Nitrofurantoin
General
- Type: Antibiotic
- Dosage Forms: oral
- Common Trade Names: Macrobid
Adult Dosing
Cystitis, acute uncomplicated or acute simple:[1]
- Monohydrate/macrocrystals (Macrobid): 100mg PO q12h
- Macrocrystals: 50-100mg PO 4 times daily for 5 days
Cystitis, recurrent, prophylaxis (continuous):[2]
- Monohydrate/macrocrystals (Macrobid): 100mg PO daily at bedtime
- Macrocrystals: 50-100mg PO daily at bedtime
Cystitis, postcoital prophylaxis
- Monohydrate/macrocrystals (Macrobid): 100mg PO once within 2 hours of sexual intercourse
- Macrocrystals: 50-100mg PO once within 2 hours of sexual intercourse
Pediatric Dosing
- >12yo: same as adult dosing
Special Populations
- Pregnancy Rating: B
- Lactation Risk: Infant risk minimal
- Renal Dosing: Contraindicated if CrCl <60
- Hepatic dosing:
Contraindications
- Allergy to class/drug
- Neonates, pregnant women at term or when delivery imminent
- Renal failure due to accumulation of metabolites that may cause peripheral neuropathy[3]
- CrCL < 60, oliguria, anuria
- Cholestatic jaundice history
Adverse Reactions
Serious
- Hemolytic anemia can occur in patients with G6PD deficiency and in infants less than 1 month old
- Hepatic necrosis
- Hepatitis
- Cholestatic jaundice syndrome
- Erythema multiforme/SJS
- Pancreatitis
- Peripheral neuropathy
- Pulmonary hypersensitivity
- Agranulocytosis
- Leukopenia
- Thrombocytopenia
- Pneumonitis
- Pulmonary fibrosis
- Cyanosis
- ECG abnormality
- C. difficle associated diarrhea
- Optic neuritis
- Pseudotumor cerebri
- Psychosis
- Vasculitis
Common
- Nausea
- Headache
- Anorexia
- Abdominal pain
- Diarrhea
- Flatulence
- Asthenia
- Vertigo
- Nystagmus
- Dizziness
- Confusion
- Depression
- Alopecia
- Yellow/brown urine
- Sialadenitis
- Fever
- Pruritus
- Urticaria
- Arthralgia
- Myalgia
- Rigors
Pharmacology
- Half-life: 45-60min
- Metabolism: Hepatic
- Excretion: Urine primarily (30-40% unchanged); Bile
- Mechanism of Action: Inactivates bacterial ribosomal proteins
Antibiotic Sensitivities[4]
Key
- S susceptible/sensitive (usually)
- I intermediate (variably susceptible/resistant)
- R resistant (or not effective clinically)
- S+ synergistic with cell wall antibiotics
- U sensitive for UTI only (non systemic infection)
- X1 no data
- X2 active in vitro, but not used clinically
- X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
- X4 active in vitro, but not clinically effective for strep pneumonia
See Also
References
- ↑ Nitrofurantoin: Drug information. UpToDate. www.uptodate.com. Accessed April 1, 2019.
- ↑ Nitrofurantoin: Drug information. UpToDate. www.uptodate.com. Accessed April 1, 2019.
- ↑ Spring PJ, Sharpe DM, Hayes MW. Nitrofurantoin and peripheral neuropathy: A forgotten problem? Med J Aust 2001;174:153-4.
- ↑ Sanford Guide to Antimicrobial Therapy 2014