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Oxacillin Side Effects

For the Consumer

Applies to oxacillin: parenteral injection, parenteral powder for injection

Side effects include:

Hypersensitivity reactions; local reactions (phlebitis, thrombophlebitis); renal, hepatic, or nervous system effects with high dosage.

For Healthcare Professionals

Applies to oxacillin: injectable powder for injection, intravenous solution, oral capsule, oral powder for reconstitution


Gastrointestinal side effects have included nausea, vomiting, diarrhea, stomatitis, black or hairy tongue, gastrointestinal irritation, and pseudomembranous colitis.[Ref]


Hematologic effects of oxacillin are uncommon and appear to be associated with higher doses given for prolonged periods. Oxacillin may exert a reversible toxic effect on the maturation of granulocytes. Some investigators have also suggested a possible hypersensitivity or immunologic component. Recovery generally occurs within several days to 2 weeks following discontinuation of therapy. Penicillin and some of its other semisynthetic derivatives are also associated with hematologic toxicities.[Ref]

Hematologic adverse effects have included neutropenia, leukopenia, thrombocytopenia, bone marrow depression, and agranulocytosis.[Ref]


Hepatic side effects have included cholestatic jaundice associated with the use of high parenteral doses. A case of severe hepatitis has also been reported. Alkaline phosphatase and GGT serum levels may take several weeks to return to normal following discontinuation of therapy.[Ref]

Serum liver enzyme levels have typically returned to normal soon after stopping therapy or changing to another antibiotic such as nafcillin, which is chemically related to oxacillin. Patients may be asymptomatic or have hepatic tenderness or enlargement and/or pronounced fever, nausea, and vomiting. Hepatotoxicity may also occur on a hypersensitivity basis and accompany some allergic manifestations such as pruritus, eosinophilia, and serum sickness.

Intravenous oxacillin has been associated with a higher incidence of hepatotoxicity than nafcillin, clindamycin, or other intravenous antimicrobials in children. The onset of hepatitis occurred after 6 to 43 days of oxacillin treatment (n=9).[Ref]


Hypersensitivity reactions have included urticaria, pruritus, angioneurotic edema, laryngospasm, bronchospasm, hypotension, vascular collapse, anaphylaxis, death, serum sickness-like reactions, fever, and rash.[Ref]


Local side effects of parenteral administration have included thrombophlebitis and tissue necrosis following extravasation.[Ref]


Renal side effects have included acute renal failure and interstitial nephritis.[Ref]

Nervous system

Nervous system side effects including seizures have occurred when large parenteral doses of oxacillin were administered to patients with renal failure.[Ref]


Metabolic side effects including severe hypokalemia, have been rarely associated with the use of high dose oxacillin (12 grams per day for 10 days).[Ref]


Intravenous oxacillin has been associated with a higher incidence of rash than nafcillin or other intravenous antimicrobials in children. The onset of rash occurred after a mean of 19.5 days of oxacillin treatment.[Ref]

Dermatologic side effects included hypersensitivity-related urticaria, pruritus, and rash.[Ref]


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2. Friedman RJ, Mayer IE, Galambos JT, Hersh T "Oxacillin-induced pseudomembranous colitis." Am J Gastroenterol 73 (1980): 445-7

3. Thomas E, Mehta JB "Pseudomembranous colitis due to oxacillin therapy." South Med J 77 (1984): 532-3

4. Fallon JA, Tall AR, Janis MG, Brauer MJ "Oxacillin-induced granulocytopenia." Acta Haematol 59 (1978): 163-70

5. Carpenter J "Neutropenia induced by semisynthetic penicillin." South Med J 73 (1980): 745-8

6. Chu JY, O'Connor DM, Schmidt RR "The mechanism of oxacillin-induced neutropenia." J Pediatr 90 (1977): 668-9

7. Slovick FT, Bamberger DM, Stark KR "Spontaneous clostridial myonecrosis in a man with drug-induced agranulocytosis." South Med J 82 (1989): 1272-4

8. Kahn JB "Oxacillin-induced agranulocytosis." JAMA 240 (1978): 2632

9. Leventhal JM, Silken AB "Oxacillin-induced neutropenia in children." J Pediatr 89 (1976): 769-71

10. Passoff TL, Sherry HS "Oxacillin induced neutropenia. A case report." Clin Orthop 135 (1978): 69-70

11. Brook I "Leukopenia and granulocytopenia after oxacillin therapy." South Med J 70 (1977): 565-6

12. Ahern MJ, Hicks JE, Andriole VT "Neutropenia during high dose intravenous oxacillin therapy." Yale J Biol Med 49 (1976): 351-60

13. Tauris P, Jorgensen NF, Petersen CM, Albertsen K "Prolonged severe cholestasis induced by oxacillin derivatives." Acta Med Scand 217 (1985): 567-9

14. Miller WI, Souney PF, Chang JT "Hepatic dysfunction following nafcillin and cephalothin therapy in a patient with a history of oxacillin hepatitis." Clin Pharm 2 (1983): 465-8

15. Dismukes WE "Oxacillin-induced hepatic dysfunction." JAMA 226 (1973): 861-3

16. Olans RN, Weiner LB "Reversible oxacillin hepatotoxicity." J Pediatr 89 (1976): 835-8

17. Maraqa NF, Gomez MM, Rathore MH, Alvarez AM "Higher occurrence of hepatotoxicity and rash in patients treated with oxacillin, compared with those treated with nafcillin and other commonly used antimicrobials." Clin Infect Dis 34 (2002): 50-4

18. Deboever G "Cholestatic jaundice due to derivatives of oxacillin." Am J Gastroenterol 82 (1987): 483

19. Halloran TJ, Clague MD "Hepatitis associated with high-dose oxacillin therapy." Arch Intern Med 139 (1979): 376-7

20. Trevenzoli M, Cattelan AM, Mencarelli R, Meneghetti F "Severe hepatitis associated with oxacillin therapy." South Med J 96 (2003): 324-5

21. "Product Information. Bactocill (oxacillin)." SmithKline Beecham, Philadelphia, PA.

22. Fromm LA, Graham DL "Oxacillin-induced tissue necrosis." Ann Pharmacother 33 (1999): 1060-2

23. Tillman DB, Oill PA, Guze LB "Oxacillin nephritis." Arch Intern Med 140 (1980): 1552

24. Schlaeffer F "Oxacillin-associated hypokalemia." Drug Intell Clin Pharm 22 (1988): 695-6

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.