Furadantin Side Effects

Generic name: nitrofurantoin

Medically reviewed by Drugs.com. Last updated on May 22, 2024.

Note: This document provides detailed information about Furadantin.

Applies to nitrofurantoin: oral capsule, oral suspension Side Effects associated with nitrofurantoin. Some dosage forms listed on this page may not apply specifically to the brand name Furadantin.

Applies to nitrofurantoin: oral capsule, oral suspension.

Precautions

If you or your child will be taking this medicine for a long time, it is very important that your doctor check you at regular visits for any problems or unwanted effects that may be caused by this medicine.

If you or your child's symptoms do not improve within a few days, or if they become worse, check with your doctor.

Diabetic patients that use urine sugar tests should be careful when using this medicine. Nitrofurantoin may cause false test results with some urine sugar tests. Check with your doctor before changing your diet or the dose of your diabetes medicine.

Liver problems may occur while you are using this medicine. Stop using this medicine and check with your doctor right away if you are having more than one of these symptoms: stomach pain or tenderness; clay-colored stools; dark urine; decreased appetite; fever; headache; itching; loss of appetite; nausea and vomiting; skin rash; swelling of the feet or lower legs; unusual tiredness or weakness; or yellow eyes or skin.

Tell your doctor right away if you start having numbness, tingling, or burning pain in your hands, arms, legs, or feet. These may be symptoms of a condition called peripheral neuropathy.

Nitrofurantoin may cause diarrhea, and in some cases it can be severe. Do not take any medicine to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. If you have any questions about this, or if mild diarrhea continues or gets worse, check with your doctor.

This medicine may cause the urine to become a rust-yellow to brown color. This side effect does not require medical attention.

Serious side effects of Furadantin

Along with its needed effects, nitrofurantoin (the active ingredient contained in Furadantin) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking nitrofurantoin:

Other side effects of Furadantin

Some side effects of nitrofurantoin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to nitrofurantoin: compounding powder, oral capsule, oral suspension.

Gastrointestinal adverse events

• Common (1% to 10%): Nausea, emesis, flatulence
• Uncommon (0.1% to 1%): Abdominal pain, diarrhea
• Frequency not reported: Dyspepsia, constipation, sialadenitis, pancreatitis, pseudomembranous colitis, Clostridioides difficile-associated diarrhea, parotitis^[Ref]

Nausea, emesis, and anorexia occurred most often; abdominal pain and diarrhea were less common. These side effects were dose-related and have been minimized by dose reduction. Many patients who could not tolerate the microcrystalline formulation were able to take the macrocrystals formulation without nausea.

The onset of pseudomembranous colitis symptoms has been reported during or after antimicrobial therapy.^[Ref]

Metabolic

• Common (1% to 10%): Anorexia
• Frequency not reported: Acute porphyria, false positive urinary glucose^[Ref]

Nervous system

• Common (1% to 10%): Headache
• Rare (0.01% to 0.1%): Peripheral neuropathy including optic neuritis (sensory and motor involvement), nystagmus, vertigo, dizziness, drowsiness
• Frequency not reported: Benign intracranial hypertension (pseudotumor cerebri), bulging fontanels, polyneuropathy (including optic neuritis), sensory loss, paresthesia, motor loss, neuropathy (generally beginning as paresthesia of the lower extremities and the hands and progressing to muscle weakness and wasting), cerebellar dysfunction
• Postmarketing reports: Optic neuritis^[Ref]

Peripheral neuropathy (which was sometimes severe or irreversible) has occurred; fatalities have been reported. Risk of peripheral neuropathy has been increased with renal dysfunction (CrCl less than 60 mL/min or clinically significant elevated serum creatinine), anemia, vitamin B deficiency, diabetes mellitus, electrolyte imbalance, and debilitating disease.

Polyneuropathy, which started peripherally with initial sensory loss and paresthesia but progressed to motor loss (often with severe muscle atrophy), has occurred during therapy. A predisposing condition in most of these patients was renal failure, which was often accompanied by anemia, diabetes, electrolyte imbalance, vitamin B deficiency, and debilitating disease. After stopping this drug, further deterioration generally halted and total or partial regression occurred in almost 80% of affected patients. These reactions were sometime severe or irreversible but were rarely fatal.^[Ref]

Hematologic

• Common (1% to 10%): Eosinophilia, decreased hemoglobin
• Rare (0.01% to 0.1%): Aplastic anemia
• Frequency not reported: Hemolytic anemia, leukopenia, agranulocytosis, granulocytopenia, megaloblastic anemia, glucose-6-phosphate dehydrogenase deficiency anemia, thrombocytopenia, cyanosis secondary to methemoglobinemia^[Ref]

