No personal experience myself, but this is from Rosen's Emergency Medicine:
Withdrawal
Patients who suddenly stop GHB or its precursors after chronic, frequent use can experience a severe and potentially life-threatening withdrawal syndrome.50,58,59 Because of the short half-life of GHB, symptoms of withdrawal begin within several hours of the last
dose.
The typical patient will have been using these products for weeks or years, every 1 to 3 hours around-the-clock, to avoid withdrawal symptoms. Mild withdrawal is manifested with anxiety, tremor, and insomnia. This can progress to confusion, delirium, overt psychosis, paranoid ideation, hallucinations (visual, aural, or tactile), and autonomic instability. Diagnosis relies on a history of symptoms beginning after abrupt cessation of use of these products.
The differential diagnosis includes withdrawal from other sedatives or hypnotics, delirium tremens, sympathomimetic toxicity, serotonin syndrome, neuroleptic malignant syndrome, CNS infection, and thyroid storm. Initial treatment begins with high-dose benzodiazepines. However, GHB withdrawal may involve depleted levels of GABA.58 Because the effect of benzodiazepines requires the presence of GABA, they may not be effective in control of GHB withdrawal. Barbiturates, such as pentobarbital, which do not need GABA to be effective, are often required in cases of severe intoxication.60
These patients often require intensive care admission for aggressive sedation and to monitor fluctuating vital signs. Rhabdomyolysis and severe hyperthermia should be ruled out. Deaths have been reported, sometimes many days after presentation and after apparent improvement.58
Disposition
Because of GHB’s short half-life, symptoms often resolve while the patient is still in the ED. The patient generally regains consciousness spontaneously. No delayed toxicity is expected. Patients should be counseled about the seriousness of GHB intoxication.47
Key Concepts
Withdrawal from GHB or its precursors can be manifested with anxiety, tremor, and insomnia but can progress to a severe syndrome characterized by delirium and autonomic instability. Management of this syndrome often requires high-dose benzodiazepines or barbiturates.
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