Can You Use Marijuana If You Take Morphine?
Article written by
Dipak HemrajHead of Research and Education
Content reviewed by
Dr. Lewis JasseyMedical Director - Pediatric Medicine
It is possible to use marijuana if you take morphine but talk to your doctor before doing so. Morphine is a powerful analgesic (pain reliever) used to treat acute and chronic pain. While very effective, morphine and other prescription opioids are highly addictive and carry a risk of abuse.
There is increasing evidence that medicinal cannabis can reduce a person’s dependency on opioids for pain relief and improve other symptoms associated with chronic pain.
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What Is Morphine?
Morphine is a naturally occurring opiate found in the resin of opium poppies. It was isolated in the early 1800s and has since been used as an analgesic. It binds to opioid receptors in the central nervous system to relieve pain perception, severity, and emotional response.
Morphine is used to manage ailments like cancer pain and chronic non-cancer pain. It is only available through a doctor’s prescription and may be administered in many ways, including orally, through inhalation, intravenously, and more.
Opiates vs. Opioids
Opiates are naturally derived from plant material and include morphine, opium, and codeine. Opioids are synthetic compounds that also bind to opioid receptors; these include drugs like oxycontin, heroin, and fentanyl. Both opioids and opiates carry an increased risk of addiction. The misuse of opioids is so high that it has fueled a public health crisis called the opioid epidemic.
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Uses and How It Works
Morphine is one of the most effective ways to treat both short-term (acute) and long-term (chronic pain) pain. It can treat various pain types, including nerve (neuropathic pain) and tissue damage (nociceptive pain).
It is a common therapy used in:
- Cancer treatment
- Palliative care
- Post-operative care
- Birth
Morphine works by interacting with the multiple opioid receptors in the brain, including the mu-opioid receptor (MOR), the kappa-opioid receptor (KOR), and the delta-opioid receptor (DOR). By binding to these receptors, morphine blocks the transmission of nociceptive signals (caused by injury or physical damage) traveling back to the brain.
The most common effects of morphine include:
- Analgesia (pain reduction)
- Sedation (this can range from calmness, reduced irritability, and tiredness to unconsciousness)
- Euphoria (elation, intense happiness)
- Physical dependency
When taking oral morphine tablets, users will generally feel the effect in 30-60 minutes. Morphine reaches peak serum concentrations after 60 minutes and will provide pain relief for four to six hours. Slow-release tablets may take longer to work but will last up to 12 to 24 hours per dose.
Potential Benefits and Risks of Mixing Cannabis and Morphine
While morphine is a strong painkiller, it is highly addictive and, like other opioids and opiates, it is often abused. For this reason, long-term use of morphine for chronic pain should be avoided when possible. But for many, it is the only effective way to manage pain and maintain quality of life.
Potential Benefits
Opioid use disorder is associated with higher rates of morbidity (disease) and mortality. Increasing scientific evidence suggests that cannabis use may help long-term opioid users reduce their dependence on morphine and decrease their required opioid dose. This is often termed an “opioid-sparing” effect.
Cannabis is an analgesic that modulates nociceptive pain reception, the inflammatory response, and endogenous opioid receptors.
Observational studies in the U.S. suggest that the legalization of recreational cannabis coincided with a reduction in the use of prescription drugs and opioid-related mortality in Colorado. A recent systematic review on treating non-cancer chronic pain found a 64%-75% reduction in opioid dosage when taken alongside medicinal cannabis.
Combining cannabis and morphine may also help people improve symptoms associated with chronic pain, such as:
Improving these parameters may help reduce high stress levels often seen in those who suffer from chronic pain, improving quality of life.
Potential Risks
Cannabis can cause adverse effects when taken alongside certain drugs. This is because tetrahydrocannabinol (THC) and cannabidiol (CBD) interact with cytochrome P450 (CYP) enzymes. These enzymes are primarily found in the liver and help our bodies process pharmaceutical drugs, including opiates.
