Hallucinogen Toxicity Clinical Presentation

Although most patients who present to the ED with hallucinogen intoxication have a history of recent ingestion, not all are diagnosed easily.^[7]

Consider possible hallucinogen ingestion in patients with acute psychotic behavior and attempt to trace the onset and causes of the behavior.

A history of previous hallucinogen abuse may indicate acute ingestion, flashback behavior, or psychotic break caused by the abuse.

Make an effort to screen patients for other potential exposures or ingestions as well as infectious, traumatic, or other underlying etiologies of the behavior.

Question family, friends, and prehospital care personnel closely for clues to possible etiology of the behavior.

Lysergic acid diethylamide

Patients presenting for ED care are generally those for whom the hallucinogenic experiences have become uncomfortable (ie, "bad trips") or those who have become injured or appear at risk for self-injury because of their behavior. Initial evaluation may reveal a patient who is agitated and psychotic.

The patient may be confused or disoriented, display distorted perceptions and impaired judgment, and have impaired concentration and intellectual functions. Physical examination may reveal mydriasis, tachycardia, and tachypnea without any other significant physical findings. Examine the patient thoroughly for traumatic injuries and the possibility of other etiologies, such as CNS infections or other acute intoxication. Laboratory evaluation may include urine drug assays, urinalysis, and blood glucose. Perform additional testing if etiology of the behavior is in doubt.

Phencyclidine and ketamine

Individuals who ingest these substances often have been found in bizarre situations or have placed themselves in danger. The dissociative properties of these drugs allow the abusers to believe they are outside of their body, and the anesthetic properties prevent normal pain feedback mechanisms that usually limit physical activity.

Individuals with significant intoxication can sustain tremendous and even life-threatening injuries without perceived pain. They often fluctuate from combative and anxious to sedated and somnolent. Patients generally have mixed nystagmus, comprising horizontal, vertical, and rotatory. Rotatory nystagmus strongly suggests PCP intoxication.

Most patients have mild-to-moderate hypertension and approximately one third have tachycardia. Confusion, altered perceptions, visual hallucinations, and significant violent or self-destructive behavior may occur. The period of psychotic behavior may be prolonged, with episodes of severe depression and schizophrenia.

Psilocin and psilocybin

The most common effects are perceptual distortions or hallucinations. Hallucinations are generally visual but other types may occur. Some patients experience euphoria and tachycardia, and most patients have some mydriasis. Hyperreflexia, anxiety, and drowsiness may occur.

Some species of toxic mushrooms may cause adverse GI reactions, including cramping, nausea and vomiting, and diarrhea. Always consider the possibility of toxic mushroom ingestion in patients presenting with a history of mushroom use.

Mescaline

Initial responses include agitation, diaphoresis, and abdominal cramping with nausea and vomiting. Initially, mildly elevated blood pressure with reflex bradycardia and mildly elevated body temperature may occur. Larger ingestions can produce hypotension and respiratory depression. Often the individual ritualistically collects and re-ingests the vomited material to maximize the hallucinogenic effect. These adverse effects generally persist for only 1-2 hours.

Feelings of euphoria and associated hallucinations generally begin 2-4 hours postingestion. The sympathomimetic effects may persist throughout the intoxication. Hallucinations are mostly visual, but all forms may occur. A sense of expansion of self and tremendous power has been described, with associated intense visual images in bright colors and geometric patterns. Adverse perceptions of self, anxiety, and depression can occur. The intoxication generally lasts 6-8 hours and usually is followed by somnolence.

Patients presenting after mescaline ingestion often complain of the sympathomimetic effects and GI distress associated with the ingestion. Although physical injury can occur because of the dysphoria and sense of power, this is less common than with PCP.

Designer drugs

The amphetamine -derived designer drugs all have sympathomimetic effects that account for the adverse effects (eg, hypertension, tachycardia, hyperthermia).^[8] Hyperthermia may be the most serious adverse effect, and it may be compounded by the use as "club drugs" or at "raves" where use is associated with prolonged dancing and dehydration. The prolonged dancing or other physical activity may contribute to the severe hyperthermia that has been described, and this as well as the dehydration may contribute to associated rhabdomyolysis^[9] and renal failure. Hypertensive crisis has also been described.

Effects last from a few hours to as long as 24 hours for drugs like AMT.

Seizures may occur.

• Patient presentations may vary from appearing anxious and agitated to somnolent or sedated.
• Mydriasis is often present, particularly with LSD use.
• Tachycardia, tachypnea, and mild-to-moderate elevation of blood pressure often are noted.
• Temperature generally is normal, but a patient experiencing episodes of extreme exertion, combative behavior, or infection may present with hyperthermia.
• The neurologic examination should be nonfocal, with varying degrees of cognitive distortions or deficits.
• Traumatic injuries may be present and may be caused by the altered perceptions of reality or combative or destructive behavior.