Brian1966 - PrEP?

[Brian1966]

I was wondering why more drugs for treatment are not also being used for prevention.  Is it the strength / dosage of the drug or just the costs of getting regulatory approval for use as PrEP?

[Jim Allen]

Hiya, 

I moved your question into its own thread and will reply shortly, but first I have to put Caelan to bed, so ill be back with you later unless Micheal beats me to it. Best, Jim

[Jim Allen]

So here are my two cents,

Current PrEP options that I am aware of are:

tenofovir disoproxil fumarate (TDF),emtricitabine (FTC)
tenofovir disoproxil fumarate (TDF), lamivudine (3TC) (Uncommon PrEP option )
tenofovir alafenamide fumarate (TAF) + emtricitabine (TFC)
Cabotegravir (CAB)

Why not other drugs, well there is a lack of other specific PrEP studies, although plenty of combinations are approved for PEP and Treatment so we know a lot about what does/will work at stopping the HIV lifecycle and that is what PrEP does, the lack of regulatory approval, ease of use (the single pill combo or injection is easier than multiple pills), cost, clinical & side effects considerations, and half-life of some drugs will be a factor, resistance profile of certain drugs and resistance levels to certain drugs found in the wild, interactions with other health conditions etc.

So some drugs obviously would not be an option as PrEP for an HIV-negative person.  For example, ABC is a very effective drug, but some of its drawbacks include a short half-life, hypersensitivity risk, increased heart risks etc, which all require additional lab work and consideration, cost and time.

Generally speaking, when you see what is used either as primary or alternative options today as PEP/Treatment should in theory work as PrEP although plenty of reasons why not and, PrEP should be as easy as possible so who would want to take multiple pills or pay to study all of the PrEP options considering the move is onwards, toesards better drugs or things like injectables?

Anyhow, in brief, that's my general thoughts/knowledge on this very specific topic. I hope that helps.

[Brian1966]

Thanks Jim.

[Jim Allen]

👍