A patient with poorly controlled ART (CD4 145, VL 100k, intermittent adherence to DRV/c/TAF/FTC) and alcohol use disorder was admitted to the hospital in alcohol withdrawal and loaded with phenobarbital for management of withdrawal symptoms. ID was consulted to re-start ART. We ultimately decided on DTG bid + TDF/FTC (with plan to streamline to DTG qd + TAF/FTC once phenobarbital was out of patient's system), which did not seem ideal but seemed like an okay regimen. I was curious about results from HIVASSIST, which didn't seem to list this option initially.
| Score Code | Regimen | Weighted Score | Active Drugs | Total Pills | Frequency (x/day) |
|---|---|---|---|---|---|
| 3 | DTG/TDF/3TC | 2.75 | 2 | 2 | 2 |
| 3 | DTG+TDF/FTC | 2.95 | 2 | 3 | 2 |
| 3 | DRV/r+TDF/FTC | 3.45 | 2 | 3 | 1 |
| 5 | RAL+EFV/TDF/FTC | 6.15 | 3 | 3 | 1 |
| 5 | DRV/r+EFV/TDF/FTC | 6.3 | 3 | 3 | 1 |
Options for ART in the setting of phenobarbital are limited. I would suggest running the case again, but 'unselect' TDF from the 'excluded' list. HIV-ASSIST pre-excludes TDF to simplify display of results. However, in some circumstances (with drug interactions) there may be instances in which TDF is a reasonable consideration and TAF is excluded due to drug interactions.
DHHS guidelines suggest: all INSTI's are either contraindicated or 'do not coadminister', including RAL and DTG. Liverpool drug interaction guide, however, does suggest that if unavoidable, one could consider RAL (BID dosing) or DTG (50mg BID). Among other agents, there are no interactions expected between TDF and phenobarbital per the University of Liverpool drug interaction guide, and there is limited data with EFV. An updated list of HIVASSIST results, if including TDF options is listed below. As you noted TDF/FTC+DTG BID is an option that could be considered with plans to convert to TAF/FTC+DTG later: