Archives

baseline – baseline refers to the start of any period being studied. For someone who is HIV positive, their baseline CD4 and viral load counts are the first tests they ever had taken. For someone entering a study, the baseline …

amino acids – amino acids are the building blocks of proteins. DNA codes for amino acids. Three nucleotides (segments of the genetic code) make one amino acid. Amino acids are critical to life, and have many functions in the way …

active – an active drug is a drug that still works to reduce viral load. The virus is still sensitive to that drug.

QD (or qd) – a short hand term for medication dosing that means ‘once-daily’. See also q24H.

BD (or bid) – a short hand term for medication dosing that means ‘twice-daily’. See also q12H.

TD (or tid) – a short hand term for medication dosing that means ‘take three times a day’. See also q8H.

Q12H (or q12H) – an abbreviated term for timing medication doses. q8H means every 8 hours.This is not the same as three times a day (tid or TD). q12H means every 12 hours. This is not the same as twice-daily …

codon – the word for the junction on genetic material (DNA or RNA) occupied by three nucleotides (or bases) to form an amino acid. In HIV it is most used when refering to drug resistance. There is an amino acid …

viral tropism see tropism.

tropism – the type of coreceptor used by HIV in order to attach to and then infect a cell. If HIV uses the CCR5 coreceptor on the surface of the a CD4 cell it is called R5-tropic. If it uses …

treatment-naive – someone who has never taken any anti-HIV treatments before. (Note: people who are treatment naive can still be resistant to anti-HIV drugs if they were infected with a drug resistant strain of HIV}.

treatment-experienced – someone who has previously used anti-HIV treatments.

second-line therapy – the combination of used after your first treatment has failed.

salvage therapy – a term for the combination therapy used after someone has developed resistance to three or more classes of HIV drugs. Also called ‘third-line’ or ‘rescue therapy’ or ‘treatment of patients with multidrug resistance’.

mega-HAART – a term for a drug combination that uses five or more HIV drugs, usually including 2–3 protease inhibitors. Rarely used now.

genome – term for the complete genetic material (RNA or DNA) of any organism.

fold-change – a term relating to drug resistance after a phenotype resistance test. 4-fold resistance (also called a 4-fold loss in sensitivity) means you need to use four times the dose to get the same reduction in viral load.

expanded access programme (EAP) – a scheme that allows people to access a drug before it has been approved (but when approval is expected). EAPs are for people urgently need treatment as a life-saving option and who do o have …

confirmatory test – a second test to double-check the results of a previous one. For example, if your viral load is usually undetectable and then becomes detectable, you need a second confirmatory test. This is to check that the detectable …

base – (also called nucleotide) – the building blocks in DNA that form amino acids. There are four bases represented by the letters A (adenine), T (thymine), C (cytosine) and G (guanine). In RNA the T is replaced by U …