D.
Common Combinations
Are chosen from 3 classes of drugs (see attached tables):
Nucleoside reverse transcriptase inhibitors (NRTIs)
Non-Nucleoside reverse transcriptase inhibitors (NNRTIs)
Protease inhibitors (PIs)
Common first and second line combinations are
2
NRTIs + 1PI
2
NRTIs + NNRTI
But watch for drug interaction that increase the risk of toxicity or
make the treatment less effective:
Therefore do not use
d4T
& ddC
causes peripheral neuropathy
d4T
& ddI & Hydroxyurea
increased risk of pancreatitis
AZT&
d4T
effects cancel each other out
3TC
& ddC
Nevirapine
& saquinavir
Always watch other drugs patient may be taking: these may increase or
reduce breakdown of HIV drugs by the liver causing treatment failure or toxicity
Especially: rifampicin
and rifabutin
E. Monitoring therapy
3 Monthly:
FBC
Biochemistry including amylase, lipids, glucose
CD4
? Resistance assay at baseline and if
treatment fails
F. Compliance with treatment
HAART will only work if the patient takes it!
Everyone who takes pills for a long time misses doses (called
non-compliance)
In the USA and Europe patients typically miss about 50% of their
prescribed doses of any medication although this may be lower for HAART
If patients miss <5% of their doses, HAART
fails in 20% at 6 months
If patients miss 5-10% of their doses, HAART
fails in 55% at 6 months
If patients miss >30% of their doses, HAART
fails in 82% at 6 months
The
patient should not be told off for being non-compliant – it is just normal
human behaviour
How
can non-compliance be reduced? Some ideas:
·
Before starting treatment ensure the patient wants to take treatment and
understands how to take it and the reasons why doses should not be missed
·
Involve patients in planning a treatment combination that fits into
their daily routine
·
Warn patients about common side effects and offer treatment for them if
they occur
·
Encourage patients to see the risk of treatment failure (AIDS related
illness and death)
·
Show the beneficial effects of regular dosing on their blood tests