Nitrofurantoin is an antibiotic that works against a broad spectrum of bacteria. Nitrofurantoin has been used effectively for a long time treatment of acute lower urinary tract infections in adults, children and pregnant women. Let’s get to know how it works, uses and precautions to take before use.
Overview of the drug
Nitrofurantoin is a synthetic antibacterial drug that is known to work against a broad spectrum of bacteria and is particularly effective against the main uropathogens, hence its use for the treatment of and prophylaxis against urinary tract infections. Resistance to nitrofurantoin has remained virtually unchanged since it first came in use. Nitrofurantoin is available under the trade name Macrobid 100mg capsules. It is available as:
- 100 mg
Alvogen Inc, Mylan laboratories Inc, Sandoz Inc are few of the manufacturers of this drug.
How does Nitrofurantoin work?
The exact mechanism of action is unknown but it is known to inhibit several bacterial enzymes thereby interfering with carbohydrate metabolism in bacteria. Nitrofurantoin has also been noted to cause inhibition of bacterial cell wall synthesis and DNA/RNA synthesis.
Uses and benefits
- Nitrofurantoin is used for the treatment and prophylaxis of acute or recurrent, uncomplicated urinary tract infections.
- Nitrofurantoin is particularly effective against many multi-drug resistant bacteria such as Escherichia coli, enterococci, staphylococci, Citrobacter, Klebsiella, and Enterobacter.
Dosage Instructions – It is for oral use
Acute Uncomplicated Urinary Tract Infections (UTIs): 50 mg four times daily for seven days.
Severe chronic recurrence (UTIs): 100 mg four times daily for seven days.
Long term suppression: 50-100 mg once a day.
Prophylaxis: 50 mg four times daily for the duration of the procedure and for three days thereafter.
Pediatric population-Children and Infants over three months of age:
Acute Urinary Tract Infections: 3mg/kg day in four divided doses for seven days.
Suppressive – 1mg/kg, once a day.
For children under 25 kg body weight consideration should be given to the use of Furadantin® Suspension.
Nitrofurantoin is, overall, a relatively safe drug. Side-effects usually occur due to long-term usage and include –
- Eating disorder ( loss of appetite), nausea, vomiting
- Darkening of urine
- Skin eruption – red, itchy bumps on the skin.
- It may cause fatal lung problems very rarely.
This drug causes hemolytic anemia in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency in red blood cells.
Antibiotic therapy can alter the normal flora of the colon and permit overgrowth of Clostridium difficile, whose toxin is believed to be a primary cause of antibiotic-associated colitis. The colitis is usually characterized by severe, persistent diarrhea and severe abdominal cramps, and may be associated with the passage of blood and mucus
The use of Nitrofurantoin has rarely been associated with hepatotoxicity (liver failure), including hepatitis, cholestatic jaundice, chronic active hepatitis, and hepatic necrosis.
The use of Nitrofurantoin is contraindicated in patients with anuria, oliguria, or significant renal impairment (CrCl < 60 mL/min). Urinary concentration of the drug is likely to be inadequate in these patients, increasing the risk of therapeutic failure.
The use of Nitrofurantoin has occasionally been associated with the development of peripheral neuropathy, which may be severe and irreversible. Patients at risk include the elderly and those with renal impairment, anemia, diabetes mellitus, electrolyte imbalance, vitamin B12 deficiency, diabetes, and/or debilitating diseases. Therapy with Nitrofurantoin should be administered cautiously in patients with one or more risk factors and/or preexisting peripheral neuropathy.
Chronic pulmonary reactions, generally in patients who have received continuous treatment for 6 months or longer have been reported with the use of Nitrofurantoin.
- Over the counter pain medicines such as Paracetamol or Ibuprofen can be taken along with this drug.
- Contraceptives are safe to use along with Nitrofurantoin.
- Antacid Therapy along with Nitrofurantoin can result in decreased absorption of Nitrofurantoin in the body.
- Uricosuric drugs such as probenecid and sulfinpyrazone (known to increase the excretion of uric acid in the urine) should not be administered along with Nitrofurantoin.
- Cystitis medicines such as potassium citrate or sodium citrate should be avoided while taking Nitrofurantoin.
- Nitrofurantoin can modify a number of laboratory test results such as –
- Urinary creatinine values may be elevated
- Glucose determination using Benedict´s solution may yield a false-positive result.
- Levels of bilirubin, alkaline phosphatase, and blood urea nitrogen may be spuriously elevated.
Your doctor should be notified before taking any medicine along with this drug.
Contraindications of Nitrofurantoin
Nitrofurantoin should not be used in patients with the following medical condition:
- Known hypersensitivity to Nitrofurantoin.
- Significant impairment of kidney function.
- Previous history of jaundice/liver dysfunction associated with Nitrofurantoin.
- Kidney diseases such as pyelonephritis or perinephric abscesses.
- In children less than one month of age (neonates).
Pregnancy and lactation
- Nitrofurantoin is contraindicated in pregnant patients during pregnancy term (38-42 weeks), when the onset of labor is forthcoming and during labor and delivery
- Nursing mothers – Trace amounts of Nitrofurantoin have been identified in human breast milk. You must always consult your doctor and make an informed decision based upon the fact that this drug can potentially cause serious adverse reactions in nursing neonates, taking into account the importance of the drug to the mother.
- Dose reduction is needed in patients suffering from kidney and liver diseases.
- Nitrofurantoin should not be used to treat viral infections like a common cold, flu, etc.
- Patients must never alter/stop the drug regimen without the doctor’s consent. If the medicine is stopped in between, the symptoms might reappear or may get aggravated. This can also increase the risk of developing bacterial resistance to the drug.
These drugs can be taken as alternatives only when prescribed by your doctor.
If for some reason an experienced doctor is not available around you, then you can contact us here.
Dr. Divya has been pursuing Dentistry for about 5 years now. Endodontics and Orthodontics are her areas of interest and she holds a BDS degree from Govt. Dental College, Vijayawada, AP.
Besides pursuing her career as a Dentist, she is passionate about Technical writing and is spending her free time in writing medical articles to bring awareness and share medical knowledge to the public.