What is PI?

Protein index? I dunno

i thought you meant Pi like
pi= 3.14

lol ive got no idea either.

Whatever it is, I've never heard of it and I'm rather healthy so NO, I don't think it's something a healthy person should be worrying about.

lol me too.

For the drugs used in AIDS, please refer to protease inhibitor (pharmacology).

In biology and biochemistry, protease inhibitors are molecules that inhibit the function of peptidases (old name: protease, hence the term protease inhibitor). Many naturally-occurring protease inhibitors are proteins.

In medicine, protease inhibitor is often used interchangeably with alpha 1-antitrypsin (A1AT, which is abbreviated Pi for this reason).[1] A1AT is indeed the protease inhibitor most often involved in disease, namely in alpha 1-antitrypsin deficiency.

pharmacology:

Protease inhibitors (PIs) are a class of medication used to treat or prevent infection by viruses, including HIV and Hepatitis C. PIs prevent viral replication by inhibiting the activity of HIV-1 protease, an enzyme used by the viruses to cleave nascent proteins for final assembly of new virons.

Protease inhibitors have been developed or are presently undergoing testing for treating various viruses:

* HIV/AIDS: antiretroviral protease inhibitors (saquinavir, ritonavir, indinavir, nelfinavir etc.)
* Hepatitis C: experimental agents: BILN 2061, VX 950.

Given the specificity of the target of these drugs there is the risk, as in antibiotics, of the development of drug-resistant mutated viruses. To reduce this risk it is common to use together different drugs aimed at different targets.

Eiri, you are right. It is NOT something a healthy person needs to worry about.