I kliniske, kontrollerede undersøgelser oplevede 19, 4% af patienterne symptomer fra nervesystemet i moderat til svær grad sammenlignet med 9, 0% af de patienter, der fik kontrolregimer.
Nervous system symptoms with efavirenz: in clinical controlled studies, nervous system symptoms of moderate-to-severe intensity were experienced by 19.4% of patients compared to 9.0% of patients receiving control regimens.