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nafcillin (naf-sil-in)

Nallpen, Unipen


Therapeutic: anti-infectives

Pharmacologic: penicillinase-resistant penicillins


Treatment of the following infections due to penicillinase-producing staphylococci: Respiratory tract infections; Sinusitis; Skin and skin structure infections; Bone and joint infections; Urinary tract infections; Endocarditis; Bacteremia; Meningitis.


Bind to bacterial cell wall, leading to cell death. Not inactivated by penicillinase enzymes. Therapeutic Effects: Bactericidal action. Spectrum: Active against most gram-positive aerobic cocci. Spectrum is notable for activity against Penicillinase-producing strains of Staphylococcus aureus, S. epidermidis. Not active against methicillin-resistant bacteria.

Adverse Reactions/Side Effects

CNS: SEIZURES. GI: PSEUDOMEMBRANOUS COLITIS, diarrhea, epigastric distress, nausea, vomiting. GU: interstitial nephritis. Derm: rash, urticaria. Hemat: eosinophilia, leukopenia. Local: pain at IM site, phlebitis at IV site. Misc: ALLERGIC REACTIONS, INCLUDING ANAPHYLAXIS AND SERUM SICKNESS, superinfection.


Examination and Evaluation

  • Watch for seizures; notify physician immediately if patient develops or increases seizure activity.

  • Monitor signs of pseudomembranous colitis, including diarrhea, abdominal pain, fever, pus or mucus in stools, and other severe or prolonged GI problems (nausea, vomiting, heartburn). Notify physician or nursing staff immediately of these signs.

  • Monitor signs of allergic reactions and anaphylaxis, including pulmonary symptoms (tightness in the throat and chest, wheezing, cough dyspnea) or skin reactions (rash, pruritus, urticaria). Notify physician or nursing staff immediately if these reactions occur.

  • Assess muscle aches and joint pain (arthralgia) that may be caused by serum sickness. Notify physician if these symptoms seem to be drug-related rather than caused by musculoskeletal injury or if muscle and joint pain are accompanied by allergy-like reactions (fever, rashes, etc.)

  • Monitor signs of eosinophilia (fatigue, weakness, myalgia) or leukopenia (fever, sore throat, signs of infection); report these signs to the physician.

  • Monitor injection site for pain, swelling, and irritation. Report prolonged or excessive injection-site reactions to the physician or nursing staff.


  • Always wash hands thoroughly and disinfect equipment (whirlpools, electrotherapeutic devices, treatment tables, and so forth) to help prevent the spread of infection. Use universal precautions or isolation procedures as indicated for specific patients.

Patient/Client-Related Instruction

  • Instruct patient to notify physician immediately if signs of the following occur:

    • ∘ Superinfection (black, furry overgrowth on tongue; vaginal itching or discharge; loose or foul-smelling stools).

    • ∘ Interstitial nephritis (blood in urine, decreased urine output, weight gain from fluid retention).

  • Instruct patient and family/caregivers to report other troublesome side effects such as severe or prolonged skin problems (rash, itching) or GI problems (nausea, vomiting, diarrhea, heartburn).


Absorption: Completely absorbed following IV administration; well absorbed from IM sites.

Distribution: Widely distributed; penetration into CSF is ...

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