Does antacid use reduce tigecycline absorption?
Tigecycline, an intravenous glycylcycline antibiotic, shows no clinically significant change in bioavailability when co-administered with antacids. A randomized crossover study in 26 healthy adults found that a single 100 mg dose of tigecycline given with Maalox (aluminum/magnesium hydroxide antacid) produced similar peak plasma concentrations (Cmax) and area under the curve (AUC) compared to tigecycline alone. Cmax decreased by only 9% (geometric mean ratio 0.91, 90% CI 0.80-1.04), and AUC_0-∞ by 8% (ratio 0.92, 90% CI 0.83-1.02).[1][2]
Why don't antacids impact tigecycline like other tetracyclines?
Unlike oral tetracyclines (e.g., doxycycline), which form chelates with antacid cations like aluminum, magnesium, or calcium that impair gut absorption, tigecycline is given IV and bypasses gastrointestinal factors. Its primary elimination is biliary/fecal (59%), with minimal renal clearance (22%), so antacid-related pH changes or ion binding do not affect systemic exposure.[1][3]
What about other acid reducers like PPIs or H2 blockers?
No specific interaction data exists for proton pump inhibitors (e.g., omeprazole) or H2 blockers (e.g., ranitidine) with tigecycline. Labeling notes potential minor effects from multivalent cations in general, but clinical studies confirm antacids are safe to use concurrently without dose adjustments.[2][4]
Clinical recommendations for tigecycline dosing with antacids
Administer tigecycline IV over 30-60 minutes without separation from antacids. No dose modification is needed. Monitor for tigecycline's common risks like nausea (26%) or superinfections, unrelated to antacids.[2][5]
Sources
[1] Tigecycline prescribing information, FDA label
[2] Mylan-Tigecycline product monograph
[3] Clinical pharmacology review, NDA 21-821
[4] Drug interactions database, Lexicomp
[5] Tygacil summary of product characteristics, EMA