L40 Drugs of Abuse and Drug Dependence →↑↓ Flashcards
Classification of Additive Drugs (1)
Stimulants
→ Cocaine
→ Amphetamines
→ Nicotine, e.g. tobacco addiction
Depressants
→ Alcohol, e.g. alcohol addiction
→ Benzodiazepines
→ Barbiturates
Hallucinogens
→ LSD (lysergic acid diethylamide)
→ Methylenedioxymethamphetamine (MDMA; Ecstasy)
→ Mescaline
Mechanism, Contraindication, S/E of
Amphetamine (1)
→→AMPHETAMINE – a synthetic drug that stimulates nervous system (“uppers” or “speed”)
Triggers release and blocks reuptake of dopamine and norepinephrine
S/E
Nervousness, agitation, irritability confusion, paranoia, hostility Tolerance
Mechanism, Contraindication, S/E of
Cocaine
Acts on the reward system by preventing the reuptake of dopamine, resulting in a buildup of dopamine in the synapse
Adverse effects
→ Anxiety: hypertension, tachycardia, sweating, and paranoia
→ Stimulation of the CNS followed by a period of mental depression
→ Addicts withdrawal
→ Seizures
Mechanism, Contraindication, S/E of Nicotine
Mechanism of action
→ Low dose: ganglionic depolarization
→ High dose: ganglionic blockade
Adverse effects → Caner of the lungs, oral cavity, bladder, and pancreas → Obstructive lung disease → Coronary artery disease → Peripheral vascular disease
Depressants Alcohol
MoA
→ Related to changes in membrane fluidity with changes in membrane protein functions, i.e. causing inhibitory
postsynapitc potential (IPSP)
→ Enhancing the effects of GABA on GABAA receptors
→ Inducing the release of endogenous opioids
→ Altering the levels of serotonin and dopamine
→Alcohol Dependence (1) → Anxiety → Agitation → Hallucination → Convulsion → Insomnia → Muscle tremor → Elevated BP, pulse and temperature → Sweating
Synthetic Sedatives-Hypnotics Benzodiazepines
MAO:
positive modulators of the GABAA receptor-coupled chloride channels and increase response to GABA
Mechanism, Contraindication, S/E of Lysergic acid diethylamide (LSD) Hallucinogens
MOA: agonist at 5-HT2 receptors Adverse effects → Distressing anxiety → Fear of death → Nausea → Hyperreflexia → Tremor → Muscular weakness
Mechanism, Contraindication, S/E of Ecstasy (MDMA)
MOA: an indirect serotonergic agonist, increasing the amount of serotonin released into the synapse. MDMA acts on the serotonin transporter and is transported into the nerve terminal, which promotes release of serotonin.
S/E
“Serotonin syndrome
”→ Cognitive and behavioral changes: disorientation, hallucinations,
dizziness
→ Autonomic dysfunction: tachycardia, hypertension, flushing,
salivation, hyperthermia
→ Neuromuscular effects: muscle rigidity
→ Disseminated intravascular coagulopathy (DIC), renal failure, acute
respiratory distress syndrome (ARDS)
Acute symptomatic hyponatremia with the syndrome of inappropriate anti-duretic hormone secretion
→ “Flashbacks”
→ Parkinsonism
Drug-drug interaction: with monoamine oxidase (MAO)
inhibitors, other antipsychotic drugs
Mechanism, Contraindication, S/E of Dissociative Anesthetics (Ketamine)
MOA: acts by blocking activation of non-competitive N-methyl-D-aspartate (NMDA) receptors
→ a state of “dissociative anesthesia”
→ sensory loss, analgesia, amnesia but without actual loss of consciousness
Adverse Effects
⎼ Emergence reactions: common during recovery, include unpleasant dreams, confusion, hallucinations and irrational
behavior
→ “Out-of-body” state/experience: a psychological dissociation, “near death experience”
→“Flashback”
→Hyper- and hypotension, arrhythmias, brady- or tachycardia
→Respiratory suppression, apnoea
→ Long term effects: impaired memory, learning and attentional mechanisms; compulsive repeated use
→Drug-drug interactions: with other antipsychotic drugs
Mechanism, Contraindication, S/E of Dissociative Anesthetics Phencyclidine (PCP)
MOA: works by blocking the NMDA glutamate receptor to cause a series of hallucinogenic effects including euphoria, suicidal impulses and aggressive behavior
Adverse effects → Loss of balance → Slurred speech or trouble talking → Delusion → Convulsion → Paranoia
Mechanism, Contraindication, S/E of Cannabis Marijuana
Long-term effects → Decreased cognitive ability → Respiratory problems → Sterility / impotence → Psychosis
Tolerance and psychological dependence develop
→ Sleep disturbance
→ Loss of appetite, irritability
→ Tremor
Narcotics Analgesics
Opioids HEROIN →Euphoria →Mouth Dryness →Slowed breathing Codeine Methadone Used for eliminating an addicts desire for heroin