Antipsychotic Agents& Lithium (Pharmacology)

Antipsychotics

Bipolar drugs

2.Thioxanthene

3.Butyrophenone

1.Phenothiazines

4.Atypicals

Effects

Clinical uses

Mechanism of Action

Pharmacokinetics

Drugs

Toxicities

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Chlorpromazine

Fluphenazine

Thioridazine

Block of D2,receptors >>5-HT2 receptors

Block α, M, and H1 receptors

Schizophrenia, Bipolar disorder(Manic phase)

Oral and parenteral forms, hepatic metabolism , long half-life

Extensions of α- and M receptor-blocking actions ,Extrapyramidal dysfunction, tardive dyskinesias,
hyperprolactinemia

Drug

Thiothixene

Effects

Clinical uses

Mechanism of Action

Pharmacokinetics

Drug

Toxicities

Haloperidol

Block of D2 receptors >>5-HT2 receptors

Some α block

Schizophrenia ; bipolar disorder (manic phase), Huntington’s chorea, Tourette’s syndrome

Oral and parenteral form, Hepatic Metabolism

Extrapyramidal dysfunction(major)

Mechanism of Action

Effects

Clinical uses*

Pharmacokinetics

Drugs

Toxicities

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Aripiprazole

Clozapine

Olanzapine

Quetiapine

Risperidone

Ziprasidone

Block of 5-HT2 Block of 5-HT2
receptors >> D2
receptors

Some α block (clozapine, risperidone, ziprasidone) and M block (clozapine, olanzapine), variable H1 block

Schizophrenia (positive and negative): Bipolar disorder,Major Depressive,agitation in Alzheimer’s and Parkinson’s.

Oral and parenteral form, Hepatic Metabolism

Agranulocytosis s (clozapine);DM,Weight gain (clozapine, olanzapine), hyperprolactinemia (Risperidone),QT Prolong (ziprasidone)

1.Lithium

2.Alternative drugs for bipolar affective disorder

Clinical uses

Pharmacokinetics

Effects

Toxicities

Mechanism of Action

Uncertain, suppresses IP3 and DAG signaling

No specific actions on ANS receptors or specific CNS Receptors:No sedation

Bipolar affective disorder: Prevenrt Mood swings (Prophylaxis)

Renal elimination half life 20 hr : Narrow Therapeutic window Monitor Blood levels

Tremor, edema, hypothyroidism, renal dysfunction Pregnancy Category D

Effects

Mechanism of Action

Clinical uses

Pharmacokinetics

Drugs

Toxicities

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Carbamazepine

Lamotrigine

Valproic acid

Unclear actions in bipolar disorder

Ataxia and diplopia(carbamazepine),Nausea,Dizeness,and headache (Lamotrigine)Gastrointestinal Distress, Weight Grain,Alopesia(Valproic acid)

Valproic acid competes with lithium as
first choice in bipolar disorder, acute phase

Carbamazepine forms active metabolite (phase I); lamotrigine and valproic acid form conjugates (phase II)

Hematotoxicity and
induction of drug metabolism,Rash, Hepatic dysfunction,Weight gain,Inhibition drug metabolism