A 32-year-old man with newly diagnosed HIV-1 infection is started on combination antiretroviral therapy. Which is the most common cause of treatment failure in antiretroviral-naïve patients in India?

Explanation

## Most Common Cause of ART Failure in Naïve Patients **Key Point:** Non-adherence (poor medication compliance) is the single most common cause of virological failure and emergence of drug resistance in HIV-1 patients starting antiretroviral therapy, particularly in resource-limited settings like India. ### Why Non-Adherence Dominates 1. **Epidemiological reality**: Studies consistently show that >90% of virological failures in treatment-naïve patients are attributable to suboptimal adherence rather than intrinsic drug resistance. 2. **Barrier in India**: Factors include: - Complex regimen burden (multiple pills, multiple times daily) - Stigma and disclosure issues - Cost and access challenges despite government programs - Side effects (nausea, lipodystrophy, CNS symptoms) - Lack of adherence counselling infrastructure ### Mechanism of Failure via Non-Adherence Subtherapeutic drug levels → Incomplete viral suppression → Selection of resistant mutants → Virological rebound with resistant virus. **Clinical Pearl:** Even 95% adherence is insufficient for sustained viral suppression with some regimens; >95% is typically required. **High-Yield:** In NEET PG, when asked about "most common cause of treatment failure" in ART-naïve patients, the answer is non-adherence unless the stem explicitly states "in a fully adherent patient" (which would shift focus to resistance or pharmacokinetic issues). ### Comparison with Other Causes | Cause | Frequency in Naïve Patients | Typical Timeline | |-------|------------------------------|------------------| | Non-adherence | ~90% of failures | Weeks to months | | Primary resistance | 5–15% (varies by region) | At baseline | | IRIS | Immune event, not failure | 2–12 weeks post-ART | | Hepatic impairment | Rare unless advanced cirrhosis | Variable | **Mnemonic — ADHERE: A**dhesion (compliance), **D**rug interactions, **H**epatorenal function, **E**merging resistance, **R**egimen complexity, **E**nvironmental/social barriers.