Here is the information from Wiki about GHB:
In humans, GHB has been shown to inhibit the elimination rate of alcohol. This may explain the respiratory arrest that has been reported after ingestion of both drugs.[32] A review of the details of 194 deaths attributed to or related to GHB over a ten-year period found that most were from respiratory depression caused by interaction with alcohol or other drugs.[33]
Reported deaths[edit]
One report has suggested that sodium oxybate overdose might be fatal, based on deaths of three patients who had been prescribed the drug.[34] However, for two of the three cases, post-mortem GHB concentrations were 141 and 110 mg/L, which is within the expected range of concentrations for GHB after death, and the third case was a patient with a history of intentional drug overdose.[35]
One publication has investigated 226 deaths attributed to GHB.[36] Of 226 deaths included, 213 suffered cardiorespiratory arrest and 13 suffered fatal accidents. Seventy-one deaths (34%) had no co-intoxicants. Postmortem blood GHB was 184400 mg/L (median=347) in deaths negative for co-intoxicants.
GHB is produced in the body in very small amounts, and blood levels may climb after death to levels in the range of 3050 mg/L.[37] Levels higher than this are found in GHB deaths. Levels lower than this may be due to GHB or to postmortem endogenous elevations.
A UK parliamentary committee commissioned report found the use of GHB to be less dangerous than tobacco and alcohol in social harms, physical harm and addiction.[
It seems pretty easy to cause an overdose and fatality especially when mixed with alcohol. So how did this not happen with all the supposed victims of Cosby?