Dear Dr. Roach: I live in a large community. More and more of my peers are using THC gummies sold over the counter at smoke shops as a substitute for smoking marijuana. Are there any studies being conducted on the safety of imbibing these small amounts of THC? Also, are there any studies being conducted on other drug interactions when imbibing these small amounts of THC?
K.B.
The question of whether cannabis is safe and effective for treatment of many medical conditions is largely open-ended, although there is strong evidence that purified cannabis extracts (especially cannabidiol or CBD, a nonpsychoactive component of cannabis) are successful with some types of epilepsy. Cannabis may be smoked, vaped or consumed. As you say, many users are turning to edibles for both recreational and medicinal use. There are many forms of edibles, not just “gummies.”
Although edibles avoid the inhaled smoke that can cause lung damage, edible forms of cannabis have the potential for at least two types of increased toxicity. The first is in children who mistake the edibles, especially gummies, for candy and become dangerously intoxicated. These products must be kept away from children, regardless of the laws in your state. The second is that inexperienced users may not wait long enough for the ingested cannabis to take effect (some users will not notice effects for up to 90 minutes or more). So, they decide to ingest additional doses and end up consuming far more THC, the psychoactive component of cannabis, than they expect.
The amount of THC in edibles ranges from less than 1 mg to 10 mg, or more, per dose. Even a single 10 mg dose may not be small for some people, so inexperienced users should start low and increase slowly. Emergency room visits for intoxication are much more common with THC edibles than with smoked cannabis; however, inpatient hospitalization is rarely required in adults.
The data on drug interactions with cannabis are incomplete. I found evidence for potential drug interactions with several drugs, especially warfarin (Coumadin), clobazam, theophylline, clozapine and olanzapine. By no means is this a complete list, as there may be others. Small amounts of THC are less likely to cause significant drug interactions.
Dear Dr. Roach: I am 68, have an autoimmune disease (rheumatoid arthritis), and have been on Enbrel for over 20 years. I am still masking in public due to my age, my health condition and Enbrel. I have read a number of articles citing recent studies on masking and whether it protects the elderly and immunocompromised. Do you advise I continue?
A.E.
I don’t think there is any real doubt that masking has been an effective way to reduce COVID risk for individuals. What has been debated is whether mask mandates help communities, and a recent review of the published, controlled trials was unable to show whether there was a benefit, although other types of studies suggest a benefit.
For individuals, however, the risk of acquiring COVID is about 80% less with a high-quality mask, rather than going without a mask. Wearing a mask is most important for people at high risk. As you correctly say, you have multiple risks that make COVID prevention more important. Depending on the amount of COVID transmission and exposure in your community, mask-wearing will have, more or less, absolute benefit. However, given your risks, continuing to wear a mask while near large groups of people indoors remains wise, as long as there are moderate or high levels of transmission where you are. Levels of transmission can be found here: www.cdc.gov/coronavirus/2019-ncov/your-health/covid-by-county.html.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected]
