Ketipinor (Quetiapine)

Quetiapine acts on multiple neurotransmitter pathways to manage serious psychiatric conditions.

• Schizophrenia: reduces psychotic symptoms such as delusions and hallucinations.
• Bipolar disorder (manic episodes): stabilises mood and diminishes manic energy and agitation.
• Bipolar disorder (depressive episodes): alleviates depressive symptoms and improves mood.
• Adjunct treatment of major depressive disorder: enhances the therapeutic response when used with antidepressants.

• Quetiapine exerts its effect by antagonising serotonin 5‑HT2A, dopamine D2, histamine H1, and adrenergic α1 receptors, among others. This receptor profile modulates neurotransmission, decreasing dopaminergic activity linked to psychosis while balancing serotonergic pathways that influence mood and cognition. The combined antagonism leads to symptom control in schizophrenia, bipolar disorder and adjunctive depression therapy.

Quetiapine may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Sedation or drowsiness
• Dizziness or light‑headedness
• Dry mouth
• Constipation
• Weight gain
• Orthostatic hypotension

Serious or Rare Side Effects

• Agranulocytosis (dangerously low white‑blood‑cell count)
• Neuroleptic malignant syndrome (life‑threatening reaction)
• Tardive dyskinesia (involuntary movements)
• Severe hypotension or syncope
• Suicidal thoughts or behaviours
• Myocarditis or cardiomyopathy

When prescribing or dispensing quetiapine, several safety considerations are essential.

• Monitor metabolic parameters: regularly assess weight, fasting glucose and lipid profile.
• Assess for suicidal ideation: especially during early treatment phases.
• Evaluate cardiovascular status: watch for orthostatic hypotension and arrhythmias.
• Use caution in hepatic impairment: dose adjustments may be required.
• Avoid abrupt discontinuation: taper under medical supervision to prevent withdrawal.
• Store at room temperature: keep in the original container, protect from moisture and light.

Quetiapine interacts with several drug classes that may alter its efficacy or safety.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): increase quetiapine plasma levels.
• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): reduce quetiapine exposure.
• Central nervous system depressants (alcohol, benzodiazepines): enhance sedation and respiratory depression.
• Antihypertensive agents: additive orthostatic hypotension.
• QT‑prolonging drugs (e.g., sotalol, erythromycin): raise risk of cardiac arrhythmias.

Moderate Interactions (Monitor Closely):\n- Anticholinergic medications: may worsen dry mouth and constipation.

• Other antipsychotics or dopamine‑modulating agents: increase risk of extrapyramidal symptoms.
• Serotonergic agents (e.g., SSRIs, SNRIs): potential for serotonin syndrome, especially at high doses.