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Causality: well established
Causality assessment · Causality: well established
Nitrofurantoin and Peripheral neuropathy: is the FAERS signal real?
A written Bradford Hill assessment of one drug–event pair. The grade is a judgement about the signal, not a statement that this drug causes this event in any one person; FAERS counts are reports, not rates.
Nitrofurantoin ↔ Peripheral neuropathy
n=207 co-reports · PRR 2.8 · ROR 2.8
Nitrofurantoin can cause peripheral neuropathy that may become irreversible, particularly with prolonged use or renal impairment; 207 co-reports give PRR 2.8. The label warns of this effect and advises prompt withdrawal if numbness or paraesthesia appears.
Regulatory basis: nitrofurantoin prescribing information — peripheral neuropathy; caution in renal impairment and prolonged use.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Weeks of therapy |
| Strength | met | PRR 2.8 with 207 co-reports |
| Consistency | met | Reproduced across reports |
| Specificity | not established | Peripheral neuropathy has many causes |
| Biological gradient | met | Duration/exposure-related |
| Plausibility | met | Plausible axonal toxicity |
| Coherence | met | Fits nitrofurantoin neurotoxicity |
| Experiment | n/a | Not a routine trial endpoint |
| Analogy | met | Analogous to other drug-induced neuropathies |
This table is this page's own qualitative read of the literature cited above, not an automated or citation-gated assessment — see the note at the bottom of this page.
✗ No ClinicalTrials.gov results-posting trial in the top search hits for nitrofurantoin captured peripheral neuropathy as a tracked adverse event in a usable structure. Short-course urinary-tract trials were too brief to detect treatment-emergent neuropathy.