From the FDA Drug Label
WARNINGS: Pulmonary reactions: ACUTE, SUBACUTE, OR CHRONIC PULMONARY REACTIONS HAVE BEEN OBSERVED IN PATIENTS TREATED WITH NITROFURANTOIN. Hepatotoxicity: Hepatic reactions, including hepatitis, cholestatic jaundice, chronic active hepatitis, and hepatic necrosis, occur rarely. Neuropathy: Peripheral neuropathy, which may become severe or irreversible, has occurred. Hemolytic anemia: Cases of hemolytic anemia of the primaquine-sensitivity type have been induced by nitrofurantoin. Clostridium difficile-associated diarrhea: Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including nitrofurantoin, and may range in severity from mild diarrhea to fatal colitis.
Macrobid is contraindicated in:
- Patients with renal impairment (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine) 1
- Patients with hepatic impairment or a history of hepatotoxicity 1
- Patients with a history of hemolytic anemia or glucose-6-phosphate dehydrogenase deficiency 1
- Patients with pulmonary reactions or a history of pulmonary disease 1
- Patients with peripheral neuropathy or a history of neuropathy 1
From the Research
Macrobid (nitrofurantoin) is contraindicated in patients with creatinine clearance less than 30 mL/min, during the third trimester of pregnancy, in infants under one month of age, in patients with known hypersensitivity to nitrofurantoin, in patients with G6PD deficiency, and in patients with a history of cholestatic jaundice or hepatic dysfunction associated with previous nitrofurantoin use. The contraindications for Macrobid are based on the potential for reduced drug efficacy and increased risk of toxicity, as well as the risk of hemolytic anemia in certain populations.
- Patients with creatinine clearance less than 30 mL/min should avoid Macrobid due to reduced drug efficacy and increased risk of toxicity, as the medication accumulates in the bloodstream rather than concentrating in the urine 2.
- Macrobid is also contraindicated during the third trimester of pregnancy (weeks 38-42) because it can cause hemolytic anemia in the newborn due to the immature erythrocyte enzyme systems.
- Patients with known hypersensitivity to nitrofurantoin or any components of the formulation should avoid this medication.
- Additionally, Macrobid should not be used in infants under one month of age due to the risk of hemolytic anemia.
- Patients with G6PD deficiency should avoid nitrofurantoin as it can trigger hemolysis in these individuals, although the risk is lower than previously thought, with a total daily dose of 200 mg nitrofurantoin potentially being used for short (3-5 day) course urinary tract infection treatment without G6PD screening when accompanied by appropriate advice 3.
- Finally, Macrobid is contraindicated in patients with a history of cholestatic jaundice or hepatic dysfunction associated with previous nitrofurantoin use, as rechallenging these patients can lead to serious liver injury.