CNS STIMULANTS

l PSYCHOMOTOR STIMULANTS l CAUSE EXCITEMENT & EUPHORIA l INCREASE MOTOR ACTIVITY l PSYCHOTOMIMETIC DRUGS l PROFOUND CHANGES IN THOUGHT PATTERNS AND MOOD l FEW DRUGS USED CLINICALLY l IMPORTANT AS DRUGS OF ABUSE

CNS STIMULANTS CNS STIMULANTS PSYCHOMOTOR STIMULANTS l AMPHETAMINE l CAFFEINE l COCAINE l NICOTINE l METHYLPHENI DATE l METHYLXANTH INES PSYCHOTOMIMETIC DRUGS l LYSERGIC ACID DIETHYLAMIDE (LSD) l PHENCYCLIDINE l TETRAHYDROCANN ABINOL

METHYLXANTHINES METHYLXANTHINES l Caffeine – found in coffee, tea, colas l Theophylline – found in tea l Theobromine – found in chocolate

METHYLXANTHINES METHYLXANTHINES l THEOBROMINE,THEOPHYLLINE l MECH: TRANSLOCATION OF EXTRACELLULAR CALCIUM, ↑ IN cAMP, cGMP, by inhibiting Phosphodiesterase enzyme

USES l Relaxation of smooth muscle of bronchioles. l Used to treat Asthma SE: l Insomnia, anxiety, agitation

l General Positive Effects l increased mental alertness, wakefulness l increased energy, sense of well-being l Decrease fatigue l have potential for toxicities l have potential for physical dependence

l CNS: ↓ fatigue, ↑mental alertness l CVS: + inotropic & + chronotropic l ↑ diuretic action l ↑ secretion of Hcl in gastric mucosa

l increased respiratory drive& rate l increased urine output (is a diuretic) l increased HR, cardiac force, BP, dilation of coronary arteries l decreased smooth muscle activity (is a vasodilator in peripheral blood vessels, but a vasoconstrictor of CNS blood vessels; l Opens bronchi, bronchodilator l increased basal metabolic rate

l Mechanisms of Action of Caffeine l caffeine blocks adenosine receptors

l many headache OTC drugs have caffeine in them l for vascular (migraine) headaches l for diuretic l for mild assist to memory, concentration, learning l for ADHD, for narcolepsy (a “poor man’s speed”) l for weight loss l as a respiratory stimulant (e.g. asthma, central sleep apnea) Therapeutic Uses of Caffeine

l daily use of caffeine can induce significant degree of tolerance and physical dependence l caffeine withdrawl Sxs: moderate to severe headache l drowsiness, fatigue, less alert, less active, lethargy l Anxiety or depression l flu-like Sxs (malaise, muscle aches, abdominal cramps, etc.) l nausea, vomiting l irritability

l lethal dose = 10 grams caffeine/day (= 100 cups coffee) l “caffeinism” – a clinical pattern seen with caffeine OD l anxiety, agitation, severe insomnia, irritability, l tachycardia, High BP, cardiac arrhythmias, l severe GI disturbances, cramping, and acid reflux, l tinnitus, delerium

NICOTINE NICOTINE l Mech: ganglionic stimulation by depolarization ( Low doses) l CNS: euphoria, arousal, attention l ↑ in B.P & H.R. l ↑ in GI motility l Each cigarette contains 6-8mg.

l High doses causes ganglionic blockade l High doses cause resp. paralysis & Severe hypotension.

Withdrawal symptoms l Addictive, physical dependence l Insomnia, anxiety, restlessness l Headaches, difficulty in concentration

COCAINE COCAINE l Highly addictive, drug abuse l Blockade of neurotransmitter reuptake l This ↑ CNS & peripheral actions of catecholamines.. l Intense euphoria is due to ↑ Dopaminergic effects.

Actions: l Powerful stimulation of cortex & brainstem, which causes hallucinations, delusions, euphoria l Peripherally causes – tachycardia, hypertension, mydriasis, peripheral vasoconstriction.

USES: l As local anesthetic which causes vasoconstriction l Rarely used l Mech of action – Na Channel Blocker

SE: l Anxiety, hypertension, tachycardia, l Hyperthermia due to impaired sweating l Seizures and fatal cardiac arrhythmias, resp. failure.

Amphetamine l Mech: increased release of intracellular stores of catecholamines. l Psychological and physiological dependence Actions: l CNS: increased alertness, decreased fatigue, insomnia. l Norepinephrine release ↑

l Amphetamine is a powerful central nervous system stimulant drug, used recreationally for the euphoriant effects, l "functionally" to ward off fatigue and increase energy and capacity for physical activity.

l amphetamine used in the treatment of the sleeping disorder narcolepsy and l the behavioral syndrome called called attention deficit hyperactivity disorder (ADHD). l Used to reduce appetite

SE: l Insomnia, dizziness, tremor, irritability, cardiac arrhythmias, hypertension, anorexia, abdominal cramps…

Methylphenidate l Has central stimulant actions same as amphetamine.. Used mainly for l Narcolepsy l Also for Attention deficit syndrome.

LYSERGIC ACID DIETHYLAMIDE (LSD) l Multiple sites in CNS l Serotonin agonist l Hallucinogen l Increased B.P, body temp.. l Dependence l SE: hyperreflexia, muscular weakness l High doses Psychotic symptoms l Rx with Haloperidol

l The physical effects include dilated pupils, higher body temperature, increased heart rate and blood pressure, sweating, loss of appetite, sleeplessness, dry mouth, and tremors.

l Users refer to their experience with LSD as a "trip" and to acute adverse reactions as a "bad trip." experience severe, terrifying thoughts and feelings, l fear of losing control, fear of insanity and death, and despair while using LSD. l LSD users experience flashbacks

l LSD is not considered an addictive drug l Haloperidol & other Antipsychotic drugs can be used to block the hallucinatory actions of LSD.

Tetrahydrocannabinol l Marijuana (cannabis) l Euphoria, drowsiness, relaxation l Impairs memory and mental activity. l Xerostomia, hallucinations, delusions.. l Dependence l Tetra hydro cannabinol is an appetite stimulant and antiemetic. l dronabinol (a synthetic version of THC)

Indications for Use Indications for Use l The research evidence most strongly supports the use of Dronabinol in the following areas: l Nausea and vomiting, especially when due to chemotherapy for cancer or HIV-AIDS l Anorexia, especially in the setting of HIV- AIDS l Chronic pain, especially when due to damaged nerves (e.g., spinal cord injury) l Muscle spasms and spasticity (e.g., multiple sclerosis, post-stroke syndrome)

PHENCYCLIDINE (ANGEL DUST) l Blocks re uptake of dopamine, NE, 5-HT… l Major action is to block the ion channel regulated by NMDA subtype of Glutamate receptor l Causes Dissociative anesthesia & analgesia l It's pharmacological nature is commonly referred to as Dissociative Anesthetic, l however it can possess the properties of a CNS depressant, a hallucinogenic, and an analgesic.

l Hostile and bizarre behavior. l Staggered gait, muscular rigidity. l High dose -- coma