Approach to hallucinogen, inhalant, and cannabis use, intoxication, and overdose: Clinical sciences

Acute hallucinogen, inhalant, or cannabis intoxication causes a temporary state of altered consciousness as well as behavioral and psychological changes, impaired judgment, and physiological disturbances. These psychoactive recreational substances alter neurotransmitters and receptors within the central nervous system to produce various effects, including euphoria, distorted perceptions and thoughts, and sedation or psychomotor agitation.

Okay, if a patient presents with a chief concern suggesting hallucinogen, inhalant, or cannabis use, intoxication, or overdose; first perform an ABCDE assessment to determine if they are stable or unstable. If unstable, stabilize their airway, breathing, and circulation; and perform endotracheal intubation if your patient demonstrates shallow or ineffective respirations. Next, obtain IV access and consider starting IV fluids. Then, put your patient on continuous vital sign monitoring, pulse oximetry, and cardiac telemetry; and provide supplemental oxygen if needed. Additionally, if your patient is hyperthermic, provide cooling blankets; and if they are agitated, consider sedation.

Here’s a clinical pearl to keep in mind! Patients with significant hallucinogen, inhalant, or cannabis exposure may present with overdose, which may cause hemodynamic instability, severe psychosis, seizures, or even coma. Additionally, individuals with acute inhalant intoxication can develop life-threatening cardiac dysrhythmias requiring resuscitative measures.

Here’s a high-yield fact! 3,4-Methyl enedioxy methamphetamine, also known as MDMA, is a commonly abused recreational substance with serotonergic properties. Excessive ingestion can result in serotonin syndrome, characterized by elevated blood pressure; increased heart rate; myoclonus; hyperreflexia; diaphoresis; and seizures. If you suspect serotonin syndrome, immediately discontinue the offending substance and any serotonergic medications your patient might be taking.

Now that we’ve addressed unstable patients, let’s return to the ABCDE assessment and look at stable ones. First, obtain a focused history and physical exam. Since individuals with acute intoxication usually present with an altered mental state, you may need to rely on caregivers, family members, and friends to provide details. History typically reveals recent recreational substance use, with acute changes in mood and behavior. The physical exam may demonstrate abnormal blood pressure, heart rate, and respiratory rate.

Neurologic exam might also demonstrate impaired memory, slurred speech, and poor coordination. These findings should make you consider the possibility of hallucinogen, inhalant, or cannabis intoxication; so as a next step, take a close look at your patient’s clinical picture to assess the causative substance.

Here’s another clinical pearl! While characteristic signs and symptoms can often help you identify the substance responsible for intoxication, you may need to perform urine drug screening or other testing for confirmation.

Let’s start by looking at hallucinogens, which include MDMA; phencyclidine, or PCP; and lysergic acid diethylamide, or LSD.

First up is MDMA, which is also called ecstasy or molly. MDMA is usually taken orally, and it produces stimulant and hallucinogenic effects that are caused by increased serotonin, dopamine, and norepinephrine release.

Patients with MDMA intoxication typically present with euphoria, agitation, and increased social empathy. They often have a distorted perception of time and experience enhanced visual, auditory, olfactory, gustatory, and tactile sensations.

Physical exam typically reveals mydriasis, or dilated pupils; trismus, or jaw muscle rigidity; and bruxism, or grinding of the teeth. These findings are consistent with MDMA intoxication.

Here’s another high-yield fact! MDMA causes excessive antidiuretic hormone secretion, which stimulates thirst and prompts increased water intake. Ingestion of hypotonic fluids can potentially lead to significant hyponatremia, even after a single dose of MDMA.

Next up is phencyclidine, or PCP; which is commonly known as angel dust, hog, elephant tranquilizer, and peace pill. This hallucinogen is typically taken by mouth, snorted, or injected; but some individuals spray it on tobacco or cannabis and smoke it. PCP inhibits the reuptake of dopamine, serotonin, and norepinephrine; and it antagonizes NMDA receptors, leading to both stimulant and depressive effects.

Patients with PCP intoxication often present with memory and speech impairment, in addition to violent, impulsive, and agitated behavior. They also may describe synesthesia, a phenomenon in which an individual can “taste” sounds and words and “hear” colors.

Physical exam often reveals abnormal vital signs, such as elevated blood pressure, increased heart rate, and hyperthermia. Because these individuals experience decreased pain sensation, you may notice signs of physical injury.

Other common exam findings include muscle rigidity, horizontal or vertical nystagmus, which refers to rapid side-to-side or up-and-down eye movements; hyperacusis, or sensitivity to loud noises; and miosis, or constricted pupils. These findings are highly suggestive of PCP intoxication.

Alright, now let’s switch our focus to lysergic acid diethylamide, or LSD. When ingested, LSD acts as a serotonin 2A receptor agonist and increases serotonin concentrations in the synaptic cleft, which can result in hallucinations.