Psychoactive Drugs: Effects on the Nervous System
In the nervous system, psychoactive drugs can significantly alter brain function.
CNS Depressants
CNS Depressants slow down the functioning of the brain, leading to a numbing effect. Examples include alcohol and tranquilizers.
Stimulants
Stimulants accelerate brain function.
- Major Stimulants: Cocaine base, cocaine, and amphetamines.
- Minor Stimulants: Nicotine and caffeine.
Hallucinogens
Hallucinogens alter cerebral operation, causing perceptual distortions. Examples include marijuana, LSD, and ecstasy.
Action in the Body
Alcohol: Affects synapses by interacting with receptors such as GABA, an important inhibitory neurotransmitter, resulting in a sedative effect. Alcohol is a depressant.
Marijuana: Leads to confusion, altered memory and perception, and motor incoordination. Marijuana is a hallucinogen.
Caffeine: Binds to receptors in the CNS, potentially causing sleep disorders and increased heart rate. Caffeine is a stimulant.
Morphine: Binds to receptors involved in pain pathways, reducing pain. Morphine is a depressant.
“Viaggio”: Affects dopamine reuptake, altering the perception of pleasure and potentially leading to disorders, anxiety, and aggressiveness. “Viaggio” is a depressant.
Amphetamine: Increases the release of dopamine, leading to a feeling of being awake and alert.
LSD: Causes alterations in the perception of the world and personal excitation of the CNS. LSD is a hallucinogen.
Effects on Chemical Synapses
- “Viaggio” inhibits the reuptake of neurotransmitters.
- Morphine inhibits neurotransmitter release.
- Uppers increase the liberation of neurotransmitters and inhibit their reuptake.
Cocaine: Immediate effects include accelerated heart rate, increased blood pressure, body temperature, and sweating. Long-term effects include memory loss, anxiety attacks, respiratory problems, and nutritional disorders.
Heroin: Immediate effects include euphoria, skin flushing, and dry mouth. Long-term effects include collapsed veins, pulmonary complications, coma, or death.
Marijuana: Immediate effects include eye redness, euphoria, increased heartbeat, confusion, and altered perception.
Addiction, Tolerance, and Dependence
Addiction: An uncontrollable desire to continue using drugs.
Tolerance: Cellular adaptation to a substance, requiring increased consumption to achieve the initial effect.
Dependence: The need to continue consuming a substance to avoid withdrawal symptoms. It can be physical or psychological, with the latter involving a sense of satisfaction and a desire to repeat the effect or avoid discomfort.
Protein Binding and Stereoisomers
- Protein-bound drugs have a temporary or reversible union.
Stereo-specific (SS) union: Recognizes the spatial orientation of atoms in a molecule.
Stereoisomers: Molecules with identical structure and composition, differing only in spatial orientation.
Agonists: Increase the activity of enzymes or other proteins.
Antagonists: Inhibit the activity of enzymes or other proteins.
Antibiotics, Diuretics, and Psychopharmaceuticals
Antibiotics: Alter bacterial metabolism and inhibit protein synthesis to combat bacterial diseases.
Diuretics: Promote water elimination.
Psychopharmaceuticals: Affect brain function and mental states. Some can be abused, leading to compulsive consumption and drug dependence. For example, alcohol abuse can create drug addiction.
Cocaine’s Mechanism of Action
Cocaine inhibits the recycling mechanism of neurotransmitters called biogenic amines (noradrenaline, dopamine, serotonin). It blocks the intraneuronal transport of these amines, leading to increased synaptic concentration and increased cerebral excitability.
Mechanisms of Psychopharmaceutical Action
Increased neuronal excitability can occur by blocking inhibitory synapses or stimulating excitatory synapses. The inhibitory action of psychopharmaceuticals is achieved by increasing the activity of inhibitory synapses or blocking excitatory ones.
Alcoholism
Alcoholism can be hereditary.