Nitrofurantoin side effects

What side effects can nitrofurantoin have?

Below you will find the most important information about possible known side effects of nitrofurantoin.
These side effects do not occur, but you can. Because every person reacts differently to medication. Please also note that the type and frequency of side effects may vary depending on the drug formulation (eg tablet, syringe, ointment).

Common side effects:
Nausea and vomiting, loss of appetite, nervous disorders such as paralysis (especially in long-term treatment of patients with renal impairment and diabetics), emotional disorders.

Occasional side effects:
Pulmonary reactions (shortness of breath, pneumonia, pulmonary fibrosis), headache, dizziness, allergic reactions, drug fever.

Rare side effects:
liver damage, liver inflammation, anemia (in patients with glucose-6-phosphate dehydrogenase deficiency), parotitis.

Isolated side effects:
Severe allergic reactions (shock), blood cell reduction, anemia, formation of antibodies to the body’s own cells.

Special features:
The active substance may cause severe acute lung complaints such as shortness of breath, coughing, accumulation of water in the lungs and fever. If such symptoms occur during the treatment, consult a doctor.

After long-term use – usually more than a year – and often in older women, pneumonia and the transformation of lung tissue into non-functional connective tissue (fibrosis) occur. These side effects can sometimes be life-threatening. The Federal Institute for Drugs and Medical Devices (BfArM) therefore strongly advises against long-term treatment with nitrofurantoin.

During treatment with drugs containing nitrofurantoin, a harmless browning of the urine may occur.

What interactions does nitrofurantoin show?

Please note that the interactions may vary depending on the drug formulation of a drug (eg tablet, syringe, ointment).

The effect of nitrofurantoin is changed by other active ingredients as follows:

  • Magnesium-containing stomach acid (acid-binding agents) reduce the absorption of the active substance into the body and thus its effectiveness.
  • Nalidixic acid (an antibiotic against bacteria) reduces or even completely eliminates the effect.
  • Gout such as probenecid and sulfinpyrazone reduce the effects and increase the side effects.
  • Propantheline bromide, a gastric agent, promotes the absorption of the drug into the body and thereby enhances its action.

Potential Nitrofurantoin side effects may include: