💊 Typical Antipsychotics

Typical antipsychotics, also known as first-generation antipsychotics, are a class of medications primarily used to treat psychotic disorders. They are dopamine receptor antagonists, particularly at the D2 receptor.

These drugs exert their antipsychotic effect primarily by blocking dopamine D2 receptors in the mesolimbic pathway of the brain, reducing positive symptoms of psychosis. However, they also block D2 receptors in other pathways, leading to their characteristic side effects. Some also have anticholinergic, antihistaminic, and alpha-adrenergic blocking properties.

Typical antipsychotics are indicated for the treatment of acute and chronic schizophrenia, particularly for positive symptoms like hallucinations and delusions. They can also be used for severe agitation and aggression in various psychiatric conditions. Some are used for short-term management of severe anxiety and intractable hiccups.

Contraindications include Parkinson's disease due to exacerbation of motor symptoms, severe cardiovascular disease, and conditions predisposing to QT prolongation. They should be used with caution in patients with epilepsy, prostatic hypertrophy, and narrow-angle glaucoma due to anticholinergic effects. History of neuroleptic malignant syndrome is also a contraindication.

Common adverse effects include extrapyramidal side effects (EPS) such as akathisia, dystonia, and parkinsonism, and tardive dyskinesia with long-term use. Anticholinergic effects like dry mouth, constipation, and blurred vision are also common. Other side effects include sedation, orthostatic hypotension, and QT prolongation, which can lead to arrhythmias.

Regular monitoring for extrapyramidal side effects is crucial, especially during initiation and dose changes. ECG monitoring is recommended before and during treatment to assess for QT prolongation. Blood pressure should be monitored, particularly for orthostatic hypotension. Regular assessment for tardive dyskinesia is also important.

When prescribing, always check for known allergies to antipsychotics or related compounds. Be mindful of drug interactions, especially with other QT-prolonging medications or those affecting cytochrome P450 enzymes. Counselling should include explaining potential side effects like EPS, sedation, and the importance of adherence.

High-yield topics include the distinction between positive and negative symptoms of psychosis and how typical antipsychotics primarily address positive symptoms. Recognition and management of acute dystonia and akathisia are frequently tested. Understanding the risk of tardive dyskinesia with long-term use is key.

SBAs often focus on identifying extrapyramidal side effects and their management, such as differentiating acute dystonia from akathisia. Questions may also test knowledge of neuroleptic malignant syndrome presentation and initial steps. Understanding the link between D2 blockade and specific side effects is a common theme.