Chlorzoxazone is used to treat acute painful muscle conditions. It is a type of drug called a centrally acting skeletal muscle relaxant.
Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem contradictory. For clarification, read the full article for details about the summarized interactions.
 Avoid: Reduced drug absorption/bioavailability—Avoid these supplements when taking this medication since the supplement may decrease the absorption and/or activity of the medication in the body. | Broccoli Brussels sprouts Chinese cabbage Garlic Tea Watercress |
| Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results. | Alcohol Caffeine* |
| Depletion or interference | None known |
| Side effect reduction/prevention | None known |
| Supportive interaction | None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Foods and Other Compounds
Food
Test tube studies show that watercress, garlic, tea, and cruciferous vegetables, such as Brussels sprouts, broccoli, and Chinese cabbage, block the breakdown of chlorzoxazone into inactive compounds.1 2 Controlled human research is needed to determine whether these interactions are important in people taking chlorzoxazone.
Alcohol
Drinking alcoholic beverages while taking chlorzoxazone may enhance side effects of the drug, such as drowsiness, dizziness, and light-headedness.3 In addition, test tube studies show that alcohol might increase the elimination of chlorzoxazone from the body.4 Consequently, people who are taking chlorzoxazone should avoid drinking alcohol.
Smoking
Studies show that cigarette smoking increases the elimination of chlorzoxazone from the body.5 Problems could occur if people either start or stop smoking while taking chlorzoxazone: individuals who stop smoking may experience increased side effects, while those who start smoking may notice that the drug is less effective.
Caffeine
Controlled studies show that chlorzoxazone reduces the elimination of caffeine from the body,6 which could cause side effects of caffeine, such as restlessness and insomnia. If side effects occur, some individuals may need to avoid caffeinated beverages, such as coffee and tea, while taking chlorzoxazone.
References
1. Walter-Sack I, Klotz U. Influence of diet and nutritional status on drug metabolism. Clin Pharmacokin 1996;31:47–64.
2. Marchand LL, Wilkinson GR, Wilkens LR. Genetic and dietary predictors of CYP2E1 activity: a phenotyping study in Hawaii Japanese using chlorzoxazone. Cancer Epidemiol Biomarkers Prev 1999;8:495–500.
3. Sifton DW, ed. Physicians Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 2200.
4. Klotz U, Ammon E. Clinical and toxicological consequences of the inductive potential of ethanol. Eur J Clin Pharmacol 1998;54:7–12.
5. Zevin S, Benowitz NC. Drug interactions with tobacco smoking. An update. Clin Pharmacokinet 1999;36:425–38.
6. Berthou F, Goasduff T, Lucas D, et al. Interaction between two probes used for phenotyping cytochromes P4501A2 (caffeine) and P4502E1 (chlorzoxazone) in humans. Pharmacogenetics 1995;5:72–9.
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2006-09-07
