Situations That Require Special Consideration
Resistance of the Source Virus to Antiretroviral Drugs
It is unknown whether drug resistance influences transmission risk; however, transmission of drug-resistant HIV has been reported and is therefore a theoretical concern when choosing PEP regimens. If the source-person's virus is known or suspected to be resistant to one or more of the drugs included in the PEP regimen, the selection of drugs to which the source person's virus is unlikely to be resistant is recommended. If the resistance is to one class of antiretroviral drugs, the addition to the basic PEP regimen of a drug from another class might be considered (e.g., addition of a PI when a source patient has not been treated with a PI but has virus resistant to one or more NRT's). It is strongly recommended that PEP be started regardless of the resistance status in the source virus; if resistance is known or suspected, a third or fourth d rug may be added to the regimen until consultation with a clinical expert in the treatment of HIV infection or disease can be obtained.