With many patients with multiple sclerosis (MS) increasingly turning to herbal drugs and supplements to treat their disease, for which there is no cure, a recent review evaluated the safety of these alternative therapies.
Because there is no cure for multiple sclerosis (MS), patients with the chronic demyelinating disease often turn to herbal drugs and dietary supplements to augment their prescribed medications, highlighting the need for patient education in this space, especially with more and more turning to these alternative treatments.
Results from a recent systematic review, published in Phytotherapy Research, could serve as potential guidelines regarding the safety of mixing 14 conventional MS medicines (disease-modifying treatments) and herbal drugs or supplements, its authors note.
Following their review of 129 papers identified from PubMed and Web of Science through October 31, 2019, the authors came up with recommendations on what to avoid, potential interactions to monitor, and what is safe and had no significant drug-drug interactions (DDIs). The herbal drugs and supplements they included were based on their appearance in the literature and available interaction information.
Cannabis use while taking selective serotonin reuptake inhibitors (SSRIs) or nonsteroidal anti-inflammatory drugs should be monitored because of the interaction potential. For example, although taking a 400-mg dose of modafinil (Provigil), which is used off label in patients with MS, plus a 15-mg dose of oral Δ9-tetrahydrocannabinol (THC) is considered safe, chronic use of THC with aspirin, naproxen, and indomethacin in vivo can reduce the latter’s efficacy and potency.
In addition, chronic cannabis use with SSRIs can lead to vasoconstriction, “suggesting that before prescribing drugs affecting serotonergic transmission, the patient's use of cannabis should be addressed,” the authors stated.
Only clinically insignificant interactions were found for simultaneous use of cytochrome P450 1A1, CYP1A2, and CYP1B1 and cannabidiol and cannabinol in vitro. No interactions were found between cannabis and CYP3A4.
Daily recommended doses of Panax ginseng and Ginko biloba should not be exceeded, the authors noted. This is based on reports of bleeding events involving the brain and eyes with concomitant use of ibuprofen and G biloba or aspirin and G biloba, respectively. G biloba extract has also been shown to increase the hepatotoxicity of paracetamol in vitro.
For P ginseng, the authors found that a 0.5-mL/kg dose of Panax notoginseng saponins significantly induced CYP1A2 activity in rats, but that P ginseng extract did not significantly affect CYP1A2 in vivo. In addition, significant DDIs were not seen between drug-metabolizing CYP enzymes and a purified ginseng extract in another study.
The authors recommend ongoing evaluation of potential risks when patients are considering higher doses of herbal remedies and supplements, with their review also covering recommendations on turmeric, ginger, cranberry, vitamin C, vitamin D, fatty acids, probiotics, melatonin, and glucosamine.
“The increasing use of herbal drugs and dietary supplements among MS patients makes it crucial to establish whether there are safety risks associated with simultaneous use of disease-modifying drugs and herbal drugs and/or dietary supplements,” they concluded. “The findings in this review support the need for more studies regarding interactions between disease-modifying MS drugs and herbal drugs and/or dietary supplements.”
Overall, the lowest risks of DDI potential were seen for patients on conventional MS drugs who also were taking ginger, cranberry, vitamin D, fatty acids, turmeric, probiotics, or glucosamine.
Petersen MJ, Bergien SO, Staerk D. A systematic review of possible interactions for herbal medicines and dietary supplements used concomitantly with disease-modifying or symptom-alleviating multiple sclerosis drugs. Phytother Res. Published online February 24, 2021. doi:10.1002/ptr.7050