Protease inhibitor (pharmacology)

Protease inhibitors, also known as peptidase inhibitors or proteinase inhibitors, are a class of antiretroviral drugs used primarily to treat viral infections, particularly HIV/AIDS and hepatitis C. They function by interfering with the activity of proteases, which are enzymes that viruses need to cleave newly synthesized viral proteins into their mature, functional forms. By inhibiting these proteases, the assembly of new infectious viral particles is blocked, reducing the viral load in the body.

Proteases are critical for the life cycle of many viruses, including HIV. The HIV protease, for instance, cleaves the Gag and Pol polyproteins into individual proteins such as reverse transcriptase, integrase, and capsid proteins that are essential for viral replication. Without functional proteases, the resulting virions remain immature and non-infectious.

Protease inhibitors are typically used in combination with other antiretroviral drugs as part of highly active antiretroviral therapy (HAART) or antiretroviral therapy (ART). This combination therapy approach helps to suppress viral replication effectively and prevents the emergence of drug resistance.

Common side effects associated with protease inhibitors can vary depending on the specific drug and individual patient factors, but may include gastrointestinal issues (nausea, diarrhea), metabolic complications (insulin resistance, hyperlipidemia), and lipodystrophy (changes in body fat distribution). Newer protease inhibitors are often associated with fewer side effects than older generations.

The discovery and development of protease inhibitors represented a significant advancement in the treatment of HIV/AIDS, transforming the prognosis from a rapidly fatal disease to a manageable chronic condition for many individuals. Research continues to focus on developing more potent and selective protease inhibitors with improved pharmacokinetic profiles and reduced side effects. Furthermore, research is ongoing to explore the potential use of protease inhibitors for other diseases where protease activity plays a crucial role, such as certain cancers and neurodegenerative disorders.