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Causality: well established
Causality assessment · Causality: well established
Adefovir Dipivoxil and Drug Resistance: 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.
Adefovir Dipivoxil ↔ Drug Resistance
n=275 co-reports · PRR 178.6 · ROR 227.6
Adefovir dipivoxil is a nucleotide analogue reverse transcriptase inhibitor for hepatitis B. Drug resistance is the expected consequence of selective pressure from incomplete viral suppression: HBV polymerase mutations reduce drug binding while maintaining replication fitness. 119 co-reports (PRR 115.3) reflect HIV/HBV co-infected populations. The label carries a boxed warning for nephrotoxicity, not resistance; however, resistance is a known class effect of NRTIs.
Boxed warning: adefovir label (nephrotoxicity). HBV resistance literature: Hepatology 2019, PMID: 31214345.
| Bradford Hill viewpoint | Status | Note |
|---|---|---|
| Temporality (necessary) | met | Documented in virology literature |
| Strength | met | PRR 115.3 with 119 co-reports |
| Consistency | met | Reproduced across NRTI class |
| Specificity | partial | Specific to reverse transcriptase inhibitors |
| Biological gradient | met | Resistance increases with monotherapy duration |
| Plausibility | met | Known polymerase mutation mechanism |
| Coherence | met | Coherent with viral evolution |
| Experiment | n/a | Measured in virology studies |
| Analogy | met | Other NRTIs show cross-class resistance |
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 Adefovir captured drug resistance as a tracked adverse event in a usable structure. Drug resistance is measured in virologic studies of treated patients, not in RCT AE tables.