Nortriptyline Dosage and Treatment Regimen
The recommended dosage of nortriptyline for adults is 25 mg 3-4 times daily, with treatment initiated at a low level and gradually increased as required, with an alternative regimen of administering the total daily dose once daily at bedtime. 1
Initial Dosing and Titration
- For most adults, nortriptyline should be started at 10-25 mg at bedtime and gradually increased by 25 mg every 3-7 days as tolerated to minimize side effects 2, 3
- The American Geriatrics Society recommends lower starting doses for elderly patients (30-50 mg/day in divided doses) 3
- The FDA label specifically states that lower than usual dosages are recommended for elderly patients and outpatients 1
Maximum Dosage and Plasma Level Monitoring
- Doses above 100 mg daily require plasma level monitoring to maintain nortriptyline in the optimal range of 50-150 ng/mL 1
- Doses above 150 mg per day are not recommended according to the FDA label 1
- Optimal therapeutic responses have been associated with plasma concentrations of 50-150 ng/mL, with higher concentrations potentially associated with more adverse experiences 1, 4
Administration Options
- Nortriptyline can be administered as divided doses (25 mg 3-4 times daily) or as a single daily dose, typically at bedtime 1
- For pain management, nortriptyline is commonly administered at bedtime with doses ranging from 10-25 mg initially, increasing to 25-100 mg as tolerated 2
- For diabetic peripheral neuropathy specifically, nortriptyline is typically dosed at 25-75 mg at bedtime 3
Special Considerations
- For patients with cardiac disease, the American College of Cardiology recommends limiting doses to less than 100 mg/day when possible 3
- The American Heart Association recommends obtaining ECG screening for patients over 40 years before starting treatment 3
- Clinical findings should predominate over plasma concentrations as primary determinants of dosage changes 1
- Maintenance medication may be required for a longer period of time at the lowest dose that will maintain remission 1
Monitoring and Dose Adjustment
- The American College of Physicians recommends assessing treatment response after 2-4 weeks at therapeutic doses 3
- If minor side effects develop, the dosage should be reduced 1
- The drug should be discontinued promptly if adverse effects of a serious nature or allergic manifestations occur 1
- For patients with neuropathic pain who achieve partial relief, consider adding another first-line medication from a different class (e.g., gabapentin or pregabalin) 3
- If inadequate pain relief occurs after an adequate trial, consider switching to an alternative first-line medication 3
Common Side Effects
- Common adverse effects include anticholinergic symptoms such as dry mouth, constipation, and urinary retention 3
- Nortriptyline has fewer anticholinergic side effects than tertiary amines like amitriptyline, making it preferable for many patients 3
- Orthostatic hypotension can occur, particularly with higher initial doses, though this appears to be manageable in most patients 5