Nafcillin sodium is an beta-lactam antibiotic related to penicillin. As a beta-lactamase-resistant penicillin, it is used to treat infections caused by Gram-positive bacteria, particularly species of Staphylococci, that are resistant to other penicillins.

Administration

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Nafcillin can be given either orally (Unipen®) or by injection (Nallpen®)

Side effects

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As with all penicillins, serious life-threatening allergic reactions can occur.

Milder side effects include:

• Nausea and vomiting
• Diarrhea, often due to suppression of normal gastrointestinal bacteria. Occasionally, this leads to a more serious super-infection with an organism like Clostridium difficile
• Abdominal pain
• Yeast infections (thrush) affecting the mouth and tongue or vagina

Beta-lactam antibiotics