Gamma hydroxybutyrate toxicity: Difference between revisions
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*Look for co-ingestants and occult trauma | *Look for co-ingestants and occult trauma | ||
*Charcoal not helpful since rapidly absorbed; patients may vomit and are at risk for aspiration | *Charcoal not helpful since rapidly absorbed; patients may vomit and are at risk for aspiration | ||
*Protein bound so can use dialysis | *Protein bound so can use dialysis but so short course usually do not need. | ||
===Antidotes=== | ===Antidotes=== | ||
*[[ | *[[Flumazenil]]/ [[Narcan]] helps in animals but not in humans{{Citation needed|reason=Reliable source needed|date=January 2021}} | ||
*[[ | *[[Physostigmine]] may reverse coma, but if co-ingestant present, may be dangerous-potential to lower [[seizure]] threshold | ||
==Disposition== | ==Disposition== | ||
*May consider discharge if symptoms improve after observation for several hours | |||
*Consider admission if symptoms do not improve or worsen | |||
==See Also== | ==See Also== | ||
Latest revision as of 16:53, 24 April 2021
Background
- Abbreviation: GHB
- Frequently referred to as the "date rape drug"
- Central nervous system depressant
- GABA-B agonist (as opposed to GABA-A agonists - alcohol, benzodiazepines, etc)
- Abused for:
- Body building or sleep enhancement
- euphoric, sexual, stimulant, and relaxant effects
- Surreptitious drugging to facilitate sexual assault
- Also used therapeutically in the treatment of narcolepsy[1]
Pharmacokinetics
- Effects start in 15-20 minutes, peak in 30-60 minutes,
- Lipid soluble, readily crosses the blood brain barrier
- Elimination is dose-dependent; half-life of 20-50 minutes
- The duration of GHB's clinical effects depends upon the dose, and ranges from 2.5-4 hours
Pharmacology
- Is a metabolite and precursor of GABA
- Interacts with GHB-specific receptors and also acts as a direct agonist of GABA-B receptors
- Affects multiple neurotransmitter systems, including those of opioids, dopamine, serotonin, glutamate, and acetylcholine
- Gamma butyrolactone (GBL) and 1,4 butanediol (BD) are GHB analogs that are rapidly metabolized to GHB after ingestion, with the same toxic and recreational effects
Clinical Features
Classic Presentation: Young adult presents comatose and is intubated for airway protection and subsequently awakens while in the emergency department. When awake, typically can be safely discharged.
- CNS depression; ataxia, nystagmus, somnolence, seizure, coma
- EEG may show no epileptiform changes
- Respiratory depression; may also alternate between periods of apnea and hyperventilation
- Worse with other CNS depressants (alcohol, benzodiazepines, etc)
- Bradycardia, hypotension; ECG changes are rare
- Nausea and vomiting GI symptoms
- Hypothermia
- Often found to have co-intoxicants
- Usually young white male from nightclub
- CNS and respiratory depression can resolve abruptly within minutes
- Patients may become aggressive upon waking
Clinical Course
- Recover in 2-6 hours
- May be extubated and sent home
- If longer than 6 hours, look for other cause
- Can have cross tolerance with other drugs-alcohol and others that effect liver p450 cytochrome oxidase system
Differential Diagnosis
Sedative/hypnotic toxicity
- Absinthe
- Barbiturates
- Benzodiazepines
- Chloral hydrate
- Gamma hydroxybutyrate (GHB)
- Baclofen toxicity
- Opioids
- Toxic alcohols
- Xylazine toxicity
Drugs of abuse
- 25C-NBOMe
- Alcohol
- Amphetamines
- Bath salts
- Cocaine
- Ecstasy
- Gamma hydroxybutyrate (GHB)
- Heroin
- Inhalant abuse
- Hydrocarbon toxicity
- Difluoroethane (electronics duster)
- Marijuana
- Kratom
- Phencyclidine (PCP)
- Psilocybin ("magic mushrooms")
- Synthetic cannabinoids
- Chloral hydrate
- Body packing
Diagnosis
- Not detectable on rapid urine drug screens
- Definitive diagnosis requires gas chromatography
- ED physicians are not accurate in diagnosing clinically
Management
- Supportive
- Look for co-ingestants and occult trauma
- Charcoal not helpful since rapidly absorbed; patients may vomit and are at risk for aspiration
- Protein bound so can use dialysis but so short course usually do not need.
Antidotes
- Flumazenil/ Narcan helps in animals but not in humans[citation needed]
- Physostigmine may reverse coma, but if co-ingestant present, may be dangerous-potential to lower seizure threshold
Disposition
- May consider discharge if symptoms improve after observation for several hours
- Consider admission if symptoms do not improve or worsen
See Also
References
- ↑ Mamelak M, Scharf MB, Woods M. Treatment of narcolepsy with gamma-hydroxybutyrate. A review of clinical and sleep laboratory findings. Sleep. 1986;9(1 Pt 2):285-289. doi:10.1093/sleep/9.1.285