Azithromycin absorption

Owing to interference by antacids, azithromycin should be given at least 1 hour before or 2 hours after antacids. Antacids containing aluminium and magnesium reduce peak serum concentrations, but the total extent of azithromycin absorption is not altered (45). 

Food appears to halve azithromycin absorption from the capsule formulation, but does not alter the AUC of tablets or suspension. 

Azithromycin is rapidly absorbed and well tolerated orally. It should be administered 1 hour before or 2 hours after meals. Aluminum and magnesium antacids do not alter bioavailability but delay absorption and reduce peak serum concentrations. Because it has a 15-member (not 14-member) lactone ring, azithromycin does not inactivate cytochrome P450 enzymes and therefore is free of the drug interactions that occur with erythromycin and clarithromycin. 

Administration The erythromycin base is destroyed by gastric acid thus either enteric coated tablets or esterified forms are administered. All are adequately absorbed on oral administration. Clarithromycin and azithromycin are stable to stomach acid and are readily absorbed. Food interferes with the absorption of erythromycin and azithromycin but can increase that of clarithromycin. Intravenous administration of erythromycin is associated with a high incidence of thrombophlebitis. 

CEFPODOXIME, CEFUROXIME ANTACIDS L levels of these antibiotics L absorption Take azithromycin at least 1 hour before or 2 hours after an antacid. Take these cephalosporins at least 2 hours after an antacid. Separate quinolones and antacids by 2-6 hours. Separate tetracyclines and antacids by 2-3 hours... 

AZITHROMYCIN MAGNESIUM 1 plasmafoody concentrations of magnesium Due to l absorption Be aware... 

They are also likely to reduce absorption of azithromycin, nitrofurantoin, rifampicin, phenytoin, chloroquine, phenothiazine antipsychotics and bisphosphonates. 

In 10 healthy subjects the peak serum levels, but not the total absorption, of azithromycin was reduced by 30 mL Maalox (alimiinium/magnesi-um hydroxide). It is suggested therefore that azithromycin should not be given at the same time as antacids, but should be taken at least 1 hour... 

Aluminium/magnesium hydroxide antacids may reduce the peak levels of azithromycin. Mylanta can prolong the absorption of erythromycin, but this is unlikely to be clinically important Aluminium/magnesium hydroxide antacids do not appear to significantly alter the pharmacokinetics of clarithromycin, roxithromycin or telithromycin. 

The pharmacokinetics of azithromycin were not affected by a single 800-mg dose of cimetidine in one study, and although cimetidine prolongs the absorption of clarithromycin, this is unlikely to be of clinical significance. ... 

A review by the manufacturers briefly mentions that food reduced the absorption of azithromycin by about half It is suggested therefore that azithromycin capsules should not be given at the same time as food, but should be taken at least 1 hour before or 2 hours after a meal. - However, the US prescribing information states that a high-fat meal increased the maximum levels of azithromycin tablets by 23%, and had no effect on the AUC. Similarly, food increased the maximum levels of azithromycin pension by 56%, without altering the AUC. Azithromycin suspension and tablets may therefore be taken without regard to food. 

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