Recent pharmacovigilance data highlight significant INSTI drug resistance signals for both first- and second-generation integrase inhibitors. An analysis of the WHO VigiBase database reveals disproportionate reporting for drugs like raltegravir and dolutegravir. This study underscores the need for clinical vigilance as these agents become cornerstones of antiretroviral therapy (ART) globally. Consequently, monitoring resistance patterns remains a vital part of HIV care.

Identifying INSTI Drug Resistance Signals

Researchers conducted a comprehensive disproportionality analysis using VigiBase, which contains over 35 million individual case safety reports (ICSRs). The study identified 1,084 cases involving exposure to integrase strand-transfer inhibitors. Specifically, the data showed significant reporting odds ratios (ROR) for all five available INSTIs. This includes first-generation raltegravir and second-generation dolutegravir. Furthermore, most reports were classified as serious, highlighting the clinical impact of resistance.

Implications for Global HIV Care

The findings suggest that even second-generation drugs, which possess a high genetic barrier, are not immune to resistance. Most reported cases involved male patients from Europe and the Americas. However, these signals are critically relevant for clinicians in all regions. Therefore, medical professionals should prioritize resistance monitoring in clinical settings. Additionally, they should use this information to guide treatment switches and preserve the efficacy of the INSTI class.

FAQs

What are the primary mutations associated with INSTI drug resistance?

Common mutations include N155H, Q148H/K/R, and Y143R. While second-generation inhibitors like dolutegravir are more robust, they can still fail if multiple mutations accumulate over time.

Why is resistance monitoring essential for INSTIs?

Monitoring is crucial because INSTIs are currently the preferred first-line treatment for HIV. Early detection of resistance prevents prolonged virological failure and reduces the risk of transmitting drug-resistant strains.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or a professional recommendation. Refer to the latest local and national guidelines for clinical practice.

References

Basílio HS et al. HIV resistance to integrase strand-transfer inhibitors: disproportionality analysis of individual case safety reports from the WHO global safety database (VigiBase). Curr Med Res Opin. 2026 Jun 11. doi: 10.1080/03007995.2026.2682588. PMID: 42275135.

World Health Organization (WHO). HIV drug resistance – brief report 2024. Available at: https://www.who.int/publications/i/item/9789240090330.

Stanford University. HIV Drug Resistance Database - INSTI Resistance Notes. Available at: https://hivdb.stanford.edu/dr-summary/resistance-notes/INSTI/.