Macrodantin and Urinary Tract Infections

Are you at risk for a UTI?
According to the American Congress of Obstetricians and Gynecologists (ACOG) Guidelines, risk factors for Premenopausal and Postmenopausal women include the following:

Premenopausal Women
  • History of UTI
  • Frequent or recent sexual activity
  • Diaphragm contraception use
  • Use of spermicidal agents
  • Increasing parity
  • Diabetes mellitus
  • Obesity
  • Sickle cell trait
  • Anatomic congenital abnormalities
  • Urinary tract calculi
  • Neurologic disorders or medical conditions requiring indwelling or repetitive bladder catheterization
Postmenopausal Women
  • Vaginal atrophy
  • Incomplete bladder emptying
  • Poor perineal hygiene
  • Rectocele, cystocele, urethrocele, or uterovaginal prolapse
  • Lifetime history of UTI
  • Type 1 diabetes mellitus

Every year, urinary tract infections account for nearly 10 million doctor visits. A urinary tract infection (UTI) occurs when bacteria (germs) enter the urinary tract and multiply. One in five women will have at least one urinary tract infection in her lifetime. (Reference: “A to Z Health Guide”; The National Kidney Foundation A UTI typically produces swelling and pain in the urinary tract, but can also be asymptomatic (asymptomatic bacteriuria) and only detected by your doctor. If not treated properly, the bacteria from a UTI can move up to the kidneys and cause a more serious type of infection.

In addition, many women experience frequent UTIs. If you experience frequent UTIs, an antibiotic might be prescribed to you by your doctor to prevent infections. (Reference: Management of uncomplicated urinary tract infections, EWJM Volume 176 January 2002 wjm 55)

Pregnant women are not more likely to get UTIs, but UTIs may be more serious during pregnancy. A pregnant woman with a UTI should consult her doctor to avoid potential problems like high blood pressure and premature delivery of her baby. (Reference: “A to Z Health Guide”; The National Kidney Foundation While there have been no adequate and well-controlled studies in pregnant women, animal studies have shown no fetal risk or impaired fertility. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

There are several antibiotics used to treat UTIs, but if you experience recurrent UTIs, you may want to ask your doctor about Macrodantin. Macrodantin is a proven oral antibiotic used to effectively treat and prevent frequent urinary tract infections. Macrodantin is also considered a pregnancy category B drug. Macrodantin is a brand name drug, not a generic. Although generics have the exact same active drug components by law, the inactive ingredients can affect the drugs absorption into the body. (References: FDA U.S. Food and Drug Administration. and
[September 15, 2010]
) Talk with your doctor to see if Macrodantin might be right for you.


Macrodantin is specifically indicated for the treatment of urinary tract infections when due to susceptible strains of Escherichia coli, enterococci, Staphylococcus aureus, and certain susceptible strains of Klebsiella and Enterobacter species. Nitrofurantoin is not indicated for the treatment of pyelonephritis or perinephric abscesses.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Macrodantin and other antibacterial drugs, Macrodantin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Nitrofurantoins lack the broader tissue distribution of other therapeutic agents approved for urinary tract infections. Consequently, many patients who are treated with Macrodantin are predisposed to persistence or reappearance of bacteriuria. Urine specimens for culture and susceptibility testing should be obtained before and after completion of therapy. If persistence or reappearance of bacteriuria occurs after treatment with Macrodantin, other therapeutic agents with broader tissue distribution should be selected.

In considering the use of Macrodantin, lower eradication rates should be balanced against the increased potential for systemic toxicity and for the development of antimicrobial resistance when agents with broader tissue distribution are utilized. Be sure to speak with your healthcare provider about the benefits and potential risks of starting any medical treatment, including treatment with Macrodantin. Several reproduction studies have been performed in rabbits and rats at doses up to six times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to nitrofurantoin. In a single published study conducted in mice at 68 times the human dose (based on mg/kg administered to the dam), growth retardation and a low incidence of minor and common malformations were observed. However, at 25 times the human dose, fetal malformations were not observed; the relevance of these findings to humans is uncertain. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.


CONTRAINDICATIONS: Anuria, oliguria, or significant impairment of renal function (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine) are contraindications. Treatment of this type of patient carries an increased risk of toxicity because of impaired excretion of the drug. Because of the possibility of hemolytic anemia due to immature erythrocyte enzyme systems (glutathione instability), the drug is contraindicated in pregnant patients at term (38-42 weeks' gestation), during labor and delivery, or when the onset of labor is imminent. For the same reason, the drug is contraindicated in neonates under one month of age. Macrodantin is contraindicated in patients with a previous history of cholestatic jaundice/hepatic dysfunction associated with nitrofurantoin. Macrodantin is also contraindicated in those patients with known hypersensitivity to nitrofurantoin.

PRECAUTIONS: Patients should be advised to take Macrodantin with food to further enhance tolerance and improve drug absorption. Patients should be instructed to complete the full course of therapy; however, they should be advised to contact their physician if any unusual symptoms occur during therapy. Many patients who cannot tolerate microcrystalline nitrofurantoin are able to take Macrodantin without nausea. Patients should be advised not to use antacid preparations containing magnesium trisilicate while taking Macrodantin. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Macrodantin or other antibacterial drugs in the future. Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.

For more information, read the full prescribing information for Macrodantin.