Hepatic

• Common (1% to 10%): Elevated AST, elevated ALT
• Rare (0.01% to 0.1%): Liver failure (may be fatal), cholestatic jaundice, chronic active hepatitis (including fatalities)
• Frequency not reported: Hepatic necrosis, autoimmune hepatitis, hepatic reactions (including hepatitis, cholestatic jaundice, chronic active hepatitis, hepatic necrosis), hepatotoxicity with concurrent pulmonary reactions, elevated bilirubin, hepatic toxicity (presented with jaundice, abdominal pain, malaise, nausea, anorexia)^[Ref]

Other

• Common (1% to 10%): Increased serum phosphorus/phosphate
• Frequency not reported: Fever, chills, malaise, asthenia, drug fever, superinfections due to resistant organisms (e.g., Pseudomonas species, Candida species), C difficile superinfections, increased alkaline phosphatase, increased lactate dehydrogenase^[Ref]

Respiratory

• Rare (0.01% to 0.1%): Chronic pulmonary reactions (symptoms included malaise, exertional dyspnea, cough, altered pulmonary function, radiologic/histologic findings of diffuse interstitial pneumonitis and/or fibrosis)
• Frequency not reported: Acute pulmonary reactions (symptoms included fever, chills, cough, chest pain, dyspnea, pulmonary infiltration with consolidation/pleural effusion on chest x-ray, eosinophilia), subacute pulmonary reactions, chronic/subacute/acute pulmonary hypersensitivity reactions, cough, dyspnea, permanent impairment of pulmonary function, pulmonary fibrosis, bronchiolitis obliterans organizing pneumonia, asthma attacks (in patients with history of asthma), pulmonary infiltration with consolidation/pleural effusion on x-ray^[Ref]

Chronic pulmonary reactions occurred rarely, generally in patients who received continuous therapy for at least 6 months; such reactions were more common in elderly patients.

Acute pulmonary reactions generally occurred within the first week of therapy and were reversible when therapy was stopped; resolution was often dramatic. Acute pulmonary reactions were commonly manifested by fever, chills, cough, chest pain, dyspnea, pulmonary infiltration with consolidation/pleural effusion on chest x-ray, and eosinophilia.

In subacute pulmonary reactions, fever and eosinophilia occurred less often than in the acute form. After therapy was stopped, recovery sometimes required several months.^[Ref]

Cardiovascular

• Rare (0.01% to 0.1%): Collapse, cyanosis, changes in ECG (e.g., nonspecific ST/T wave changes, bundle branch block)
• Frequency not reported: Vasculitis, cardiopulmonary failure (leading to collapse and death), chest pain^[Ref]

Changes in ECG (e.g., nonspecific ST/T wave changes, bundle branch block) have occurred, associated with pulmonary reactions; vasculitis was sometimes associated with pulmonary reactions.^[Ref]

Dermatologic

• Rare (0.01% to 0.1%): Exfoliative dermatitis, erythema multiforme (including Stevens-Johnson syndrome)
• Frequency not reported: Pruritus, urticaria, allergic skin reactions, alopecia/transient alopecia, angioedema/angioneurotic edema, cutaneous vasculitis, maculopapular eruptions, erythematous eruptions, eczematous eruptions, rash, drug rash with eosinophilia and systemic symptoms (DRESS) syndrome^[Ref]

Psychiatric

• Rare (0.01% to 0.1%): Depression, euphoria, confusion, psychotic reactions^[Ref]

Hypersensitivity

• Frequency not reported: Anaphylaxis
• Postmarketing reports: Hypersensitivity reactions^[Ref]

Hypersensitivity reactions were the most frequently reported side effect during postmarketing experience.^[Ref]

Musculoskeletal

• Frequency not reported: Lupus-like syndrome/lupus erythematous-like syndrome, arthralgia, myalgia, muscle atrophy, increased creatine phosphokinase

Lupus-like syndrome has been associated with pulmonary reaction.

Renal

• Frequency not reported: Interstitial nephritis^[Ref]

Genitourinary

• Frequency not reported: Yellow or brown discoloration of urine, genitourinary tract superinfections (by fungi or resistant organisms [e.g., Pseudomonas, Candida]), dark colored urine^[Ref]

Ocular

• Frequency not reported: Amblyopia, retinopathy (due to intraretinal crystals), diplopia^[Ref]

See also:

Frequently asked questions

• What antibiotics are used to treat UTI?
• What is "dual release" nitrofurantoin?

Further information

Furadantin side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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