Using this page · Individualise medicines monitoring

This medicines monitoring page has been written using publications and expert opinion. It is designed to save clinician time, but not replace professional responsibility. When using this page you should: ensure an individualised monitoring plan is developed in partnership with the patient and take account of any locally agreed advice and guidance.

Before starting

Consider

  • Baseline
    • Estimated glomerular filtration rate
    • G6PD deficiencycontraindicated if deficiency
    • Liver function tests
    • Porphyriacontraindicated

Interpreting renal function

Contraindicated if eGFR is less than 30mL/minute/1.73m2.
If eGFR less than 45 mL/min/1.73m2, normally avoid unless used with caution as a short course only (3 to 7 days). Indications include uncomplicated lower urinary tract infection caused by suspected or proven multi-drug resistant bacteria where benefit outweighs risk.

Continued until stable

Consider

  • Periodically
    • Estimated glomerular filtration ratelong-term treatment contraindicated if less than 45mL/minute/1.73m2
    • Liver function testscholestatic jaundice can occur with short-term (2 week) therapy
    • Pulmonary symptomsespecially important in elderly

Ongoing once stable

Consider

  • Periodically
    • Estimated glomerular filtration ratelong-term treatment contraindicated if less than 45mL/minute/1.73m2
    • Liver function testschronic active hepatitis, occasionally leading to hepatic necrosis, is possible with long-term (greater than 6 months) therapy
    • Pulmonary symptomsespecially important in elderly

Abnormal results

Respond to results and symptoms

Consider stopping if the person develops unexplained:

  • pulmonary symptoms: identifying effects and taking action early will positively affect outcome. Minor symptoms such as fever, chills, cough and dyspnoea may be significant and should be investigated. It is possible that pulmonary function may be impaired permanently, even after cessation of therapy.
  • hepatotoxicity
  • haematological toxicity
  • neurologic syndrome

Urinary effects

People taking nitrofurantoin are susceptible to false positive urinary glucose (if tested for reducing substances).

Notes

Advice to patients

Advise patients to report any signs or symptoms of:

  • pulmonary toxicity (e.g. cough; chest pain; dyspnoea)
  • hepatotoxicity (note onset can be insidious and non-specific: e.g. nausea, rash, headache, flu-like symptoms)
  • peripheral neuropathy (sensory as well as motor involvement)
  • haemolysis

Bibliography

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