Nortriptyline (Nortriptyline Hydrochloride)

Nortriptyline is a tricyclic antidepressant indicated for several psychiatric and pain conditions.

• Major depressive disorder: alleviates depressive symptoms in adult patients.
• Depressive episodes in bipolar disorder: helps manage depressive phases of bipolar I or II.
• Chronic neuropathic pain: reduces pain associated with peripheral neuropathy.

• Nortriptyline inhibits the reuptake of norepinephrine and serotonin, increasing their synaptic concentrations. It also antagonizes muscarinic cholinergic, histamine H1, and α1‑adrenergic receptors, contributing to its therapeutic and side‑effect profile. These actions modulate neuronal signaling in limbic and pain pathways, enhancing mood and diminishing pain perception. The drug’s lipophilic nature allows it to cross the blood‑brain barrier efficiently.

Nortriptyline may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Dry mouth: reduced salivation leading to discomfort.
• Constipation: slowed gastrointestinal motility.
• Drowsiness: sedation or fatigue.
• Weight gain: increased appetite or metabolic changes.
• Blurred vision: temporary visual disturbances.
• Orthostatic hypotension: dizziness upon standing.

Serious or Rare Side Effects

• Cardiac arrhythmias: irregular heart rhythm, especially in overdose.
• Seizures: risk of convulsions, particularly at high doses.
• Severe hypotension: marked drop in blood pressure.
• Hepatotoxicity: liver enzyme elevations or injury.
• Serotonin syndrome: potentially life‑threatening condition when combined with serotonergic agents.
• Allergic reactions: rash, angioedema, or anaphylaxis.

Before prescribing nortriptyline, clinicians should consider several safety precautions.

• Cardiac assessment: evaluate history of heart disease and obtain baseline ECG.
• Concomitant CNS depressants: avoid or monitor use with alcohol, benzodiazepines, or opioids.
• Seizure risk: assess for epilepsy or conditions lowering seizure threshold.
• Elderly patients: start with lower doses and monitor for anticholinergic effects.
• Pregnancy and lactation: use only if potential benefit outweighs risk; consult obstetric guidance.
• Store at ambient temperature: keep below 25°C in original packaging, protect from moisture.

Nortriptyline can interact with various medicines, altering its effectiveness or safety.

Major Interactions (Avoid)

• MAO inhibitors: risk of severe hypertensive crisis or serotonin syndrome.
• SSRIs or SNRIs: increased serotonin levels may precipitate serotonin syndrome.
• Anticholinergic drugs: additive anticholinergic burden leading to severe side effects.

Moderate Interactions (Monitor Closely)

• CYP2D6 inhibitors (e.g., fluoxetine, quinidine): may raise nortriptyline plasma levels.
• CYP2D6 inducers (e.g., rifampin): may reduce drug concentrations.
• Diuretics: may enhance orthostatic hypotension.
• Anticoagulants (e.g., warfarin): monitor INR for possible changes.