Metampicillin

Oral
Susceptible infections

Hypersensitivity to penicillins.

Discontinue if skin rash occurs; risk increased in infectious mononucleosis, lymphatic leukaemia or possibly HIV-infected patients. Avoid large doses, especially in patients with renal impairment. Monitor renal, hepatic and haematological functions. Superinfection with penicillin-resistant organisms with prolonged use.

Skin rash (urticarial or maculopapular), diarrhoea, nausea, vomiting, pseudomembranous colitis.
Potentially Fatal: Anaphylaxis.

Antagonism with rifampicin (high penicillin concentration) or synergism with rifampicin (low penicillin concentration). May reduce serum concentration of sulfapyridine (metabolite of sulfasalazine). May decrease renal clearance of methotrexate. May reduce efficacy of oral contraceptives. Increased serum concentrations with probenecid. Increased risk of rash with allopurinol.

May interfere with tests for urinary glucose using copper sulfate, direct Coombs' test, and certain tests for urinary or serum proteins. May interfere with tests that use bacteria.

Description:
Mechanism of Action: Metampicillin, like other penicillins, exerts its bactericidal action by inhibiting bacterial cell wall synthesis. It has the same antibacterial spectrum as ampicillin.
Pharmacokinetics:
Distribution: Distributes in CSF.
Metabolism: Oral dose completely hydrolysed to ampicillin.
Excretion: High biliary excretion (IV).

Penicillins