Aluminium/magnesium hydroxide and aluminium hydroxide donot significantly affect bioavailability of amoxicillin or amoxicillin with clavulanic acid (co-amoxiclav). Antacids may reducethe absorption of hydrochloride salt of pivampicillin
Clinical evidence,mechanism, importance and management
The pharmacokinetics of amoxicillin 1 g, and both amoxicillin and clavulanic acid (given as co-amoxiclav 625 mg), were not significantly altered by 10 doses of aluminium/magnesium hydroxide (Maalox) 10 mL, with last dose given 30 minutes before amoxicillin (See reference number 1). Another study found that four 40mg doses of aluminium hydroxide (Aludrox) given at 20 minute intervals had no effect on pharmacokinetics of either amoxicillin or clavulanic acid (given as co-amoxiclav 750mg with second dose of antacid) (See reference number 2).
There would seem to be no reason for avoiding concurrent use of antacids and amoxicillin or co-amoxiclav
The UK manufacturers(See reference number 3)used to recommend that,because antacids may decrease pivampicillin absorption, concurrent use should be avoided. This warning relates to a hydrochloride salt formulation, which needs acidic conditions for optimal absorption, whereas basic salt formulation should not be affected by any pH change (See reference number 4).
Deppermann K-M,Lode H, Höffken G, Tschink G, Kalz C, Koeppe P. Influence of ranitidine,pirenzepine, and aluminium magnesium hydroxide on the bioavailability of various antibacterials, including amoxicillin, cephalexin, doxycycline, and amoxicillin-clavulanic acid. Antimicrob Agents Chemother (1989) 33, 1901–7.
Staniforth DH,Clarke HL, Horton R, Jackson D, Lau D. Augmentin bioavailability followingcimetidine, aluminum hydroxide and milk. Int J Clin Pharmacol Ther Toxicol (1985) 23, 145–
7.
Pondocillin (Pivampicillin). Leo Laboratories Ltd. ABPI Compendium of Datasheets andSummaries of Product Characteristics,1998–99, 625–6.
Leo Laboratories Limited. Personal communication,March 1995.