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Pronunciation: naff-SILL-in SO-dee-uhm
Class: Penicillinase-resistant penicillin
- Injection 1 g (as base)
- Injection 2 g (as base)
Inhibits bacterial cell wall mucopeptide synthesis.
T max is 0.5 to 1 h.
Nafcillin is widely distributed in various body fluids (eg, bile, pleural, amniotic, synovial) and has high CSF penetration in presence of inflamed meninges. Protein binding is 89.9%, mainly albumin.
Nafcillin is metabolized mainly in the liver.
Nafcillin is excreted in urine (30% as unchanged), and primarily eliminated in bile. Serum t ½ is 33 to 61 min (IV).
Special PopulationsBiliary obstruction and cirrhosis
Plasma clearance is significantly decreased and excretion in urine was significantly increased from approximately 30% to 50%.
Indications and Usage
Treatment of infections caused by penicillinase-producing staphylococci.
Dosage and AdministrationAdults
IV Usual, 500 mg every 4 h. Severe infections, 1 g every 4 h. Infuse over at least 30 to 60 min.
- For IV administration only. Do not administer intradermal, SC, or IM.
- Thaw frozen container at room temperature (77°F) or under refrigeration (41°F). Do not force thawing by immersion in water or by microwave irradiation.
- Check thawed IV container for minute leaks by squeezing bag firmly. If leaks are detected discard solution because sterility may be impaired.
- Agitate thawed IV container and inspect visually. Do not administer if thawed solution is cloudy, discolored, or contains particulate matter or if any seal or outlet port is not intact.
- Do not add other medications to IV container.
Store IV bag in freezer at −4°F. Thawed solutions are stable for 21 days under refrigeration (41°F) or for 72 h at room temperature (77°F). Do not refreeze thawed solutions.
May reduce blood levels of cyclosporine.Disulfiram
May increase nafcillin levels.Probenecid
May increase nafcillin levels.Tetracycline
May reduce effectiveness of nafcillin.Warfarin
May increase warfarin effects.
Laboratory Test Interactions
May cause false-positive urine reaction for protein when the sulfosalicylic acid test is used.
Renal tubular damage; interstitial nephritis.
Immediate hypersensitivity reactions including urticaria; pruritus; angioneurotic edema; laryngospasm; bronchospasm; hypotension; vascular collapse. Delayed reactions including fever, malaise, urticaria, myalgia, arthralgia, abdominal pain, and rashes.
Agranulocytosis; neutropenia; bone marrow depression.
Local reactions include pain, swelling, phlebitis, thrombophlebitis, inflammation at the injection site.
Category B .
Secreted into breast milk.
Excretion may be impaired in newborns. Not approved for IV use in neonates or children.
Use with caution in patients with histories of significant allergies to penicillins or asthma.
May reduce nafcillin elimination.
May reduce nafcillin elimination.
May result in overgrowth of nonsusceptible organisms.
- Explain to patient or caregiver that medication is usually prepared and administered by a health care provider in a health care setting but may be used at home in some situations if ordered by the patient's health care provider.
- If patient or caregiver is administering at home ensure that the patient or caregiver understands how to store, prepare and administer the dose, and dispose of used equipment and supplies. The first injection should be performed under the supervision of a qualified health professional.
- Review dosing schedule and prescribed length of therapy with patient. Advise patient that dose and duration of therapy are dependent on site and cause of infection and response to therapy.
- Instruct patient to report the following to health care provider: itching; rash; hives; difficulty breathing; diarrhea; loose, foul-smelling stools; injection site reaction.
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