Cocaine and Psychostimulants PDF

Psychostimulants: Cocaine, amphetamines Dr Kaisan Mahadi Lecture outcomes Familiarize yourself with the common examples of psychostimulants Understand the mechanism of action for psychostimulants. Describe the side effects associated with psychostimulants abuse. CNS Stimulants Cocaine, Crack (...

Psychostimulants: Cocaine, amphetamines Dr Kaisan Mahadi Lecture outcomes Familiarize yourself with the common examples of psychostimulants Understand the mechanism of action for psychostimulants. Describe the side effects associated with psychostimulants abuse. CNS Stimulants Cocaine, Crack (free base or hydrochloride=Powder). D-Amphetamine, Methamphetamine, methylphenidate, phenmetrazine (Preludin) - used to treat obesity, (hallucinogens = MDA, MDMA, DOM; methylenedioxymethamphetamine, "ecstasy,"). Khat: Cathinone, methcathinone. Methylxanthines: caffeine (coffee), Theophylline used to treat asthma in the past (tea), theobromide (chocolate).  Cocaine Overview □Alkaloid from Erythroxylon coca plant. □Indigenous to western South America □Coca leaves used for religious, mystical, social, stimulant, and medicinal purposes □Main stimulant uses: endurance (athletes), feeling of well-being (euphoria) , alleviate hunger (for weight loss porpuses) □Medical uses: local anesthetic, vasoconstrictor (nasal congestion)  Cocaine Production □-Coca paste extracted from soaked and mashed leaves (60-80% cocaine) -Cocaine powder made by mixing paste with hydrochloric acid (cocaine HCl) -Freebase/crack extracted from powder with baking soda (smokable)  Amphetamine Overview (poor man’s cocaine bcs cheaper, crystal meth, ice, glass, speed) □Synthetic analog of ephedrine, active ingredient in mahuang □Mahuang used in China for asthma □Chinese (Mandarin) má huáng : má, hemp + huáng, yellow □Methamphetamine and Methylphenidate (Ritalin) are very similar □Medical uses: obesity, ADHD, narcolepsy Chemical Structure of Stimulants Neurophysiology: cocaine blocks the reuptake of norepinephrine so they stay at synaptic membrane. Subcutaneous, stays longer. Effects on Mind, Brain, Behavior Effects on Mind, Brain, Behavior (cont.) Peripheral Effects (sympathomimetic) Fight/Flight/Fright Syndrome Increase: (sympathetic nervous system Blood pressure. arousal) Blood sugar. Heart rate. -Cause of death is the heart because it affect AV node and cause Ventricular Irregular heart beat. tachycardia Vasoconstriction. Mechanism: Na channel blocker (mainly Body temperature Bronchodialation. cocaine) increase blood pressure, blood sugar, HR, Vasoconstriction, & Impaired breathing hyperthermic -Avoid BB because sympathomimetic affect alpha and beta receptors, B receptor will be blocked and alpha will become worse, hypertension will happen. -Dry skin: anticholinergic. -Sweaty: sympatho. Cocaine Cardiac Features □Cocaine dysrhythmias: Sodium and Potassium blockade. □Supraventricular tachycardia (SVT), □Wide or prolonged QRS is dangerous and might go to Vtach and die soon, for prevention give sodium bicarbonate subacute. □Atrial fibrillation/flutter □Wide complex tachycardia Cocaine Pharmacokinetics: Absorption □-Routes of administration □Insufflated (snorted) □IV (mainlined) □Inhaled (freebased) □Oral Pharmacokinetics: Distribution and Metabolism □-Both cocaine and amphetamines penetrate BBB easily □-Half-lives □ Cocaine: ~ 50-90 min □ Amphetamine: ~ 5-10 hours □ Meth: ~ 12 hours □-Metabolites include active and inactive compounds □-Cocaine is unusual in that it “autometabolizes” in the blood in addition to normal liver metabolism. □ Cocaine ----> norcocaine, ecgonine methyl ester, benzoylecgonine Cocaethylene □Alcohol inhibits metabolism Cocaethylene of cocaine (Alcohol makes it –Similar effects to cocaine –Greater cardiac toxicity than accumulate and last longer) cocaine □Alcohol + cocaine chemically –3-5x the half-life of cocaine react to form cocaethylene –associated with seizures, liver ACTIVE damage, compromised immune system □Only known example where body forms new psychoactive compound from two others Cocaine Pharmacodynamics □-Indirect Agonist for □DA=dopamine (high affinity). □NE= nore pinephrine(high affinity). □5-HT= seretonin(modest affinity). -Mechanism: Blocks monoamine reuptake. Hyperthermia fatal due to hot weather Amphetamine Pharmacodynamics □Indirect Agonist for □DA (high affinity) □NE (high affinity) □5-HT (low affinity) Unique feature in amphetamine. Mechanisms: –Blocks monoamine reuptake –Inhibit vesicular storage –Inhibit MAO metabolism Reverses reuptake Tutorial: https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bph.15465 Read this paper and explain how amphetamine abuse commonly leads to hyperthermia? Tolerance, Withdrawal, Addiction KHAT Catha edulis Ingestion large amount will cause sympathomimetic affect, seizures and cardiac arrhythmias. Addiction usually physologic.