Principles of clinical pharmacology in postexposure prophylaxis

Deciding on postexposure prophylaxis for any infection requires that the patient and healthcare provider understand the magnitude of infection risk and the adverse consequences of therapeutic intervention or nonintervention. Principles of epidemiology and microbiology allow us to estimate the risk of infection. Principles of clinical pharmacology allow us to estimate the risk and benefit of therapy. The dose-response-time relationships for antiviral activity and toxicity of a drug can be used to develop regimens that maximize benefit and minimize risk. Other important pharmacologic considerations include the role of active and toxic drug metabolites, combination chemotherapy, drug interactions, and medication compliance.