The average elimination half-life of nortriptyline in adults is 30 hours with a range of 18 to 56 hours. The mean half-life in children is 18 hours. The therapeutic serum concentration is considered to be in the range of 190 to 570 nmol/L. Routine serum drug concentration monitoring is not warranted but may be useful in assessing adherence, suspected toxicity or lack of effect. Recommended therapeutic trough levels range from 170 to 495 nmol/L. Ideally, the trough level should be taken 12 hours following administration of the last dose.

Nortriptyline is contraindicated in patients who have known hypersensitivity to the drug. Cross-sensitivity between nortriptyline and related TCAs is possible.

Hypertension, tachycardia, confusion, hyperpyretic crisis, severe seizures and death have occurred in patients receiving TCAs and MAO inhibiting drugs simultaneously. Normally, when nortriptyline must be substituted for an MAO inhibitor or vice versa, a minimum of 14 days should elapse after the initial drug is discontinued before the new drug is cautiously started; however, patients with refractory depression have received combination therapy without significant adverse effects, under certain strict conditions and under the supervision of prescribers experienced with such therapy.

Nortriptyline is not recommended during the acute recovery phase following myocardial infarction or in the presence of congestive heart failure