PSYCHOPHARMACOLOGY

Terms

• Psychotropic medication:– Medications that affects psychic function,

behavior or experience• Neurotransmitter:– A chemical that is stored in the axon terminals of

the presynaptic neuron• Receptor:– Molecules situated on the cell membrane that are

binding sites for neurotransmitters

Effects of psychotropic medications on neurotransmitters

Medication Action on NT/ Receptor

Physiological effects Side effects

SSRI’s Inhibit reuptake of seretonin

Reduce depressionControl anxietyControl obsessions

Nausea, agitation, headache, sexual dysfunction

Tricyclic antidepressants

Inhibit reuptake of seretonoinInhibit reuptake of norepinephrine (NE)Block NE receptorBlock ACh receptorBlock histamine receptor

Reduce depressionRelief of severe painPrevent panic attacks

Sexual dysfunction(NE & 5 – HT)Sedation, weight gain (H1)Dry mouth, constipation, blurred vision, urinary retention (ACh), postural hypotension and tachycardia

Cont…Medication Action on NT/

ReceptorPhysiological effects

Side effects

MAO inhibitors Increase NE & 5 – HT by inhibiting the enzyme that degrades them (MAO – A)

Reduce depressionControl anxiety

Sedation, dizzinessSexual dysfunctionHypertensive crisis (interaction with tyramine)

Trazodone & nefazadone

5 – HT2 receptor antagonismAdrenergic receptor blockade

Reduce depressionReduce anxiety

Nausea, sedation, orthostasis, priapism

SSNRI’s: venlafaxine and duloxetine

Potent inhibitor of seretonin & norepinephrine reuptakeWeak inhibitor of dopamine reuptake

Reduce depressionRelieve pain of neuropathy (duloxetine)Relieve anxiety (venlafaxine)

Nausea, increased sweating, insomnia, tremors, sexual dysfunction

Bupropion Inhibits reuptake of 5-HT. NE & dopamine

Reduce depression, aid in smoking cessation, reduce symptoms of ADHD

Insomnia, dry mouth, tremor, seizures

Cont…Medication Action on NT/

ReceptorPhysiological effects Side effects

Antipsychotics: phenothiazines and haloperidol

Strong D, receptor blockadeWeaker blockade of ACh, H1, alpha adrenergic & 5-HT2 receptors

Relief of psychosisRelief of anxiety(Some) provide relief from nausea and vomitting and intractable hiccoughs

Blurred vision, dry mouth, decreased sweating, constipation, urinary retention. TachycardiaEPS, increased plasma prolactin (D2), sedation, weight gain (H1), ejaculatory difficulty (5-HT2), orthostatic hypotension

Antianxiety: benzodiazepines

Binds to BZ receptor sites on the GABA receptor complex, increases receptor affinity for GABA

Relief of anxietySedation

Dependency (with long term use)Confusion, memory impairment, motor incoordination

Cont…Medication Action on NT/

ReceptorPhysiological effects

Side effects

Antipsychotics (novel): clozapine, olanzapine, arip[iprazole, quetiapine, risperidone, ziprasidone

Receptor antagonism of 5-HTD1 – D5 (varies with drug)H1, alpha 1 adrenergic, muscarinic (ACh)

Relief of psychosis (with minimal or no EPS)Relief of anxietyRelief of acute mania

Potential with some of the drugs for mild EPS (D2)Sedation, weight gain (H1)Orthostasis & dizzinessBlurred vision, dry mouth, decreased sweating, constipation, urinary retention, tachycardia (ACh)

Antianxiety: buspirone

5-HT agonistD2 agonistD2 antagonist

Relief of anxiety Nausea, headache, dizzinessRestlessness

ANTIANXIETY AGENTS

• Indications– These are also called anxiolytics and minor

tranquilizers.– These are used in the treatment of anxiety

disorders, anxiety symptoms, acute alcohol withdrawal, skeletal muscle spasms, convulsive disorders, status epilepticus and preoperative sedation.

Cont…

• Side effects:– Drowsiness, confusion, lethargy– Tolerance; physical & psychological dependence– Ability to potentiate the effects of other CNS depressants– Possibility of aggravating symptoms in depressed persons– Orthostatic hypotension– Paradoxical excitement– Dry mouth– Nausea & vomiting– Blood dyscrasias– Delayed onset

Examples Chemical class Generic (trade) name

Antihistamines Hydroxyzine (Atarax, Vistaril)

Benzodiazepines Alprazolam (Xanax)Chlordiazepoxide (Librium)Clonazepam (Klonopin)Clorazepate (Traxene)Diazepam (Valium)Lorazepam (Ativan)Oxazepam (Serax)

Propanediols Meprobamate (Miltown)

Azaspirodecanediones Buspirone (BuSpar)

ANTIDEPRESSANTS

• Indications:– It is used in the treatment of dysthymic disorder,

major depression with melancholia or psychotic symptoms, depression associated with organic disease, alcoholism, schizophrenia or mental retardation, depressive phase of bipolar disorder and depression accompanied by anxiety.

