[Insufficient effect of nortriptyline in a rapid metabolizer of sparteine]

A 61-year old woman suffering from depression was treated with 150 mg nortriptyline daily for eight weeks by her general practitioner. In spite of this dose, her S-nortriptyline was only 100 nmol/1 (recommended range: 225-600 nmol/1), and she remained depressed and was admitted to hospital. A sparteine test gave a metabolic ratio of 0.06, hence the patient was classified as a very rapid extensive metabolizer. Her nortriptyline dose was increased to 250 mg/day and the S-nortriptyline rose to 528 nmol/l. After eight weeks of sufficient nortriptyline treatment, the patient was still depressed. The patient recovered completely after a series of five electroconvulsive treatments.