr Cardosa said the big question is whether there is enough scientific evidence for medical practitioners to prescribe medical marijuana, and what conditions have been shown to respond to this treatment.

Some conditions for which cannabis-based treatment has been advocated include epilepsy, neuropathic pain and chronic widespread pain as well as appetite problems, nausea and vomiting and pain in cancer patients.

The International Association for the Study of Pain (IASP), an international organisation with over 5800 members from 134 countries, in a statement issued on March 18 this year, stated that a comprehensive review of research on the use of cannabinoids to treat pain found there is lack of adequate evidence to support the general use of cannabinoids for the treatment of pain.

The MASP is a chapter of the IASP and a founding member of the Association of Southeast Asian Pain Societies (ASEAPS), a federation of the IASP.

In a non-technical review summary on the use of cannabis and cannabinoids for pain relief, the IASP said there is “not enough high-quality human clinical safety and efficacy evidence” to allow the general use of cannabis and cannabinoids for pain currently. 

“Laboratory research on a wide variety of cannabinoids holds promise for effective pain relief, but most have not yet been tested in pain patients,” the statement read.

“While IASP cannot endorse the general use of cannabinoids for the treatment of pain at this time, we do not wish to dismiss the lived experiences of people with pain who have found benefit from their use,” said Andrew Rice, professor of pain research at Imperial College London and chair of the IASP’s Presidential Task Force on Cannabis and Cannabinoid Analgesia.

The MASP fully supports the position of the IASP on this, as the statement is based on rigorous review of data and science, Dr Cardosa said.

The group stressed that management of chronic pain, including neuropathic pain and conditions like chronic widespread pain or fibromyalgia, require a multidisciplinary team approach with different modalities of treatment, not just medications.

“(Therefore) cannabis-based medication, even if shown to provide pain relief in specific pain conditions, should not be used alone and should never be seen as a cure for the pain. Instead, all medication used in the treatment of chronic pain should be part of a multimodal approach to pain management, and must include self-management strategies,” Dr Cardosa said.

The MASP welcomes the formation of the bipartisan parliamentary caucus to study medical marijuana so that the decision about the use of medical marijuana is based on science and data.

“The MASP has many members, including pain specialists, with extensive knowledge and experience on this topic, and we hope that the parliamentary caucus, as well as relevant authorities in the Ministry of Health (MOH), will reach out to us for our expert input on the scientific basis for whether to include medical marijuana in the armamentarium of pain medications. 

“Whilst considering the benefits of any medication, we must not forget to also review the possible harms, including long term adverse effects, as many of the conditions deemed to benefit from cannabis-based medicines are long term chronic conditions,” Dr Cardosa said.

Additionally, the MASP recommends that authorities look to the experience of neighbouring Thailand, which legalised the use of medical marijuana in early 2019.

Citing an article published in the journal Pain in 2019, the article stated that well-planned strategies, including education for medical professionals and patients, public awareness campaigns, and an adequate quality-controlled supply of standard cannabis-based medicinal products are needed before the implementation (of policies legalising medical cannabis).

Can Medical Marijuana Replace Opioids?

On whether medical marijuana can replace opioids for the treatment of pain, MASP said morphine remains the gold standard for acute pain and cancer pain treatment.

It said data from MOH’s study on Medicines Utilisation in Malaysia and from estimates of cancer pain prevalence, compiled in the Clinical Practice Guidelines on Cancer Pain Management, showed that the amount of morphine and other opioids used in Malaysia would only treat 20 per cent of more than 15,000 cancer patients estimated to have moderate to severe pain.

“While this data is from quite a while back, the amount of opioids used in the country (per population) has not increased significantly, while estimates of cancer prevalence have increased and thus it is unlikely that the situation has improved,” the group said.

CodeBlue previously reported on growing addiction in Malaysia to prescription painkillers, as narrated by experts, now that locals have greater access to prescribed opioids at pain clinics.

Dr Sivakumar Thurairajasingam, Deputy Head (Education) of Clinical School Johor Baru, Jeffrey Cheah School of Medicine and Health Sciences at Monash University, said he has seen patients addicted to pain pills like oxycodone and pethidine.

“It’s not big enough to substantiate and make a statement that we’re facing a problem, but looking at trends around the world, I think it’s something we have to be careful about,” he said.

In the United States, an Oklahoma court in 2019 ordered Johnson & Johnson to pay the state US$572 million in the first trial involving a pharmaceutical company, in relation to the opioid crisis ravaging the nation.

The MASP said while it is aware of the problem of the “opioid crisis” in the US and other parts of the world, there is inadequate local data to categorically state whether something similar is also occurring in Malaysia.

“We would like to state that the issue of possible inappropriate use of strong opioids for chronic non-cancer pain [however] should not detract from the need to improve the accessibility and availability of strong opioids for the appropriate treatment of moderate to severe acute pain (e.g. after surgery and/or trauma) and cancer pain,” it said.

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