Levels of the recreational drug commonly known as GHB (gamma hydroxybuytrate) may be increased to life-threatening levels if it is taken alongside a protease inhibitor. In a report from Seattle a 29 year-old man receiving treatment with ritonavir and saquinavir became unconscious after taking half a teaspoonful of GHB. He had taken a previous half teaspoonful of GHB and two ecstasy tablets in the preceding 24 hours. The man had not experienced adverse reactions to GHB or ecstasy prior to protease inhibitor treatment. Reporting doctors suggested that ritonavir and saquinavir slowed down metabolism of both drugs and caused the near-fatal reaction.

It is now suggested that GHB used with HAART it could lead to a 2-3 fold build up in blood. The possible symptoms of GHB overdose include vomiting, breathing problems, seizures, stupor and coma, and the dose normally associated with severe distress is greater than 50mg/kg of body weight. In this case the dose has been estimated at less than 10mg/kg body weight (Harrington 1999).