What Is Nitrofurantoin and How Does It Work?
Nitrofurantoin is a prescription medication used to treat the symptoms of urinary tract infection (UTI) caused by bacteria such as Escherichia coli, Enterobacter spp, Klebsiella spp, Staphylococcus aureus, and S. saprophyticus.
- Nitrofurantoin is available under the following different brand names: Macrobid, Macrodantin, and Furadantin.
What Are Side Effects Associated with Using Nitrofurantoin?
Common side effects of Nitrofurantoin include:
- headache,
- dizziness,
- drowsiness,
- weakness,
- gas,
- indigestion,
- loss of appetite,
- nausea,
- vomiting,
- muscle or joint pain,
- rash,
- itching, and
- temporary hair loss
Serious side effects of Nitrofurantoin include:
- hives,
- difficulty breathing,
- swelling in the face or throat,
- fever,
- sore throat,
- burning eyes,
- skin pain,
- red or purple skin rash with blistering and peeling,
- severe stomach pain,
- diarrhea that is watery or bloody (even if it occurs months after your last dose),
- vision problems,
- fever,
- chills,
- cough,
- chest pain,
- numbness, tingling, or burning in hands or feet,
- severe pain behind the eyes,
- pale skin,
- weakness,
- joint pain or swelling with fever,
- swollen glands,
- muscle aches,
- pain, redness, or swelling in the lower jaw,
- severe headaches,
- ringing in ears,
- dizziness,
- nausea,
- vision problems,
- upper stomach pain (that may spread to the back),
- vomiting,
- dark urine, and
- yellowing of the skin or eyes
Rare side effects of Nitrofurantoin include:
- none
What Are Dosages of Nitrofurantoin?
Adult dosage
Capsule, macrocrystals
- 25mg
- 50mg
- 100mg
- 50-100mg orally every 6 hours for 7 days or for 3 days after obtaining a sterile urine
Capsule, monohydrate/macrocrystals
- 100mg
- 100mg orally every 12 hours for 7 days or for 3 days after obtaining a sterile urine
Oral suspension
- 25mg/5mL
- Longer-term prophylaxis/suppression: 50-100 mg macrocrystals orally at bedtime for up to 12 months.
Pediatric dosage
Capsule, macrocrystals
- 25mg
- 50mg
- 100mg
Capsule, monohydrate/macrocrystals
- 100mg
Oral suspension
- 25mg/5mL
- Children older than 1 month of age: 5-7 mg/kg/day orally divided every 6 hours for 7 days
- UTI prophylaxis: 1-2 mg/kg orally at bedtime or 2 divided doses
- Macrocrystals (Macrodantin, Furadantin, and equivalents): children older than 12 years of age: 50-100mg orally every 6 hours for 7 days or for 3 days after obtaining sterile urine
- Monohydrate/macrocrystals (Macrobid and equivalents): children older than 12 years of age: 100 mg orally every 12 hours for 7 days or for 3 days after obtaining a sterile urine
- Long-term prophylaxis/suppression: children older than 12 years of age: 50-100 mg macrocrystals orally at bedtime for up to 12 months.
Dosage Considerations – Should be Given as Follows:
- Avoid long-term UTI suppression; possible pulmonary toxicity; safer alternatives are available
- Loses effectiveness in patients with creatinine clearance (CrCl) less than 60 mL/min due to inadequate urine concentration (Beers criteria)
- Monitor renal function; renally excreted; decreased renal function more likely in elderly
- Monitor liver function
- Take with food or milk
- Dual release macrocrystals indicated only for patients older than 12 years of age for acute UTIs (cystitis) caused by E Coli or S saprophyticus
What Other Drugs Interact with Nitrofurantoin?
If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first
- Nitrofurantoin has no known severe interactions with other drugs
- Nitrofurantoin has serious interactions with the following other drugs:
- Nitrofurantoin has moderate interactions with at least 35 other drugs
- Nitrofurantoin has mild interactions with at least 13 other drugs
This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, or concerns.
What Are Warnings and Precautions for Nitrofurantoin?
Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately
Contraindications
- Hypersensitivity to IV components, beta-lactams, or other drugs in this class
- Renal failure (anuria, oliguria, or CrCl less than 60 mL/min)
- Pregnancy at term (38-42 weeks of gestation)
- History of hepatic dysfunction/cholestatic jaundice with nitrofurantoin
- Neonates (younger than 28 days)
- Hypersensitivity
Effects of drug abuse
- None
Short-Term Effects
- See “What Are Side Effects Associated with Using Nitrofurantoin?”
Long-Term Effects
- See “What Are Side Effects Associated with Using Nitrofurantoin?”
Cautions
- Caution in patients with G6PD deficiency (may increase the risk for hemolytic anemia)
- Avoid long-term use in the elderly (may increase the risk for pulmonary toxicity)
- Renal impairment
- Discontinue if paresthesia or hemolysis develops
- Risk of occasional hepatotoxicity and pulmonary toxicity
- Protect from light
- Peripheral neuropathy may occur; the risk may increase in patients diagnosed with anemia, diabetes, vitamin B deficiency, or electrolyte imbalance (use caution)
- Acute/chronic pulmonary reactions (eg., cough, interstitial pneumonitis, or fibrosis) reported
- Bacterial superinfections may occur with prolonged treatment
Pregnancy and Lactation
- Use in pregnancy is contraindicated at term. Use may be acceptable during pregnancy. Medication crosses the placenta but is not well distributed.
- Nitrofurantoin enters breast milk; discontinue the drug or do not use it.
