Gamma-hydroxybutyrate can be found occurring naturally in many mammalian cells. In the brain, the highest amounts are found in the hypothalamus and basal ganglia (Gallimberti et al., 1989). It is likely that it is a neurotransmitter, although its precise role is unclear (Galloway et al., 1997). Closely linked to γ-aminobutyric acid (GABA), GHB is both a precursor and a metabolite of GABA (Chin et al., 1992).
With an extremely small therapeutic index, as little as double the euphorigenic dose of GHB may cause serious central nervous system depression. In recent years, it has been associated with numerous incidents of respiratory depression and coma, and an increasing number of deaths have been linked to GHB (Li et al., 1998).
The legal status of GHB is complicated. In 2001, GHB, which is classified as a Schedule III controlled substance, was given an FDA approvable letter with special regulations under the brand name Xyrem. It is available only from a single specialty pharmacy (Tunnicliff and Raess, 2002). Most of the GHB sold in the United States is of the bootleg variety, manufactured by nonprofessionals. In fact, it is relatively easy to manufacture, and Internet Web sites devoted to explaining the process can be readily found. Of course, there is clever concealment and subterfuge in most of these sites.Physiological Effects of GHB
Ingested orally, GHB is absorbed rapidly and reaches peak plasma concentrations in 20 minutes to 60 minutes (Vickers, 1969). The typical dose is about a teaspoon, but the effects are dose dependent. The high lasts about three hours and reportedly has few lasting effects, but repeated use of the drug can prolong its effects.
Users of GHB report that it induces a pleasant state of relaxation and tranquility. A frequently reported effect is calmness, accompanied by loquaciousness. Like MDMA, GHB has also been described as a sensual drug. Its effects have been likened to alcohol(Drug information on alcohol), another GABA-like drug (McCabe et al., 1971). Users report a feeling of mild numbing and pleasant disinhibition, which accounts for the reports that GHB enhances the experience of sex. The dose-response curve for GHB is exceedingly steep. The LD-50 is estimated at perhaps only five times the intoxicating dosage (Vickers, 1969). Furthermore, the drug has synergistic effects with alcohol and other drugs. Therefore, small increases in the amount ingested may lead to significant intensification of the effects and to the onset of central nervous system depression. Coma and persistent vegetative states and death may result from overdose (Chin et al., 1992; Gallimberti et al., 1989; Takahara et al., 1977; Vickers, 1969).Mechanism of Action of GHB
The drug has several different actions in the CNS, and it has a variety of effects on dopamine(Drug information on dopamine) and growth hormone, as well as naturally occurring opiates (Galloway et al., 1997; Hechler et al., 1992). The consequences of these physiological changes are unclear, as are the overall health consequences for individuals who use GHB chronically.Treatment for GHB Abuse
linicians are advised to keep GHB in mind when confronting a patient with somnolence or loss of consciousness. In cases of acute GHB intoxication, physicians should provide physiological support and maintain a high index of suspicion for intoxication with other drugs. Most patients who overdose on GHB recover completely if they receive proper medical attention. A recent review suggested the following features for the management of GHB ingestion with a spontaneously breathing patient (Li et al., 1998):
If the patient's breathing is labored, they should be managed in the intensive care unit.