Glossary

severity – a measure of how bad something is.

Minimum Effective Concentration (MEC) – the lower level of a drug in the body that will still be effective.

What happens when you take a drug?

decimal fraction – a fraction turned into a number by dividing the top part by the bottom part. For example, the decimal fraction for 3/5 is 0.6.

half-life (T1/2) – the time taken a drug to clear from the highest concentration to half this level. Drugs have different half-lives in different compartments (ie half-life in blood can be different from the half-life inside a cell). It take 5 x the half-live for a drug to be considered cleared.

high level resistance – when an HIV drug no longer works against the virus.