With only about one-quarter of Americans living with HIV being virally suppressed, more Americans becoming newly infected each year, and an aging cohort of HIV specialty care providers (who started providing care to HIV infected persons in the 1980’s), it is essential that health professional training programs incorporate curricula and experience regarding HIV prevention, diagnosis, care, and treatment.
Cobicistat is a derivative of ritonavir and a potent inhibitor of CYP3A. As does ritonavir, it "boosts" blood levels of other substrates of this enzyme but, unlike ritonavir, it has no activity against HIV. It has been developed as a pharmacokinetic enhancer of the integrase inhibitor elvitegravir and of some PIs.
It has been demonstrated previously that ritonavir significantly increases serum levels of inhaled and intranasal fluticasone and that coadministration with fluticasone should be avoided. Few studies have examined interactions between PIs and other corticosteroids. At the 19th Conference on Retroviruses and Opportunistic Infections, researchers presented results from a randomized controlled PK study of interactions of both darunavir/ritonavir and ritonavir (alone) with inhaled beclomethasone.
Tenofovir alafenamide fumarate (TAF) is an investigational prodrug of tenofovir. You will recall that the current tenofovir product, tenofovir disoproxil fumarate (TDF), also is a prodrug; so why are we interested in a new prodrug? This largely has to do with efforts to decrease the toxicity associated with tenofovir.