Given risk of rhabdomyolysis with use of these agents, testing should include creatine kinase, renal function tests, and a U/A in patient with clinical symptoms of intoxication If tests for muscle enzymes and/or renal function are abnormal and the urine has a positive test for hemoglobin without red blood cells, the patient should be assumed to have rhabdomyolysis and should be treated accordingly (see Chapter 100 Renal and Electrolyte Emergencies ) Although urine acidification (pH less than 5.0) enhances the urinary excretion of PCP, it should not be performed because it exacerbates metabolic acidosis and may promote deposition of myoglobin in renal tubules Hallucinogens: LSD, Psilocybin, Mescaline, and Tryptans CLINICAL PEARLS These drugs can produce a number of mental status changes, including hallucinations, delusions, and paranoid ideation Patients may sustain significant injuries while under the influence of these drugs, thus careful assessment for secondary injuries is warranted No single characteristic distinguishes hallucinogens from other classes of centrally active drugs such as anticholinergics, cocaine, and amphetamines However, the psychedelic state is characteristically described as consisting of vivid and unusual visual experiences with diminished control over what is experienced Images and sensations take on profound meaning, and the ability to differentiate oneself from the environment is decreased Most drugs in this category are related to the indolealkylamines (psilocybin, dimethyltryptamine [DMT], diethyltryptamine), lysergamides (LSD), or phenylethylamines (mescaline, methylenedioxymethamphetamine [MDMA, Ecstasy, Molly], synthetic cathinones, the 2C class of drugs) Current Evidence Hallucinogens act at multiple sites in the CNS The “2C” drugs (4-iodo-2,5-dimethoxyphenylethylamine and 4-iodo-2,5-dimethoxy-N -(2methoxybenzyl) phenethylamine) are hallucinogenic phenethylamines initially developed for research purposes that have subsequently emerged as drugs of abuse The pharmacologic action that these drugs seem to have in common is as agonists of presynaptic serotonin-2 receptors (which modulate serotonin release into the synaptic cleft) Most of these agents have structural similarities to