Basic Information
ID DDInter598 and DDInter2188
Interaction The bioavailability of oral tetracyclines and iron salts may be significantly decreased during concurrent administration. Therapeutic failure may result. The proposed mechanism is chelation of tetracyclines by the iron cation, forming an insoluble complex that is poorly absorbed from the gastrointestinal tract.
Management Coadministration of a tetracycline with any iron-containing product should be avoided if possible. Otherwise, patients should be advised to stagger the times of administration by at least three to four hours, although separating the doses may not prevent the interaction with doxycycline.
References [1] Neuvonen PJ "Interactions with the absorption of tetracyclines." Drugs 11 (1976): 45-54 [2] Gothoni G, Neuvonen PJ, Mattila M, Hackman R "Iron-tetracycline interaction: effect of time interval between the drugs." Acta Med Scand 191 (1972): 409-11 [3] Venho VM, Salonen RO, Mattila MJ "Modification of the pharmacokinetics of doxycycline in man by ferrous sulphate or charcoal." Eur J Clin Pharmacol 14 (1978): 277-80 [4] "Product Information. Minocin (minocycline)." Lederle Laboratories (2002): [5] Campbell NR, Hasinoff BB "Iron supplements: a common cause of drug interactions." Br J Clin Pharmacol 31 (1991): 251-5 [6] Bateman FJ "Effects of tetracyclines." Br Med J 4 (1970): 802 [7] Neuvonen PJ, Gothoni G, Hackman R, Bjorksten K "Interference of iron with the absorption of tetracyclines in man." Br Med J 4 (1970): 532-4 [8] Greenberger NJ "Absorption of tetracyclines: interference by iron." Ann Intern Med 74 (1971): 792-3 [9] Neuvonen PJ, Penttila O "Effect of oral ferrous sulphate on the half-life of doxycycline in man." Eur J Clin Pharmacol 7 (1974): 361-3 [10] "Product Information. Seysara (sarecycline)." Allergan Inc (2018): [11] "Product Information. Nuzyra (omadacycline)." Paratek Pharmaceuticals, Inc. (2018):
Alternative for Doxycycline J01A
Eravacycline Tigecycline

A01A
Prednisolone Miconazole Triamcinolone Acetylsalicylic acid Dexamethasone Epinephrine
Amphotericin B Hydrocortisone Chlorhexidine
More
Alternative for Iron (polysaccharide) -
Potential Metabolism Interactions
Substrate-Substrate Interaction：If more than one drug is metabolized by the same CYP, it is possible that its metabolism is inhibited because of the competition between the drugs. That means, it can be useful to lower the dosage of the drugs in the drug-cocktail because they remain longer in the organism than in monotherapy.
Inhibitor-Inhibitor Interaction：Combining two or more inhibitors of one CYP, should be compensated by lowering the dosage of these drugs because the metabolism is reduced and the drugs remain longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.
Inhibitor-Substrate Interaction：Combining drugs that have inhibitory effect and are substrates of one particular CYP, should be compensated by lowering the dosage. They rest longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.