Ketipine (Quetiapine)

Ketipine (quetiapine) is used within the antipsychotic therapeutic class to manage several psychiatric conditions.

• Schizophrenia: reduces psychotic symptoms such as hallucinations and delusions.
• Bipolar disorder (manic and depressive episodes): stabilises mood and prevents relapse.
• Adjunct treatment of major depressive disorder: enhances antidepressant response when added to standard therapy.

• Quetiapine acts as an antagonist at serotonin 5‑HT2A, dopamine D2, histamine H1, and adrenergic α1 receptors. By blocking these receptors, it modulates neurotransmission, decreasing dopaminergic activity linked to psychosis while influencing serotonergic pathways that affect mood and cognition. The combined receptor profile contributes to its antipsychotic and mood‑stabilising effects.

Quetiapine may cause a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Drowsiness: feeling unusually sleepy or fatigued.
• Dry mouth: reduced salivation leading to discomfort.
• Constipation: infrequent or difficult bowel movements.
• Weight gain: increase in body weight over time.
• Dizziness: sensation of light‑headedness or unsteadiness.
• Orthostatic hypotension: drop in blood pressure upon standing.

Serious or Rare Side Effects

• Neuroleptic malignant syndrome: rare but life‑threatening reaction with fever and muscle rigidity.
• Tardive dyskinesia: involuntary, repetitive movements, often of the face.
• Suicidal thoughts: emergence or worsening of suicidal ideation.
• Severe allergic reactions: rash, swelling, or difficulty breathing.
• Elevated blood glucose: hyperglycaemia or new‑onset diabetes.
• Cardiac arrhythmias: abnormal heart rhythms, especially in patients with pre‑existing heart disease.

Before initiating Ketipine, clinicians should assess patient history and monitor for specific risks.

• Cardiovascular assessment: evaluate for orthostatic hypotension and heart disease.
• Metabolic monitoring: check blood glucose, lipids, and weight regularly.
• CNS depression: avoid concurrent sedatives that may enhance drowsiness.
• Pregnancy and lactation: discuss potential risks with the prescriber; data are limited.
• Elderly patients: start at lower doses and monitor for falls or confusion.
• Store at ambient temperature: keep below 25 °C, retain in original packaging, protect from moisture and direct sunlight.

Quetiapine can interact with several drug classes, requiring careful management.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may increase quetiapine plasma levels and toxicity.
• CNS depressants (e.g., benzodiazepines, opioids): can cause excessive sedation or respiratory depression.

Moderate Interactions (Monitor Closely):\n- CYP3A4 inducers (e.g., rifampicin, carbamazepine): may reduce efficacy by lowering drug concentrations.

• Antihypertensives: additive effect on blood pressure lowering, watch for orthostatic symptoms.
• Anticholinergic agents: may worsen dry mouth and constipation.
• Lithium: combined use may increase risk of neurotoxicity.
• Alcohol: can potentiate sedation and impair cognition.