Nitrofurantoin Monohydrate Macrocrystals (Macrodantin) Risks, Warnings, and Complications

PULMONARY TOXICITY: There are reports of acute, subacute, and chronic pulmonary reactions, including possibly fatal reactions, in people who took nitrofurantoin. You will need to discontinue nitrofurantoin if you develop lung problems. Chronic pulmonary reactions such as diffuse interstitial pneumonitis or pulmonary fibrosis are rare and generally occur in people who have been taking nitrofurantoin for 6 months or longer. Your doctor will monitor you closely if you are on long-term treatment with nitrofurantoin. Tell your doctor without delay if you develop breathing difficulties, shortness of breath, or chest pain while on this medicine.

LIVER INJURY: Patients treated with nitrofurantoin can develop liver damage, including inflammation (hepatitis) and obstruction of bile flow (cholestatic jaundice). Rarely, these complications can be fatal. Your doctor will monitor you periodically for changes in liver function tests that can point towards a liver injury. If you develop symptoms of hepatitis (liver inflammation), you will need to discontinue nitrofurantoin. 

PERIPHERAL NEUROPATHY: There are reports of peripheral neuropathy (damage to nerves located outside the brain and spinal cord) in people taking nitrofurantoin. This nerve damage can be severe, irreversible, and possibly fatal. Having decreased renal function, elevated serum creatinine, anemia, electrolyte imbalance, vitamin B deficiency, diabetes mellitus, or a debilitating disease can increase the risk of developing peripheral neuropathy. Tell your doctor if you have renal impairment (reduced kidney function). Your doctor will monitor renal function if you are on long-term nitrofurantoin therapy.

OPTIC NEURITIS: There are post-marketing reports of optic neuritis (inflammation and damage of the optic nerve in the eye) in people who took nitrofurantoin formulations. Tell your doctor without delay if you develop eye pain or vision changes while on this medication.

HEMOLYTIC ANEMIA: There are reports of hemolytic anemia in people who took nitrofurantoin. This is a type of anemia in which there is a faster than normal destruction of red blood cells. This complication appears to be linked to a condition called G6PD (glucose-6-phosphate dehydrogenase) deficiency which is present in 10% of African-American people and also Near-Eastern and Mediterranean ethnic groups. Tell your doctor immediately if you develop signs and symptoms such as pale skin, weakness, dizziness, confusion, or fever. The condition is usually reversible after discontinuing nitrofurantoin. 

CLOSTRIDIUM DIFFICILE ASSOCIATED DIARRHEA: Nitrofurantoin and other antibiotics can cause a severe intestinal condition called Clostridium difficile associated diarrhea (CDAD). It occurs due to the overgrowth of a bacteria called Clostridium difficile in the gut after the gut microbiome is disrupted by antibiotic treatment. The symptoms can range from mild diarrhea to potentially fatal colitis with severe watery or bloody diarrhea. Tell your doctor if you develop serious symptoms such as bloody or watery diarrhea with or without fever and stomach cramps up to 2 months or more after taking an antibiotic. 

LABORATORY TESTS: Nitrofurantoin can interfere with the results of certain lab tests and result in false test results, for example, if you have diabetes and test your urine for glucose. Tell all your doctors and lab personnel that you are on nitrofurantoin.