Tetracyclines (drug interactions)
Tetracyclines are a class of antibiotics commonly used to treat various infections, including chlamydia, and for the long-term management of acne. However, they can interact with several substances, which may affect their efficacy or lead to harmful effects. Notably, minerals like aluminum, calcium, and iron can hinder the absorption of tetracyclines, so it is advisable to take these supplements at least two hours before or after consuming tetracycline medications. Herbal supplements such as St. John's wort and dong quai may also increase the risk of sun sensitivity when taken concurrently with tetracyclines, necessitating precautions like sunscreen use.
Additionally, citrate supplements can reduce the effectiveness of tetracycline antibiotics by altering urinary acidity. Interactions with anticoagulants, multivitamins, and certain medications for conditions like lupus or kidney disease may pose further risks. Pregnant women are advised against using tetracycline antibiotics due to potential harm to the fetus. Overall, awareness of these interactions is crucial for anyone considering or currently using tetracycline medications to ensure safe and effective treatment.
Tetracyclines (drug interactions)
DEFINITION: Antibiotics used to treat certain infections, such as chlamydia, and for long-term treatment of acne.
INTERACTIONS: Citrate, dong quai, minerals, St. John’s wort, milk thistle, various prescription medications
DRUGS IN THIS FAMILY: Doxycycline (Doryx, Monodox, Vibramycin), minocycline hydrochloride (Minocin)
Minerals
Effect: Take at a Different Time of Day
Numerous minerals, including aluminum (found in many antacids), bismuth (in Pepto-Bismol), calcium, iron, magnesium, and zinc, interfere with the absorption of medications in the tetracycline family (and vice versa). The minerals and the drugs attach to each other, forming insoluble chemicals that simply pass out of the digestive tract. The best solution is to avoid taking supplements that contain these minerals within the two hours before or after taking a tetracycline medication.
Dong Quai, St. John’s Wort
Effect: Possible Harmful Interaction
Tetracycline antibiotics have been reported to cause increased sensitivity to the sun, amplifying the risk of sunburn or skin rash. Because St. John’s wort and dong quai may also cause this problem, taking these herbal supplements during tetracycline treatment might add to this risk. People should wear sunscreen or protective clothing during sun exposure if they take one of these herbs with a tetracycline antibiotic.
Citrate
Effect: Possible Harmful Interaction
Potassium citrate, sodium citrate, and potassium-magnesium citrate are sometimes used to prevent kidney stones. These supplements reduce urinary acidity, which can, therefore, decrease blood levels and the effectiveness of tetracycline antibiotics.
Other Interactions
Tetracycline antibiotics react with many other medications, and these reactions can range from major to minor. Patients taking anticoagulants like warfarin or penicillin should not take tetracycline antibiotics. Multivitamins and milk products may make the antibiotics less effective and should be avoided within two hours of taking the dose. If a patient has lupus or kidney disease and is taking medication for those conditions, tetracycline antibiotics should also be avoided. Milk thistle may potentially alter liver enzymes and, in turn, alter the effectiveness of tetracycline antibiotics. Taking tetracycline antibiotics with retinoids can increase the risk of intracranial hypertension. People taking tetracycline antibiotics should avoid using methoxyflurane as an anesthetic, as it can cause live and kidney toxicity. Women who are pregnant should not use tetracycline antibiotics as they will harm the fetus.
Bibliography
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Ohnishi, M., et al. "Effect of a Kampo Preparation, Byakkokaninjinto, on Pharmacokinetics of Ciprofloxacin and Tetracycline." Biological and Pharmaceutical Bulletin, vol. 32, 2009, pp. 1080-1084.
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Thappa, D. M., and J. Dogra. "Nodulocystic Acne: Oral Gugulipid Versus Tetracycline." Journal of Dermatology, vol. 21, 1994, pp. 729-731.