nafcillin sodium /nafsil″in/ , an antibiotic. 
INDICATIONS: It is prescribed in the treatment of infections caused by penicillinase-producing staphylococci. CONTRAINDICATIONS: Known hypersensitivity to this drug or to other penicillins prohibits its use. ADVERSE EFFECTS: Among the more serious adverse effects are hypersensitivity reactions, nausea, and vomiting.
