Nortriptyline

Nortriptyline is a tricyclic antidepressant that modulates neurotransmitter activity and is employed in the management of several mood and pain disorders.

• Major depressive disorder: alleviates depressive symptoms, improves mood, sleep, and appetite in adult patients.
• Neuropathic pain: reduces pain intensity and abnormal sensations associated with peripheral nerve damage, such as diabetic neuropathy.
• Chronic tension-type headache: decreases frequency, duration, and severity of tension‑type headache episodes in individuals with recurrent headaches.

• Nortriptyline inhibits the reuptake of norepinephrine and serotonin, increasing their synaptic concentrations. It also antagonizes muscarinic acetylcholine, histamine H1, and alpha‑adrenergic receptors, contributing to its analgesic and sedative properties. The blockade of these receptors also leads to anticholinergic effects and can influence cardiovascular tone, which are relevant to its safety profile.

Nortriptyline may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Dry mouth: reduced salivation leading to discomfort.
• Constipation: slowed gastrointestinal transit.
• Drowsiness: increased sedation, especially at treatment initiation.
• Weight gain: gradual increase in body weight.
• Blurred vision: temporary visual disturbances.
• Orthostatic hypotension: dizziness upon standing.

Serious or Rare Side Effects

• Cardiac arrhythmias: irregular heart rhythm that may be life‑threatening.
• Seizures: heightened risk of convulsive episodes.
• Severe hypotension: marked drop in blood pressure causing fainting.
• Hepatotoxicity: liver enzyme elevation or injury.
• Neuroleptic malignant syndrome‑like reactions: high fever, muscle rigidity.
• Suicide ideation: worsening depression or emergence of suicidal thoughts.

When prescribing nortriptyline, clinicians should consider several precautions to minimize risks and ensure safe use.

• Cardiac assessment: evaluate history of heart disease and obtain baseline ECG in at‑risk patients.
• Concomitant CNS depressants: avoid or use caution with alcohol, benzodiazepines, or opioids due to enhanced sedation.
• Glaucoma: monitor intra‑ocular pressure in patients with narrow‑angle glaucoma.
• Elderly patients: start with low dose and monitor for anticholinergic effects and falls.
• Suicide risk: assess depressive severity and monitor for emergent suicidal thoughts, especially early in therapy.
• Store at ambient temperature: keep tablets below 25 °C in the original container, protected from moisture and light.

Nortriptyline interacts with several medicines; awareness of these interactions helps prevent adverse events.

Major Interactions (Avoid)

• MAO inhibitors: concurrent use can cause hypertensive crisis or serotonin syndrome.
• SSRIs/SNRIs: increased risk of serotonin syndrome when combined.
• Anticholinergic drugs: additive anticholinergic burden may exacerbate dry mouth, constipation, and urinary retention.

Moderate Interactions (Monitor Closely)

• CYP2D6 inhibitors (e.g., fluoxetine, quinidine): may raise nortriptyline plasma levels, requiring dose adjustment.
• CYP1A2 inducers (e.g., carbamazepine, smoking): may reduce drug effectiveness.
• Diuretics: can enhance orthostatic hypotension.
• Anticoagulants: may increase bleeding risk; monitor INR.