Glossary

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?

Stevens-Johnson Syndrome – a type of severe rash that is luckily rare. This rash has been reported in 0.1–0.3% of people using NNRTIs. It can also occur with other drugs including antibiotics (including cotrimoxazole/Septrin). Any rash on an NNRTI should be shown to your doctor to decide whether treatment needs to be switched or can continue.

cross-resistance – when resistance to one drug causes resistance to other similar drugs.

This commonly happens for every class or family of HIV drugs: nukes, NNRTIs, PIs, integrase inhibitors and entry inhibitors.

BD (or bid) – a short hand term for medication dosing that means ‘twice-daily’.

See also q12H.

clinical cut-off (CCO) – a test result that is associated with an impact on clinical care. With resistance tests a lower CCO is the level below which a drug is still sensitive or active. This is often set at a 20% loss of activity (compared to wild-type HIV). An upper CCO is the level above which the drug is not considered active (ie resistant). This is often set at an 80% loss of activity (compared to wild-type HIV).