Applies to nafcillin: 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 nafcillin: injectable powder for injection, intravenous solution, oral capsule.

Hypersensitivity

Common (1% to 10%): Allergic reactions (included immediate and delayed reactions)

Very rare (less than 0.01%): Anaphylactic shock resulting in death

Frequency not reported: Immediate allergic reaction (included urticaria, pruritus, angioedema, laryngospasm, bronchospasm, hypotension, vascular collapse, death), anaphylaxis, accelerated immediate allergic reaction (included urticaria, pruritus, fever, laryngeal edema, laryngospasm, hypotension), delayed allergic reaction (included serum sickness-like reactions [i.e., fever, malaise, urticaria, myalgia, arthralgia, abdominal pain], various skin rashes)^[Ref]

Immediate allergic reactions usually occurred within 20 minutes of administration and ranged in severity from urticaria and pruritus to angioedema, laryngospasm, bronchospasm, hypotension, vascular collapse, and death; such immediate anaphylactic reactions were very rare and usually occurred after parenteral therapy but have occurred with oral therapy. An accelerated immediate allergic reaction has occurred between 20 minutes and 48 hours after administration and has included urticaria, pruritus, and fever; although laryngeal edema, laryngospasm, and hypotension occasionally occurred, fatality was uncommon.

Delayed allergic reactions to penicillin therapy usually occurred after 48 hours and sometimes as late as 2 to 4 weeks after starting therapy. Manifestations of this reaction included serum sickness-like symptoms (i.e., fever, malaise, urticaria, myalgia, arthralgia, abdominal pain) and various skin rashes.^[Ref]

Dermatologic

Frequency not reported: Rash, urticaria, pruritus^[Ref]

Gastrointestinal

Nausea, vomiting, diarrhea, stomatitis, black or hairy tongue, and gastrointestinal irritation have occurred, especially during oral penicillin therapy.

Onset of pseudomembranous colitis symptoms have occurred during and after antibiotic therapy.^[Ref]

Frequency not reported: Nausea, vomiting, diarrhea, stomatitis, black or hairy tongue, gastrointestinal irritation, pseudomembranous colitis, Clostridium difficile-associated diarrhea^[Ref]

Hematologic

Frequency not reported: Agranulocytosis, neutropenia, bone marrow depression, eosinophilia, platelet dysfunction (with prolonged bleeding times)^[Ref]

At least 3 cases of platelet dysfunction with prolonged bleeding times have been reported with this drug. All cases resolved after this drug was discontinued.^[Ref]

Hepatic

Elevated liver transaminases and cholestasis have been reported, especially with high doses.^[Ref]

Frequency not reported: Elevated liver transaminases, cholestasis, hepatotoxicity^[Ref]

Local

Frequency not reported: IV injection site pain, IV injection site swelling, IV injection site inflammation, IV injection site phlebitis, IV injection site thrombophlebitis, skin sloughing at IV injection site, severe tissue necrosis with sloughing (secondary to subcutaneous extravasation), pain at IM injection site^[Ref]

Nervous system

Frequency not reported: Neurotoxic reactions, neurotoxicity^[Ref]

Neurotoxic reactions (similar to those observed with penicillin G) have occurred with large IV or intraventricular doses, especially in patients with concurrent liver and renal dysfunction.^[Ref]

Other

Frequency not reported: Fever^[Ref]

Renal

Frequency not reported: Renal tubular damage, interstitial nephritis, nephrotoxicity (included rash, fever, eosinophilia, hematuria, proteinuria, acute kidney injury, renal insufficiency)^[Ref]

Genitourinary

Frequency not reported: Hematuria, proteinuria^[Ref]