CNS Stimulants

1. Analeptics2. Anorexiants

3. Antidepressants4. Serotonin agonists

CNS Stimulants: Adverse effects

• CVS: Palpitation, tachycardia, hypertension, angina, dyshythmia

• CNS: Nervousness, restlessness, anxiety

• Endocrine: Hypoglycemia, hyperglycemia

• GIT: Nausea, vomiting,diarrhea

Analeptic

• Used to stimulate respiration when natural reflex is lost

• H-cholinomimetic (reflex analeptic)

• Central analeptic (Aminophyllin, theophylline,Caffeine, Doxapram)

Did You Know?

• Caffeine is a xanthine alkaloid compound that acts as a stimulant in humans. Caffeine is sometimes called guaranine when found in guarana, mateine when found in mate, and theine when found in tea. It is found in the leaves and beans of the coffee plant, in tea, yerba mate, and guarana berries, and in small quantities in cocoa, the kola nut and the Yaupon Holly. Overall, caffeine is found in the beans, leaves, and fruit of over 60 plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding upon them.

Chemical Properties

Molar Mass = 194.19 g mol−1 Density: 1.2 g/cm³

Phase: Solid

Melting Point: 237 °C

Boiling Point: 178 °C

Uses of Caffeine

• Caffeine is a central nervous system (CNS) stimulant, having the effect of temporarily warding off drowsiness and restoring alertness. Beverages containing caffeine, such as coffee, tea, soft drinks and energy drinks enjoy great popularity: caffeine is the world's most widely consumed psychoactive substance. In North America, 90% of adults consume caffeine daily.

Metabolizing Of Caffeine• Caffeine is completely absorbed by the stomach and

small intestine within 45 minutes of ingestion. After ingestion it is distributed throughout all tissues of the body and is eliminated by first-order kinetics. The half-life of caffeine varies widely among individuals according to such factors as age, liver function, pregnancy, some concurrent medications, and the level of enzymes in the liver needed for caffeine metabolism. In healthy adults, caffeine's half-life is approximately 3-4 hours. In women taking oral contraceptives this is increased to 5-10 hours, and in pregnant women the half-life is roughly 9-11 hours. Caffeine can accumulate in individuals with severe liver disease when its half-life can increase to 96 hours.

Caffeine

• AP

• Hate rate

• Respiratory stimulation

• Adjunctive effect

Doxapram

• over dosage of CNS depressant

• COPD (chronic obstructive pulmonary disease

• Respiratory depression in postoperative recovery period

Doxapram: Contraindication

• Newborn

• Epilepsy

• Hypertension

• Stroke

Amphetamines

• Produce mood elevation or euphoria, increase mental alertness and capacity for work, decrease fatigue and drowsiness, prolong wakefulness.

Amphetamines usage

• Narcolepsy

• ADHD (attention-deficit/hyperactivity disorder

Amphetamines

• Tolerance

• Psychological dependence

• High abuse potential (under Control Substance Act

Methylxanthines

• COPD (chronic obstructive pulmonary disease

• Respiratory depression in postoperative recovery period

Anorexants

• Central acting (Benzphetamine, diethylpropion, Sibutramine)

• Metabolism acting (orlistat)

Antidepressants

• Used to treat depression• Depression, common feelings

– Pessimism– Worry– Intense sadness– Loss of concentration– Slowing of mental processes – Problems with eating and sleeping

Serotonin agonist (Sumatriptan)

• Treatment of migraine

Antidepressants Common Symptoms of Depression

– Loss of interest in usual activities

– Low self-esteem– Self-pity– Significant weight loss

or gain– Insomnia or

hypersomnia– Extreme restlessness

– Loss of energy– Feelings of

worthlessness– Diminished ability to

think– Feelings of guilt– Recurrent thoughts of

death– Suicide attempts

Antidepressants

Depression

• Women are affected more often than men

• When men are affected, it is usually later in life

• Levels of neurotransmitters in the brain may be a causative factor

Mood Disorders

• Mania

• Bipolar Disorder

• Unipolar Disorder

Mood Disorders

• ManiaMood of extreme excitement, excessive elation, hyperactivity, agitation, and increased psychomotor activity

• Bipolar Disorder

• Unipolar Disorder

Mood Disorders

• Mania

• Bipolar DisorderMood swings alternate between major depression and mania

• Unipolar Disorder

Mood Disorders

• Mania

• Bipolar Disorder

• Unipolar DisorderMajor depression with no previous occurrence of mania

Treatment for Depression

Electroconvulsive Therapy• Introduction of brief, but convulsive

electrical stimulation through the brain

• Can induce seizures

• Effective for major and delusional depression

Antidepressants

• Selective Serotonin Reuptake Inhibitors (SSRIs)

• Cyclic Antidepressants

• Monoamine Oxidase Inhibitors (MAOIs)

Antidepressants

Selective Serotonin Reuptake Inhibitors (SSRIs)

