Want to use medical cannabis with over-the-counter (OTC) drugs but are unsure whether the combination will cause any side effects? In this post, we’ll consider a few common OTC meds, and look at how they might react with marijuana. Whenever you mix drugs with other drugs, you run the risk of nasty side effects. While compounds in cannabis (cannabinoids, terpenes) are very safe and non-toxic, certain compounds can still interact with chemicals in OTC drugs.
Therefore, exercising some caution before adopting a treatment plan with medical cannabis and OTC drugs is advised. Contact your doctor before self-medicating, who may have some tips or warnings. The following content is not medical advice, purely an informational resource – we are making no definitive claims about cannabis, just speculating on what may happen from the scientific studies and anecdotal reports we have.
1) Cough and cold medicines
Sometimes, using cannabis alongside OTC drugs for the common cough and cold can have an overly sedating effect on the user. This happens because the body is consuming at least two compounds with sedative properties – the cannabidiol (CBD) from the cannabis, and likely dextromethorphan if using OTC drugs to treat a cough.
The side effects can be amplified when compounds with similar effects are used in conjunction, and in the case of cannabis and cough medicines, this can induce confusion, brain fog, drowsiness and dizziness in the patient. Zicam, Robitussin and NyQuil are all drugs that contain dextromethorphan. Thera-Flu and several other OTC flu treatments contain pheniramine, which has relatable side effects.
Interestingly, research has shown that some non-steroidal anti-inflammatory drugs (NSAIDs) can work to reduce the psychoactive and memory loss side effects that sometimes come from THC. Examples of NSAIDs include aspirin and ibuprofen.
In 2013, a study published in Cell revealed that THC-induced memory impairment is caused by an increase of the COX-2 enzyme. Enzymes are proteins that help the body to break up compounds into smaller pieces, so they can be more easily absorbed. Digestive enzymes break down the compounds in your food, releasing the nutrients in them so you can get the benefit.
The Cell study focused on pro-inflammatory enzyme COX-2 and THC. Both chemicals have links to memory, and research seems to indicate that THC increases the concentration of COX-2, potentially causing short-term memory loss.
Research into NSAIDs found that this collection of drugs inhibits COX-2, and in doing so reduces memory impairment caused by THC. Even more promising than aspirin and ibuprofen is Celebrex, an anti-inflammatory drug that, when combined with THC, treats memory loss issues without diminishing the therapeutic potential of the cannabinoid.
Celebrex is not an OTC drug, and is only accessible via prescription, however some of its reactions with the body are like those of OTC medicines.
3) Allergy drugs
Allergy medicines which contain the antihistamine doxylamine often produce some unpleasant effects when combined with marijuana. Doxylamine is present in several OTC allergy drugs, including NyQuil. Mixing doxylamine with cannabis can cause mental confusion, cognitive impairment, drowsiness and inhibit motor function.
Diphenhydramine, the main ingredient in the allergy medicine Benadryl also causes some unfavorable reactions with cannabis, such as dizziness, confusion and over-sedation. Patients with allergies should also be aware of the Zyrtec brand which contains cetirizine. For a safe side effect-free solution to allergies, experiment with nettle tea.
Is it safe to use CBD with OTC drugs?
You should be suspicious with mixing any other medicines with OTC drugs, including the unassuming, non-psychoactive CBD. Research on the liver and the Cytochrome P450 System suggests that CBD products has an inhibitory effect on enzymes that are responsible for breaking down around three-quarters of the compounds used to make pharmaceutical drugs.
The liver’s primary role is to act as a detoxifier, cleansing the body from toxic compounds. By stopping the breakdown of these chemicals through the stifling of liver enzymes, the body is forced to work harder to remove these substances. The increased toxicity in the body heightens the risk of side effects.
To carry on using CBD in tandem with OTC drugs, reducing both dosages may be necessary – this reduces the number of compounds that the liver enzymes needs to clear, while causing less of an inhibitory effect. However, all OTC drugs contain different compounds, so consulting your doctor about your chosen combination before medicating is a sensible idea.
If you do have a bad experience after mixing OTC drugs with cannabis or CBD, don’t be afraid to let the medical expert who’s examining you know. They are there to help.