Dosing and uses of Nafcil, Nallpen (nafcillin)
Adult dosage forms and strengths
injectable solution
- 20mg/mL
- 2g/100mL
powder for injection
- 1g
- 2g
- 10g
Susceptible Infections
500 mg IV/IM q4-6hr
Severe Infections
1 g IV/IM q4hr
Staphylococcal Endocarditis
2 g IV q4hr for 4-6 weeks; may be longer and may add rifampin and gentamicin if prosthetics present
Bursitis septic
2 g IV q4hr
Administration
Initial therapy for suspected penicillin G-resistant streptococcal or staphylococcal infections.
Use parenteral therapy initially in severe infections.
Change to oral therapy as condition warrants. Due to thrombophlebitis, particularly in the elderly, administer parenterally only for short term (1-2 d); change to oral route as clinically indicated.
Renal Impairment
Dose adjustment not necessary unless concomitant hepatic failure present
Hepatic Impairment
Dose adjustment not necessary unless concomitant renal failure present
Pediatric dosage forms and strengths
injectable solution
- 20mg/mL
- 2g/100mL
powder for injection
- 1g
- 2g
- 10g
Susceptible Infections
50-100 mg/kg/day IV/IM divided q6hr
Maximum 12g/day
Severe Infections
100-200 mg/kg/day IV/IM divided q6hr
Staphylococcal Endocarditis
200mg/kg/day IV divided q4-6hr for 6 weeks; may be longer and may add rifampin and gentamicin if prosthetics present
Neonates (<28 Days Old)
(<7 days old, <2 kg) OR (>7 days old, <1.2 kg): 50 mg/kg/day IV/IM divided q12hr
(<7 days old, >2 kg) OR (>7 days old, 1.2-2 kg): 75 mg/kg/day IV/IM divided q8hr
(>7 days old, >2 kg): 100-140 mg/kg/day IV/IM divided q6hr
Nafcil, Nallpen (nafcillin) adverse (side) effects
1-10%
Hypersensitivity
Neutropenia
Interstitial nephritis
Possible hypokalemia
<1%
Neurotoxicity (high doses)
Pseudomembranous colitis
Phlebitis (oxacillin preferred in peds)
Warnings
Contraindications
A history of a hypersensitivity (anaphylactic) reaction to any penicillin
Solutions containing dextrose in patients with known allergy to corn or corn products
Cautions
Evaluate renal, hepatic, hematologic systems periodically during prolonged treatment
Serious and occasionally fatal hypersensitivity (anaphylactic) reactions reported; reactions are more likely to occur in individuals with history of penicillin hypersensitivity and/or a history of sensitivity to multiple allergens; inquire about previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens before initiating therapy; if allergic reaction occurs, discontinue treatment and institute appropriate therapy
If clostridium difficile associated diarrhea (CDAD) suspected or confirmed, may need to discontinue ongoing antibiotic use not directed against C. difficile; appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated
The use of antibiotics may result in overgrowth of nonsusceptible organisms; if new infections due to bacteria or fungi occur, discontinue drug and take appropriate measures
To optimize therapy, determine causative organisms and susceptibility; > 10 d treatment to eliminate infection and prevent sequelae (eg, endocarditis, rheumatic fever); take cultures after treatment to confirm that infection is eradicated
Pregnancy and lactation
Pregnancy category: B
Lactation: Excreted into breast milk; use caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Nafcil, Nallpen (nafcillin)
Mechanism of action
Inhibit synthesis of bacterial cell wall synthesis, which results in bactericidal activity
Pharmacokinetics
Half-Life: 0.5-1.5 hr (adults); 0.75-1.9 hr (children)
Peak Plasma Time: 0.5-1 hr
Protein binding: 90%
Absorption: Poorly absorbed orally
Distribution: In fluid, bone, bile, crosses placenta
Vd: 0.5-1.5 L/kg
Metabolism: Liver
Excretion: Liver (primarily), renal (10-30%)
Enzymes induced: Hepatic CYP3A4
Administration
IV Incompatibilities
Additive: aminophylline(?), ascorbic acid, aztreonam, bleomycin, cytarabine, gentamicin, hydrocortisone sodium succinate, methylprednisolone sodium succinate, promazine, vit B/C(?)
Y-site: diltiazem(?), droperidol, insulin (regular), labetalol, meperidine(?), midazolam, nalbuphine, pentazocine, vancomycin(?), verapamiL
IV Compatibilities
Solution: compatible w/ most common solvents
Additive (partial list): dexamethasone sodium phosphate, diphenhydramine, heparin, lidocaine, KCl, prochlorperazine, Na bicarB
Syringe: cimetidine, heparin
Y-site (partial list): acyclovir, atropine, diazepam, fentanyl, fluconazole, heparin, MgSO4, morphine, propofol, zidovudine
IV/IM Preparation
IM/IV: reconstitute 1-2 g of drug w/ 3.4- 6.8 mL SWI/BWI/NS to 250 mg/mL
IV inj: further dilute w/ 15-30 mL SWI/Ns
IV infusion: further dilute w/ IV solution according to Mfr's directions
Bulk Packages:
- Reconstitute 10 g of drug w/ 93 mL SWI/NS to 100 mg/mL
- THEN further dilute before administration
- Not for direct IV injection
IV/IM Administration
IM: deep into large muscle
IV inj: slowly over 5-10 min
IV infusion: over at least 30-60 min
