Anorexia, nausea, emesis are the most frequent reactions; less frequently, abdominal pain and diarrhea: rarely, hepatitis. This dose-related toxicity reaction can be minimized by reduction of dosage, especially in the female patient.
Pulmonary sensitivity reactions, which can be acute, subacute, or chronic. Acute reaction is commonly manifested by fever, chills, cough, chest pain, dyspnea, pulmonary infiltration with consolidation or pleural effusion on X-ray, and eosinophilia. The acute reactions usually occur within the first week of treatment and resolve with cessation of the drug therapy.
Subacute or chronic pulmonary reaction is associated with prolonged therapy. Insidious onset of malaise, dyspnea on exertion, cough, altered pulmonary function, and roentgenographic and histologic findings of diffuse interstitial pneumonitis or fibrosis or both are common manifestations. Impaired pulmonary function may result even after cessation of the drug therapy.
Maculopapular, erythematous, or eczematous eruption, pruritus, urticaria, angioedema.
Other sensitivity reaction: anaphylaxis, asthmatic attack in patients with history of asthma, cholestatic jaundice, drug fever, arthralgia.
Hemolytic anemia, granulocytopenia, eosinophilia, megaloblastic anemia. Return of the blood picture to normal has followed cessation of therapy.
Peripheral neuropathy, headache, dizziness, nystagmus and drowsiness.
Transient alopecia. As with other antimicrobial agents, superinfections by resistant organisms may occur: With nitrofurantoin, however, these are limited to the genitourinary tract because suppression of normal bacterial flora elsewhere in the body does not occur.
is the organism most commonly implicated in superinfections in patients with nitrofurantoin.