Nafcillin sodium dosage and administration
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohamed Moubarak, M.D. [2]
Dosage and Administration
Nafcillin for injection Pharmacy Bulk Package is available for intravenous use only. The usual I.V. dosage for adults is 500 mg every 4 hours. For severe infections, 1 gram every 4 hours is recommended. Administer slowly over at least 30 to 60 minutes to minimize the risk of vein irritation and extravasation.
Bacteriologic studies to determine the causative organisms and their susceptibility to nafcillin should always be performed. Duration of therapy varies with the type and severity of infection as well as the overall condition of the patient; therefore, it should be determined by the clinical and bacteriological response of the patient. In severe staphylococcal infections, therapy with nafcillin should be continued for at least 14 days. Therapy should be continued for at least 48 hours after the patient has become afebrile, asymptomatic, and cultures are negative. The treatment of endocarditis and osteomyelitis may require a longer duration of therapy.
Concurrent administration of the penicillinase-resistant penicillins and probenecid increases and prolongs serum penicillin levels. Probenecid decreases the apparent volume of distribution and slows the rate of excretion by competitively inhibiting renal tubular secretion of penicillin. Nafcillin-probenecid therapy is generally limited to those infections where very high serum levels of nafcillin are necessary.
No dosage alterations are necessary of patients with renal dysfunction, including those on hemodialysis. Hemodialysis does not accelerate nafcillin clearance from the blood.
For patients with hepatic insufficiency and renal failure, measurement of nafcillin serum levels should be performed and dosage adjusted accordingly.
With intravenous administration, particularly in elderly patients, care should be taken because of the possibility of thrombophlebitis.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.
Do not add supplementary medication to nafcillin.
Oral preparation of the penicillinase-resistant penicillins should not be used as initial therapy in serious life-threatening infections (see PRECAUTIONS, General). Oral therapy with the penicillinase-resistant penicillins may be used to follow-up the previous use of a parenteral agent as soon as the clinical condition warrants. With intravenous administration, particularly in elderly patients, care should be taken because of the possibility of thrombophlebitis.[1]
References
Adapted from the FDA Package Insert.