What is the recommended dosage and usage of Nortriptyline for treating depression and chronic pain?

Nortriptyline Dosage and Usage for Depression and Chronic Pain

For depression treatment, nortriptyline should be started at 25 mg at bedtime and increased by 25 mg every 3-7 days as tolerated, with a maximum dosage of 150 mg/day. For chronic pain management, start with 10-25 mg at bedtime and titrate more gradually to 25-100 mg/day. 1, 2, 3

Dosage for Depression

• Start with 25 mg at bedtime or 25 mg 3-4 times daily 3
• Gradually increase by 25 mg every 3-7 days as tolerated 1
• Maximum recommended dosage: 150 mg/day 1, 3
• Alternative regimen: The total daily dose may be given once daily at bedtime 3
• When doses exceed 100 mg daily, plasma levels should be monitored and maintained in the optimal range of 50-150 ng/mL 3
• For elderly patients: Use lower dosages (30-50 mg/day in divided doses) 3

Dosage for Chronic Pain

• Start with lower doses: 10-25 mg at bedtime 2
• Increase gradually by 25 mg every 3-7 days as tolerated 1
• Effective dose range for neuropathic pain: 25-100 mg/day 2
• Duration of adequate trial: 6-8 weeks with at least 2 weeks at maximum tolerated dosage 1
• For elderly patients: Start at lower doses and titrate more slowly 1

Pharmacokinetic Considerations

• Optimal therapeutic plasma concentrations: 50-150 ng/mL 3
• Higher concentrations (>200 μg/L) may be associated with poorer clinical response and more adverse effects 3, 4
• Plasma concentrations should be monitored when approaching maximum doses 2, 3
• Single-dose pharmacokinetic data can help predict steady-state plasma levels and potentially clinical response 4

Clinical Efficacy

• For depression: Significant improvement may be observed within 1-2 weeks with appropriate dosing 5, 6
• For neuropathic pain: Nortriptyline is considered a first-line option for certain types of neuropathic pain 1
• Evidence suggests similar efficacy to other tricyclic antidepressants (like amitriptyline) for pain management but with a better side effect profile 2, 7
• For HIV-associated neuropathic pain: Consider as a second-line option after gabapentin 1

Common Side Effects and Precautions

• Most common side effects: sedation, dry mouth, constipation, urinary retention, orthostatic hypotension 2, 3
• Nortriptyline is less sedating and has fewer anticholinergic effects than amitriptyline but more than desipramine 1, 2
• Orthostatic hypotension may occur, particularly with higher initial doses 5, 6
• ECG monitoring may be warranted in elderly patients or those with cardiac conditions 2, 3
• Higher plasma concentrations of the active metabolite 10-hydroxy nortriptyline have been reported in older patients and may be associated with cardiotoxicity 3

Special Populations

• Elderly patients: Start with lower doses (10-25 mg/day) and titrate more slowly 3, 8
• A single 50 mg test dose with plasma level measurement at 24 hours can help predict appropriate maintenance dosing in elderly patients 8
• Not recommended for pediatric patients 3
• Use with caution in patients with cardiac conditions, as it can affect cardiac conduction 2

Monitoring

• Clinical response should be the primary determinant of dosage changes 3
• Monitor for side effects, particularly orthostatic hypotension, especially when initiating therapy 5, 6
• When doses exceed 100 mg/day, monitor plasma levels to maintain within 50-150 ng/mL 3
• If minor side effects develop, reduce the dosage; discontinue promptly if serious adverse effects occur 3

Maintenance Therapy

• Following remission of depression, maintenance medication may be required for a longer period at the lowest dose that maintains remission 3
• For chronic pain management, regular reassessment of efficacy and side effects is recommended 1