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Methicillin Side Effects

Applies to methicillin: injectable powder for injection


Adverse hematologic effects occur in approximately 7% of treated patients and appear to be associated with higher doses given for long periods of time. Recovery generally occurs within one to two weeks.[Ref]

Hematologic adverse effects reported with methicillin include neutropenia, leukopenia, and thrombocytopenia. Agranulocytosis has been reported rarely.[Ref]


Methicillin therapy has resulted in transient increases in liver function tests.[Ref]


Hypersensitivity reactions to methicillin include rash (2% to 6%), eosinophilia (up to 38%), pruritus, fever, chills, and myalgias. Methicillin is contraindicated in patients who are allergic to penicillin.[Ref]


Local reactions include thrombophlebitis associated with intravenous administration, and pain at injection site if given intramuscularly.[Ref]


Acute renal failure and interstitial nephritis have been associated with methicillin therapy. These problems occur most frequently after prolonged therapy (longer than ten days). Acute interstitial nephritis may be accompanied by rash, fever, dysuria, proteinuria, eosinophilia, and hematuria.[Ref]

The frequency of acute interstitial nephritis is higher with methicillin than other penicillinase-resistant penicillins and has been reported in up to 17% of patients. Acute renal failure generally occurs after ten days and with doses of methicillin greater than 200 mg/kg/day. Renal function slowly returns towards normal after discontinuation of methicillin, but irreversible decreases in renal function have been observed.[Ref]


1. Godin M, Deshayes P, Ducastelle T, Delpech A, Leloet X, Fillastre JP "Agranulocytosis, haemorrhagic cystitis and acute interstitial nephritis during methicillin therapy." J Antimicrob Chemother 6 (1980): 296-7

2. "Product Information. Staphcillin (methicillin)." Apothecon Inc, Plainsboro, NJ.

3. Mayaud C, Kanfer A, Kourilsky O, Sraer JD "Interstitial nephritis after methicillin." N Engl J Med 292 (1975): 1132-3

4. Mignon F, Mery JP, Mougenot B, Ronco P, Roland J, Morel-Maroger L "Granulomatous interstitial nephritis." Adv Nephrol Necker Hosp 13 (1984): 219-45

5. Linton AL, Clark WF, Driedger AA, Turnbull DI, Lindsay RM "Acute interstitial nephritis due to drugs." Ann Intern Med 93 (1980): 735-41

Some side effects of methicillin may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

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