– Block the reuptake of serotonin, with little effect on norepinephrine

– Fewer side effects than older meds

Treatments

Cyclic Antidepressants – Two Types

• Tricyclic antidepressants (TCAs)• Tetracyclic antidepressants

– Prevent reuptake of norepinephrine and/or serotonin

– Agents in this class differ in adverse effects, cost, and response

Treatments

Monoamine Oxidase Inhibitors (MAOIs)Allows for buildup of norepinephrine at the synapse

SSRIs for Depression• citalopram (Celexa)

• escitalopram (Lexapro)

• fluoxetine (Prozac, Sarafem)

• fluvoxamine

• paroxetine (Paxil)

• sertraline (Zoloft)

• venlafaxine (Effexor)

Drug List

Dispensing Issues

Look-Alike Drugs

– Prozac and Proscar (urinary drug)

– Zoloft and Zocor (high cholesterol)

– Celexa and Cerebyx (seizures) and Celebrex (arthritis)

Warning!

SSRIDispensing Issues

• Do not discontinue abruptly

• Alcohol consumption should be avoided while taking these medications

Warning!

fluoxetine (Prozac)

• Indicated for major depression and obsessive-compulsive disorder (OCD)

• Anorexia is a possible adverse effect

• Take in the morning to avoid insomnia

paroxetine (Paxil)

• Indicated for depression, obsessive-compulsive disorder, and panic disorder

venlafaxine (Effexor)

• Blocks reuptake of serotonin and norepinephrine

• Indicated for depression

• May cause increase in blood pressure and blurred vision

sertraline (Zoloft)

• Indicated for depression and obsessive-compulsive disorder

• Primary side effect is nausea

• May also cause drowsiness

citalopram (Celexa)

• Indicated for depression and obsessive-compulsive disorder

• Minimal drug interactions

escitalopram (Lexapro)

• Similar to Celexa

• More potent with fewer side effects

Cyclic Antidepressants

Tricyclic• amitriptyline (Elavil)• clomipramine (Anafranil)• desipramine (Norpramin)• doxepin (Sinequan)• imipramine (Tofranil)

Drug List

Cyclic Antidepressants

Tricyclic

• nortriptyline (Aventyl, Pamelor)

• protriptyline (Vivactil)

• trimipramine (Surmontil)

Tetracyclic

• maprotiline

Drug List

Tricyclic Antidepressants Dispensing Issues

• Improvements are usually seen in 10 to 21 days

• Can be cardiotoxic in high doses

• May cause postural hypotension

Warning!

Tricyclic AntidepressantsDispensing Issues

Do not discontinue abruptly.Warning!

Cyclic Antidepressants Side Effects

• Sedation is common, but tolerance usually occurs

• Have many anticholinergic effects

Discussion

Why would cyclic antidepressants be prescribed for bed wetting in children?

Discussion

Why would TCAs be prescribed for bed wetting in children?

Answer They may be prescribed because of their anticholinergic side effects.

MAOIs

• phenelzine (Nardil)

• selegiline (Eldepryl)

• tranylcypromine (Parnate)

Drug List

MAOI Dispensing Issues

Be cautious of many interactions with foods such as aged cheeses, concentrated yeast extracts, pickled fish, sauerkraut, broad bean pods, chocolate, and alcohol.

Warning!

MAOI Dispensing Issues

If changing to another class of antidepressant, patient must have a two-week “wash out” period before starting the new medication.

Warning!

Other Antidepressants

• bupropion (Wellbutrin, Zyban)

• mirtazapine (Remeron)

• trazodone (Desyrel)

Drug List

trazodone (Desyrel)

• Prevents reuptake of serotonin and norepinephrine

• Has a better side effect profile than TCAs

• Caution: possible interaction with Ginkgo

bupropion (Wellbutrin, Zyban)

• Dopamine-uptake inhibitor

• Does not cause sedation, blood pressure changes, or ECG changes

• Do not discontinue abruptly

• Approved in the aid of smoking cessation

Other Antidepressant Dispensing Issues

• Wellbutrin SR = BID dosing

• Wellbutrin XL = QD dosing

Warning!

Bipolar Disorders

Signs or Symptoms– Decreased need for sleep– Elevated or irritable mood– Excessive involvement in pleasurable

activities with a big potential for painful consequences

– Grandiose ideas– Pressure to keep talking– Racing thoughts

Discussion

What is the drug of choice for treating bipolar disorders?

Discussion

What is the drug of choice for treating bipolar disorders?

Answer

Lithium

Discussion

What is the two-fold objective of drug therapy for bipolar disorder?

Discussion

What is the two-fold objective of drug therapy for bipolar disorder?

Answer

Treat acute episodes

Prevent subsequent attacks

Drugs to Treat Bipolar Disorders

• carbamazepine (Epitol, Tegretol)

• divalproex (Depakote)

• lithium (Eskalith, Lithobid)

• olanzapine-fluoxetine (Symbyax)

• valproic acid (Depakene)

Drug List