What is the efficacy of cannabis (marijuana) in managing pain?

From the Guidelines

Marijuana may be considered as an effective treatment for certain types of pain, particularly neuropathic pain, in appropriate patients, with a weak, moderate recommendation. The primary active compounds in marijuana, THC and CBD, interact with the body's endocannabinoid system and other pain pathways to provide pain relief 1. For neuropathic pain, doses typically range from 5-10mg THC with equal or higher amounts of CBD, starting low and gradually increasing. Common administration methods include smoking/vaporizing, oral preparations, and topicals for localized pain. However, the potential benefits of marijuana need to be balanced with the potential risks of neuropsychiatric adverse effects at higher doses, the harmful effects of smoked forms of cannabis in patients with preexisting severe lung disease, and addiction risk to patients with cannabis use disorder 1.

Some key points to consider when using marijuana for pain management include:

• Starting with low doses and gradually increasing as needed
• Using caution when combining marijuana with other medications
• Avoiding use during pregnancy or in patients with certain psychiatric conditions or heart disease
• Considering marijuana as an adjuvant analgesic or for refractory pain conditions, rather than as a first-line treatment 1
• Being aware of the limited high-quality evidence and potential side effects, and monitoring patients closely for adverse effects 1

It's also important to note that current evidence suggests medical cannabis may be more effective for patients with a history of prior cannabis use 1. Additionally, the American Society of Clinical Oncology recommends considering medical cannabis as an adjuvant analgesic or for refractory pain conditions, but notes that there is insufficient evidence to recommend it for first-line management of chronic pain in cancer survivors 1.

From the Research

Efficacy of Marijuana for Pain Management

• The efficacy of marijuana for pain management is a topic of ongoing research, with some studies suggesting that it may be effective for certain types of pain, such as neuropathic pain 2.
• However, other studies have found that the evidence for the efficacy of marijuana for chronic pain is limited, and that more research is needed to fully understand its potential benefits and risks 3, 4.
• A review of the literature found that there is low-strength evidence that cannabis alleviates neuropathic pain, but insufficient evidence for other types of chronic pain 2.
• The American College of Physicians has issued best practice advice for clinicians counseling patients about the use of cannabis or cannabinoids for chronic noncancer pain, including recommendations for patient subgroups for whom the harms of cannabis or cannabinoid use are likely to outweigh the benefits 5.

Safety and Risks of Marijuana for Pain Management

• The safety and risks of marijuana for pain management are also a topic of ongoing research, with some studies suggesting that it may be associated with an increased risk for adverse mental health effects, such as psychotic symptoms and short-term cognitive impairment 2.
• Other studies have found that marijuana may be safer than opioids for managing chronic pain, with no overdose deaths reported 4.
• However, the long-term physical harms of marijuana use are not well understood, particularly in heavy or long-term users, or in older populations 2.
• The American College of Physicians recommends that clinicians advise patients against the use of inhaled cannabis to manage chronic noncancer pain, and against starting or continuing to use cannabis or cannabinoids in certain patient subgroups, such as young adult and adolescent patients, and patients with current or past substance use disorder 5.

Clinical Guidelines and Recommendations

• Healthcare professionals require education and training, as well as clinical guidelines that provide evidence-based information about the efficacy, safety, and appropriate dosage of marijuana products for pain management 3.
• The American Society of Pain and Neuroscience has summarized the evidence for the use of medical cannabis for various pain conditions, including cancer-related pain, neuropathic pain, and chronic nonmalignant pain 4.
• The American College of Physicians has issued best practice advice for clinicians counseling patients about the use of cannabis or cannabinoids for chronic noncancer pain, including recommendations for patient subgroups and for the safe use of cannabis or cannabinoids 5.