Non sedating tricyclic antidepressants
Named for their three-ring chemical structure, tricyclic antidepressants work by correcting chemical imbalances in the brain.
But because they also affect other chemicals throughout the body, these drugs may produce many unwanted side effects.
If TCAs are stopped suddenly without tapering, patients can experience a withdrawal syndrome characterised by some or all of the following: gastrointestinal disturbances, malaise, chills, anxiety, agitation, sleep disturbances, parkinsonism and mania or hypomania (Dilsaver, 1994).
Most of these symptoms are associated with cholinergic rebound and can be managed by gradual tapering over at least four weeks, or as long as six months in patients who have been receiving long term maintenance therapy.
Amitriptyline and nortriptyline are the most commonly prescribed TCAs in New Zealand, and in general nortriptyline is the preferred agent, as it is less likely to cause troublesome adverse effects.
Other tricyclic antidepressants might be more appropriate for depressed people with low energy.
The recommended dosage depends on many factors, including the patient's age, weight, general health and symptoms.
SSRIs (NNT 6.7) and venlafaxine (NNT 4.1 - 5.5) do not appear to be as effective as TCAs (Gilron, 2006).
The starting dose of TCA is 10 - 25 mg at night or in divided doses every 12 hours.