PROTEASE
INHIBITORS (PIs)
Protease Inhibitors: Antiviral drugs that act by
inhibiting the virus protease enzyme, thereby preventing viral replication.
Specifically, these drugs block the protease enzyme from breaking apart long
strands of viral proteins to make the smaller, active HIV proteins that comprise
the virion. If the larger HIV proteins are not broken apart, they cannot
assemble themselves into new functional HIV particles.
|
Drug |
Dose |
Common Side Effects/Comments |
|
Amprenavir
Agenerase |
1200 mg (8 cap) twice daily * |
Rash (20%) |
|
Atazanavir
Reyataz® |
400mg
(2 cap) once a day with food
|
Increased
bilirubin levels - levels return to normal after a few days in most cases
|
|
Indinavir
Crixivan |
800 mg (2 cap) every 8 hours on empty
stomach or with snack containing <2 g of fat * |
Kidney stones in 6%-8%: good hydration
essential. Occasional nausea and GI upset. Store in original container
which contains desiccant; without this, IDV is only stable for about 3
days |
|
Lopinavir/Ritonavir
Kaletra |
Coformulated lopinavir 400 mg + ritonavir
100 mg (3 cap) twice daily with food |
GI side effects common but mild.
hyperlipidaemia. |
|
Nelfinavir
Viracept |
1250 mg (5 tab) twice daily or 750 mg (3
tab) 3 times daily with food |
Diarrhoea common; occasional nausea |
|
Ritonavir
Norvir |
600 mg (6 cap) twice daily; start with 300
mg twice daily and increase to full dose over 14 days |
Nausea, diarrhoea, numb lips; occasional
hepatitis; hyperlipidaemia. Store capsules in refrigerator. Stable at room
temperature for up to 1 month. Used at lower dosages as pharmacokinetic
enhancer of other protease inhibitors |
|
Saquinavir
(Soft Gel Formulation)
Fortovase |
1600 mg (8 cap) twice daily or 1200 mg (6
cap) 3 times daily with fat-containing food (>28 g) * |
Soft gel formulation with improved
absorption replacing hard gel (Invirase). Storage in the fridge. Stable wt
room temperature for up to 3 months. |
|
Dual & Boosted
PI |
Combinations
the
most used doses - individual monitoring (TDM) of drug levels is
recommended |
|
|
indinavir/ritonavir |
400mg/400mg
1xIDV
/ 4xRTV twice daily |
|
|
indinavir/ritonavir |
800mg/200mg
2xIDV
/ 2xRTV, twice daily |
|
|
indinavir/ritonavir |
800mg/100mg
2xIDV
/ 1xRTV, twice daily |
|
|
saquinavir/ritonavir |
400mg/400mg
2xSQV
/ 4xRTV, twice daily |
food
reduces side effects
Invirase,
hard gel formulation of saquinavir can be used instead of Fortovase soft
gel capsule when using ritonavir. Invirase is a smaller pill with less
side effects |
|
saquinavir/ritonavir |
1000mg/100mg
5xSQV
/ 1xRTV, twice daily |
food
reduces side effects |
|
fosamprenavir/ritonavir |
700mg/100mg
1xFosAPV
/1xRTV, twice daily (once-daily possible) |
|
|
atazanavir/ritonavir |
300mg/100mg
2xATV/
1 x RTV, once daily |
|
