Nafcillin
Mechanism :
It is semisynthetic penicillinase resistant penicillin used primarily in the treatment of staphylococcal infections.
Indication :
- Treatment of infections caused by penicillinase producing staphylococci
Contraindications :
Hypersensitivity or anaphylactic reaction to beta lactams.
Caution in seizure disorder, asthma, sodium restriction, renal or hepatic impairment.
Dosing :
Susceptible infections:
50-100 mg/kg/day IV/IM in 4 divided doses.
Severe infections:
100-200 mg/kg/day IV/IM in 4 divided doses.
Staphylococcal endocarditis:
200 mg/kg/day IV in 4-6 divided doses for 6 weeks.
Neonates (<7 days, <2 kg) OR (>7 days, <1.2 kg):
50 mg/kg/day IV/IM in 2 divided doses.
Neonates (<7 days, >2 kg) OR (>7 days, 1.2-2 kg):
75 mg/kg/day IV/IM in 3 divided doses.
Neonates (<7 days, >2 kg):
100-140 mg/kg/day IV/IM in 4 divided doses.
Adverse Effect :
Hypersensitivity, granulocytopenia and nephrotoxicity (interstitial nephritis), hypokalemia.
Interaction :
Cyclosporine: Nafcillin alters serum levels of cyclosporine.
Demeclocycline: Possible antagonism of action.
Doxycycline: Possible antagonism of action.
Estradiol valerate/Dienogest: Affects CYP3A4 metabolism, decreases or effects levels of Estradiol valerate/Dienogest.
Ethinyl Estradiol: This anti-infectious agent could decrease the effect of the oral contraceptive.
Lurasidone: Concomitant therapy will decrease levels of lurasidone via effects on CYP 3A4. Concomitant therapy is contraindicated.
Methotrexate: The penicillin increases the effect and toxicity of methotrexate.
Minocycline: Possible antagonism of action.
Roflumilast: Affects CYP3A4 metabolism, decreases level or effect of roflumilast.
Telithromycin: Nafcillin may decrease the plasma concentration of Telithromycin. Consider alternate therapy.
Temsirolimus: Nafcillin may increase the metabolism of Temsirolimus decreasing its efficacy. Concomitant therapy should be avoided.
Tetracycline: Possible antagonism of action.
Tramadol: Nafcillin may decrease the effect of Tramadol by increasing Tramadol metabolism and clearance.
Trazodone: The CYP3A4 inducer, Nafcillin, may decrease Trazodone efficacy by increasing Trazodone metabolism and clearance. Monitor for changes in Trazodone efficacy/toxicity if Nafcillin is initiated, discontinued or dose changed.
Vandetanib: Decreases levels of vandetanib by affecting CYP3A4 metabolism. Contraindicated.
Verapamil: Nafcillin may decrease the serum concentration of Verapamil by increasing its metabolism via CYP3A4. Monitor for changes in the therapeutic/adverse effects of Verapamil if Nafcillin is initiated, discontinued or dose changed.
Warfarin: Nafcillin may increase the anticoagulant effect of warfarin increasing the risk of bleeding. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of warfarin if nafcillin is initiated, discontinued or dose changed.
Hepatic Dose :
Nafcillin clearance is significantly decreased in patients with hepatic dysfunction. Use with caution. No dose adjustments are recommended.