“…33 Combinations of NRTIs and raltegravir for PEP demonstrated a high level of safety and tolerability, but regimen completion was suboptimal, because many participants discontinued the medication prematurely or did not remember to take the second dose of raltegravir in the twice daily regimen. 11,[34][35][36] The fixeddrug single-pill coformulation of elvitegravir, cobicistat, FTC, and TDF allowed for the use of a single daily pill for PEP, but seemed to have higher rates of gastrointestinal symptoms and fatigue than raltegravir-based regimens, which may have led to product discontinuation. 12,37,38 A subsequent study found that the fixed dose combination of elvitegravir, cobicistat, FTC and TAF was well-tolerated, 39 but the use of the pharmacological booster has raised concerns about drug-drug interactions.…”