Antipsychotics

Antipsychotics

​Dr Elsa Haniffah Mejia Mohamed

What was covered:

•Brief review on the dopamine hypothesis of schizophrenia.

•Review on the major dopamine pathways and the pharmacological effects resulting from the blockade of the dopamine receptors at these pathways.

•Classification of antipsychotic agents

•Comparison between the typical and atypical antipsychotics based on their pharmacological actions, therapeutic uses and adverse effects

•Drugs used in bipolar disorders, with focus on lithium

Some text here about the topic of discussion

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Blockade of dopamine levels at the mesolimbic pathway relieves

symptoms

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Increase in dopamine levels in the mesocortical pathway relieves

symptoms

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Blockade of Dopamine receptors at the

pathway produces extrapyramidal side effects (EPS)

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Blockade of Dopamine receptors at the tuberoinfundibular pathway causes

Amisulpride

Second gen, antagonist at D2/D3

Selective effect to mesolimbic and less on nigrostrial pathway

Dual action:

-high dose: blocks post-synaptic D2 receptors at mesolimbic region

-low dose: ​blocks pre-synaptic D2 receptors at mesocortical region

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Amisulpride improves negative symptoms at ___doses, positive symptoms at ___doses

Open Ended

Why does amisulpride produces less EPS?

Open Ended

What is the mechanism that leads to tardive dyskinesia with prolonged treatment with antipsychotics?

Multiple Choice

Select correct responses regarding slow-release antipsychotic formulations:

• Hydroxylase breaks down the suspension so the drug is slowly released into the circulation

• Use can improve compliance

• Use is preferred in patients who suffered severe EPS with typical drugs

• Only typical (or first generation APs) drug preparations are available

Multiple Select

Lithium is used mainly for prophylactic treatment of bipolar disorder

• True

• False

Multiple Choice

Why does lithium cause hypothyroidism?

• interferes with iodine uptake

• inhibits thyroxine production

• inhibits conversion of T4 to T3

• All of the above

Multiple Choice

Thiazide diuretics cause a ____in lithium levels because thiazide

• decrease, increases excretion of lithium

• decrease, inreased metabolism of lithium

• increase, reduces excretion of lithium

• increase, decreased metabolism of lithium

Thiazide decreases Na+ excretion at the distal tubule -->creates Na+ deficit

--> increase resorption of Na+ and Li+ at the PCT

Lithium and thiazide interactions

Multiple Select

Which one of these corresponds to renal adverse effects due to treatment with lithium?

• Diabetes insipidus

• Minimal change glomerulonephritis

• interstitial nephritis

• All of the above

Renal adverse effects of lithium

• Diabetis insipidus: Chronic lithium ingestion can lead to resistance to ADH, resulting in polyuria and polydipsia. Lithium enters the principal cells of the collecting duct, then accumulates in these cells and interferes with the ability of ADH to increase water permeability

• Other nephrotoxic effects of lithium are not well understood

Antipsychotics self study

https://edpuzzle.com/open/zogtamb