Toxicology
Piperazines
Mechanism of action/toxicity: enhances neurotransmitter release and reuptake inhibition of dopamine,
serotonin, and norepinephrine release (Emerg Med Clin North Am 2014;32:1-28)
Predominantly euphoria and increased energy
Common adverse effects include:
Psychiatric: Agitation, anxiety, hallucinations, psychosis, depressed mood or mood swings,
paranoia
ii.
Neurologic: Confusion, insomnia, tremor, seizures, dizziness, headache
iii.
Cardiovascular: Angina, hypertension, tachycardia, palpitations, QT prolongation
iv.
GI: Abdominal pain, nausea, vomiting
Renal: Urinary retention
Treatment
Mostly supportive care with intravenous fluid administration
Benzodiazepines for agitation or seizures
Avoid antipsychotics because of the risk of worsening hyperthermia, extrapyramidal effects, and
hypotension or arrhythmias.
| d. | Treat hypertension with parenteral antihypertensives or clonidine. |
|---|
Hyperthermia treatment if above 104°F (40°C)
Monitor for serotonin syndrome.
Noncompetitive NMDA receptor antagonist (blocks glutamate and aspartate)
Mild to moderate blockade of catecholamine reuptake
Predominantly hallucinations and vivid dreams
Common adverse effects include:
Psychiatric: Impaired memory, cognitive dysfunction, severe agitation
ii.
Cardiovascular: Hypertension, tachycardia, cardiac arrhythmias
iii.
Respiratory: Laryngospasm, apnea, respiratory depression
iv.
GI: Anorexia, nausea, vomiting
Genitourinary: Cystitis, irritable bladder, urethritis
Treatment
Mostly supportive care with intravenous fluid administration
Monitor for rhabdomyolysis
ii.
Aspiration precautions are recommended in comatose patients
iii.
Urinalysis and serum chemistries if symptomatic for cystitis
Activated charcoal may provide benefit if given within 1 hour of oral ingestion. Additional doses
every 4 hours may be considered.
Benzodiazepines are recommended for agitation (eg, short-acting agents such as midazolam) or
seizures (eg, lorazepam per standard status epilepticus management).
| d. | Haloperidol may be used if benzodiazepines are not effective. Monitor closely because of the |
|---|
potential of lowering the seizure threshold and worsening of dystonia, hypotension, neuroleptic
malignant syndrome, and/or myoglobinuria.