Morphine also relies on an enzyme called UGT2B7 to convert it into its more active form. CBD is known to inhibit this enzyme, which could lead to lower levels of active metabolite in the bloodstream, lessening the analgesic effect of morphine.
However, there is little evidence to prove this theory, and some research indicates that the opposite effect is seen. One study has shown that combined cannabis and morphine therapy improves analgesic properties without increasing opioid metabolite levels, meaning that the synergistic effect of cannabis and opioids may come from another mechanism.
Taking medicinal cannabis does not come without side effects. Those taking both cannabis and morphine should consider the following:
- Cannabis will impact driving and operating heavy machinery.
- THC carries both analgesic and psychoactive properties. Those with a family history of psychiatric disorders may not respond well to medical marijuana.
- Cannabis can impact concentration and memory.
Cannabis may enhance morphine’s sedative effects and increase the chances of overdose. However, medical cannabis may also reduce reliance on morphine and decrease the amount needing to be taken.
What to Do If You Need to Use Both
Luckily, medicinal marijuana use has little proven effect on the metabolism of morphine and other opioids, making it relatively safe to combine both therapies. However, it is wise to taper morphine if you are using medical cannabis simultaneously to reduce the risk of over-sedation and possible overdose.
You must talk to your doctor if you are taking morphine and want to introduce cannabis. Cannabis can interact with many medications and interfere with their metabolization. Additionally, your morphine dosage will need to be lowered slowly to avoid opioid withdrawal symptoms like nausea, insomnia, diarrhea, and more. Do not stop taking morphine without your doctor’s consent.
Oral ingestion of cannabis through things like oil drops or alcohol-based tinctures is the preferred method of consuming medical cannabis (as opposed to cannabis smoking) for the following reasons:
- Commercially prepared products have more accurate dosage information, usually mg/mL.
- There is less risk of respiratory harm caused by smoking or vaping.
- The effect of ingested cannabis lasts longer than when inhaled. You can expect relief for five to eight hours when ingested instead of two to three hours when inhaled.
- Isolated CBD allows patients to remove the intoxicating component (THC) from daytime routines.
The type of cannabinoid you should include will depend on the symptom you want to treat. CBD is an anti-inflammatory and may help reduce pain from inflammation; CBD is non-intoxicating and can be safely used during the day. Medicinal cannabis that contains THC often causes drowsiness and sedation. Taking THC-containing cannabis in the evening will help patients sleep and prevent unwanted effects of drowsiness during the day.
When introducing medicinal cannabis into your routine, it’s important to start low and go slowly. The general recommended doses for CBD start at 5-10 mg one or two times per day. At night, 2.5 mg of THC can be taken to help sleep. THC doses can gradually be titrated up by 1-2.5 mg every two to three days until an effective dose is achieved.
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The Bottom Line
Morphine is a potent analgesic drug that allows patients to manage acute and chronic pain. While effective, it also has addictive properties, making this a potentially dangerous narcotic medication. Clinical studies suggest that medical cannabis could be taken alongside a standard morphine treatment plan to improve analgesic effects and reduce the dose of morphine required.
While there is little evidence that cannabis has harmful interactions with morphine, it is essential to consult your doctor before introducing it, as cannabis does interact with many other drugs. The safest and most effective form of medicinal cannabis for pain relief is isolated cannabinoids or whole-plant extracts taken through oral administration.
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Frequently Asked Questions
What can you not take with morphine?
Do not consume alcohol or other central nervous depressants when taking morphine, as this can increase the likelihood of severe side effects and overdose. Head to the FDA’s prescribing information highlights for a complete list of medications and substances to avoid while taking morphine.
How long does morphine stay in your system?
Multiple factors may alter the metabolic rate of morphine. Morphine will stay in:
- Blood for up to 12 hours (standard dose)
- Urine for two to three days
- Hair for up to 90 days
