12.5
Estimulantes del sistema nervioso central: agentes psicodélicos
Los alucinógenos, también conocidos como drogas psicodélicas, son una clase de sustancias conocidas por su capacidad para alterar la percepción, la co…
Las drogas psicodélicas o alucinógenos son sustancias no adictivas que alteran la percepción, la cognición y las emociones.
Activan el receptor 5-HT2A del cerebro, que se acopla a la proteína Gq, generando IP3 y, en última instancia, conduce a la liberación de calcio intracelular.
Los alucinógenos se clasifican en dos clases principales en función de su estructura química distintiva.
Las indoleaminas incluyen agentes como el LSD y la psilocibina. Inducen distorsiones sensoriales, alucinaciones y estados alterados de conciencia.
Las fenetilaminas incluyen agentes como MDMA, mescalina y PCP.
La MDMA, conocida como éxtasis o molly, proporciona efectos estimulantes y psicodélicos, provocando sentimientos de empatía y euforia.
La PCP —desarrollada inicialmente como anestésico— provocaba retraimiento emocional y agresividad en dosis altas.
Aunque los alucinógenos no causan dependencia física, el desarrollo rápido de tolerancia requiere monitoreo de drogas o intervención médica. Esto implica tranquilizar al paciente, administrar diazepam en caso de agitación severa o soporte vital para la sobredosis de PCP.
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Q1: How do psychedelic drugs affect the brain at the molecular level?
Psychedelic drugs activate the brain's 5-HT2A receptor, which couples to Gq-type G proteins. This triggers a biochemical cascade that releases intracellular calcium, producing the drugs' distinctive psychological effects. This mechanism underlies the altered perception, cognition, and emotions characteristic of hallucinogens.
Q2: What are the main chemical classes of hallucinogens?
Hallucinogens divide into two classes: indoleamines and phenethylamines. Indoleamines include LSD and psilocybin, producing vivid visual effects and altered consciousness. Phenethylamines include MDMA and PCP, with MDMA providing both stimulant and psychedelic effects, while PCP was originally developed as an anesthetic.
Q3: Why are psychedelic drugs considered non-addictive?
Psychedelic drugs do not cause physical dependence, distinguishing them from many other abused substances. However, rapid tolerance develops with regular use, requiring higher doses to achieve the same effects. While withdrawal symptoms can occur in some users, the absence of physical dependence classifies these drugs as non-addictive.
Q4: What are the distinct effects of MDMA compared to other hallucinogens?
MDMA, known as ecstasy or molly, uniquely provides both stimulant and psychedelic effects. It elicits feelings of empathy, euphoria, and heightened sensory perception. Unlike indoleamines that primarily produce visual distortions, MDMA's dual action creates a distinctive emotional and sensory experience.
Q5: How does PCP differ from other phenethylamines in its effects?
PCP, initially developed as an anesthetic, causes emotional withdrawal and aggressive behavior at high doses. Unlike MDMA, which produces empathy and euphoria, PCP's effects are primarily negative and potentially dangerous. Its anesthetic origins distinguish it chemically and functionally from other phenethylamines.
Q6: What medical interventions are used for hallucinogen overdose or severe reactions?
Treatment involves patient reassurance and administering diazepam for severe agitation. In cases of PCP overdose, life support may be necessary. These interventions address the rapid tolerance and acute psychological effects that can occur, though hallucinogens lack the physical dependence seen in drug abuse and addiction pharmacological phenomena.
Q7: What sensory and psychological effects do indoleamine hallucinogens produce?
Indoleamines like LSD and psilocybin induce sensory distortions, hallucinations, and profoundly altered states of consciousness. These drugs produce vivid visual effects and perceptual changes. Regular use leads to rapid tolerance, requiring higher doses to achieve the same psychological and sensory effects.