When it comes to medical marijuana/cannabis, a physician can play a key role in helping guide you and understand your options in treatment. Treatment can be different depending on the effects, and it’s important to always consult a qualified physician to review your medical history and medications.
For example, both THC and CBD can affect other medications that patients may be taking, but CBD has a much stronger effect. Cannabinoids of most therapeutic interest are THC and cannabidiol. Minor cannabinoids include cannabigerol, cannabichromene, and tetrahydrocannabivarin.
Other drugs can affect THC and CBD levels:
-CYP3A4 inhibitors slightly increase THC levels.
-CYP3A4 inducers slightly decrease THC and CBD levels.
-CBD, but not THC, is metabolized by CYP2C19
THC can affect other drugs and is a CYP1A2 inducer. It can also decrease serum concentrations of clozapine, duloxetine, naproxen, cyclobenzaprine, olanzapine, haloperidol, and chlorpromazine.
CBD can affect other drugs and is a potent inhibitor of CYP3A4 and CYP2D6. As CYP3A4 metabolizes about a quarter of all drugs, CBD may increase serum concentrations of macrolides, calcium channel blockers, benzodiazepines, cyclosporine, sildenafil (and other PDE5 inhibitors), antihistamines, haloperidol, antiretrovirals, and some statins (atorvastatin and simvastatin, but not pravastatin or rosuvastatin). CYP2D6 metabolizes many antidepressants, so CBD may increase serum concentrations of SSRIs, tricyclic antidepressants, antipsychotics, beta blockers and opioids (including codeine and oxycodone).
A special note about Warfarin (coumadin): Both THC and CBD increase warfarin levels. Frequent cannabis use has been associated with increased INR.
Your physician should review your entire medical history to help guide you. You wouldn’t climb Everest without a sherpa, so make sure your physician is a well-qualified guide.