– These drugs elevate mood and alleviate other symptoms associated with moderate-to-severe depression

Cont…

• Side effects with all chemical classes:– Dry mouth– Sedation– Nausea– Discontinuation syndrome– Hepatic failure

• Side effects with MAOI’s:– Hypertensive crisis

Cont…

• Side effects with tricyclics:– Blurred vision– Constipation– Urinary retention– Orthostatic hypotension– Reduction of seizure threshold– Tachycardia; arrhythmias– Photosensitivity– Weight gain

Cont…

• Side effects with SSRI’s:– Insomnia, agitation– Headache– Weight loss– Sexual dysfunction– Seretonin syndrome

Examples Chemical class Generic (trade) name

Tricyclics Amitriptyline, Amoxapine, Clomipramine, Desipramine, Doxepin, Imipramine, Nortriptyline, Protriptyline, Trimipramine

SSRI’s Citralopram, Fluoxetine, Fluvoxamine, Escitalopram, Paroxetine, Sertraline

MAOI Isocarboxazid, Phenelzine, Tranylcypromine

Others Bupropion, Maprotiline, Mirtazapine, Trazodone, Nefazodone, Venlafaxine, Duloxetine

MOOD STABILIZING AGENTSANTIMANIC:

Prevention and treatment of manic episodes of bipolar disorder, alcohol dependence, major depression

ANTICONVULSANTS:All stages of seizures

CALCIUM CHANNEL BLOCKERS:Angina, arrhytmias, hypertension, bipolar mania, migraine headache

ANTIPSYCHOTICS:Schizophrenia, bipolar mania

Cont…Chemical class Generic (trade) name

Antimanic Lithium carbonate

Anticonvulsants Clonazepam, carbamazepine, valporic acid, lamotrigine, gabapentin, topiramate

Calcium channel blocker Verapamil

Antipsychotics Olanzapine, aripiprazole, chlorpromazine, quetiapine, risperidone, ziprasidone

Cont…• Side effects of antimanic:

– Drowsiness, dizziness, headache– Dry mouth, thirst– GI upset, nausea/ vomiting– Fine hand tremors– Hypotension, arrhythmias, pulse irregularities– Polyuria, dehydration– Weight gain

• Side effects of calcium channel blockers:– drowsiness, dizziness– Hypotension, bradycardia– Nausea– constipation

Cont…• Side effects of anticonvulsants:

– Nausea/ vomitting– Drowsiness, dizziness– Blood dyscrasias– Prolonged bleeding time– Risk of severe rash– Decreased efficacy with oral contraceptives

• Side effects of antipsychotics:– Drowsiness, dizziness– Dry mouth, constipation– Increased appetite, weight gain– ECG changes– Extra Pyramidal Symptoms– Hyperglycemia & diabetes

ANTIPSYCHOTIC AGENTS• Indications:– These are also called major tranquilizers and

neuroleptics.

– They are used in the treatment of acute and chronic psychoses particularly when accompanied by increased psychomotor activity

– Selected agents are used as antiemetics in the treatment of intractable hiccoughs and for the control of tics and vocal utterances in Tourette’s disorder

Examples Chemical class Generic (trade) name

Phenothiazines Chlorpromazine, Fluphenazine, Perphenazine, Prochlorperazine, Thioridazine, Trifluoperazine

Thioxanthene Thiothixene

Benzisoxazole Risperidone

Dibenzoxazepine Loxapine

Dihydroindolone Molindone

Dibenzodiazepine Clozapine

Diphenylbutylpiperidine Pimozide

Thienobenzodiazepine Olanzapine

Dibenzothiazepine Quetiapine

Benzothiazolylpiperazine Ziprasidone

Dihydrocarbostyril Aripiprazole

Cont…• Side effects of antipsychotics:

– Anticholinergic effects such as dry mouth, blurred vision, constipation, urinary retention

– Nausea, GI upset– Skin rash– Sedation– Orthostatic hypotension– Photosensitivity– Hormonal effects– ECG Changes– Reduction of seizure threshold– Agranulocytosis– Hypsersalivation

Cont…

• Extrapyramidal symptoms (EPS)– Pseudoparkinsonism– Akinesia– Akathisia– Dystonia– Oculogyric crisisTardive dyskinesiaNeuroleptic malignant syndromeHyperglycemia and diabetes

SEDATIVE HYPNOTICS

• Indications:– They are used in the short term management of

various anxiety states and to treat insomnia.

– Selected agents are used as anticonvulsants and preoperative sedatives and to reduce anxiety associated with drug withdrawal

Examples Chemical class Generic (trade) name

Barbiturates Amobarbital, Butabarbital, Mephobarbital, Pentobarbital, Phenobarbital, Secobarbital

Benzodiazipines Estazolam, Flurazepam, Quazepam, Temazepam, Triazolam

Miscellaneous Chloral hydrate, Eszopiclone, Zaleplon, Zolpidem

Cont…

• Side effects:– Drowsiness, confusion, lethargy– Tolerance; physical & psychological dependence– Ability to potentiate the effects of other CNS depressants– Possibility of aggravating symptoms in depressed persons– Orthostatic hypotension– Paradoxical excitement– Dry mouth– Nausea & vomiting– Blood dyscrasias– Delayed onset

Newer trends – agents for ADHD

• Indications:– These are used for ADHD in children and adults

• Side effects:– Overstimulation, restlessness, insomnia– Palpitations, tachycardia– Anorexia, weight loss– Tolerance, physical and psychological dependence– Nausea and vomiting– Constipation– Potential for seizures

Examples Chemical class Generic (trade) name

Amphetamines Dextroamphetamine sulfate, Methamphetamine

Amphetamine mixtures Dextroamphetamine/ amphetamine

Miscellaneous Methylphenidate, Dexmethylphenidate, Pemoline, Atomoxetine, Bupropion