Drugs Used In Mental Illness Antipsychotic And Antimanic Drugs Question And Answers

Drugs Used In Mental Illness Antipsychotic And Antimanic Drugs

 

Question 1. Enumerate The Drugs Used In The Treatment Of Acute Psychosis. Describe The Mechanism Of Actions And Adverse Effects Of Typical Antipsychotics.
Answer:

Acute psychosis is a clinical syndrome that may be caused by a wide variety of disorders and is typically present in patients with rapid onset of psychotic symptoms, agitation, insomnia, and often hostility and combativeness.

Drugs Used In The Treatment Of Acute Psychosis

• Clozapine
• Risperidone
• Olanzapine
• Quetiapine
• Aripiprazole
• Ziprasidone.

Read And Learn More: Pharmacology Question And Answers

The following Drugs Are The Typical Antipsychotics

Typical Antipsychotics Phenothiazines

• Aliphatic side chain: Chlorpromazine, triflpromazine
  • Piperidine side chain: Thioridazine
  • Piperazine side chain: Trifloperazine, flphenazine
• Butyrophenones: Haloperidol, triflperidol, penflridol
• Thioxanthenes: Flupenthixol
• Other heterocyclics: Pimozide, loxapine.

Typical Antipsychotics Mechanism of Action

These drugs produce antipsychotic action by competitively blocking dopamine D2 receptors. Antipsychotic potency has shown a good correlation with their capacity to bind to D2 D3 and D4 receptors.

Blockades of dopaminergic projections to temporal and prefrontal areas constitute the limbic system and in mesocortical areas are probably responsible for antipsychotic action.

Typical Antipsychotics Adverse Effects

CNS Adverse Effects

Sedation, psychomotor impairment, and toxic confusional states at high doses. Sedation is more with phenothiazines, and thioxanthenes.

Other atypical agents are devoid of sedation, tolerance, and dependence. Tolerance develops to the sedative and autonomic side effects, but not to their antipsychotic action. Withdrawal effects are rare.

Neurological Adverse Effects

These are more common with classical neuroleptics:

• Dystonias (muscle rigidity)
• Akathisia (inability to sit still)
• Parkinsonism (extrapyramidal manifestations) due to D2 receptor blockade in the nigrostriatal pathway.
• Neuroleptic—malignant syndrome more common with fluphenazine or haloperidol
• Perioral tremors
• Tardive dyskinesia: These are involuntary orobuccal lingual dyskinesias, which result due to supersensitivity of newly formed D2 receptors in the striatal nerve cells.

Endocrinal Adverse Effects

These include hyperprolactinemia (gynecomastia in males, galactorrhea in females), weight gain, and pseudopregnancy.

Autonomic Adverse Effects

• Alpha-adrenergic blockade leads to postural hypotension, loss of libido, and delayed ejaculation. This is more common with chlorpromazine, thioridazine, and also from haloperidol.
• Antimuscarinic effects are usual anticholinergic side effects, but well tolerated and mild, more common with phenothiazines and thioridazine, and mild with haloperidol, and pimozide.

Question 2. Name Three Atypical Antipsychotic Agents.
Answer:

The following are three atypical antipsychotic agents:

• Clozapine
• Risperidone
• Olanzapine