CNS Penetration Effectiveness (CPE) Score for Antiretroviral Drug Regimen

 

Issues pertinent to antiretroviral drug therapy:

(1) An HIV drug regimen consists of multiple drugs.

(2) Prevention and therapy of HIV-associated neurocognitive disorder requires effective control of the viral load in the central nervous system.

 

Each drug in a regimen can be characterized by how well it gets into the CNS.

Chemical Structure	Measureable Levels in CSF	Effect on CSF Viral Loads	Penetration Category
good penetration	at or above levels needed to control	good	1
fair	below levels needed to control	fair	0.5
poor penetration	none	poor	0

 

where:

• Assignment of the penetration category is based on 1 or more of the measures (OR applied).

• If a virus is resistant to a drug then inclusion of the drug in a regimen makes little sense.

• The score ignores synergy and antagonism.

 

CPE rank for a drug regimen =

= SUM(penetration categories for all drugs in the regimen)

 

Interpretation:

• minimum CPE rank: 0

• maximum CPE rank: number of drugs in the regimen

• A low CPE rank is associated with higher CNS viral loads and greater risk of a neurocognitive disorder.

• A CPE rank < 2 was associated with higher CSF viral loads.