Nortriptyline (Pamelor) is a tricyclic antidepressant approved by the FDA only for the treatment of depression. However, with the introduction of SSRI family of antidepressants such as fluoxetine (Prozac) which have fewer side effects, the use of tricyclic antidepressants for depression has declined.
Tricyclic antidepressants are still in wide use, but mostly for the treatment of headaches and pain. Nortriptyline is very similar to amitriptyline (Elavil) and is thought to cause fewer and milder side effects, although this has not been proven. This could be due to the fact that amitriptyline is broken down into nortriptyline, which is the active metabolite. Amitriptyline tends to be more sedating, which can be useful in patients with insomnia.
There are no good blinded studies of nortriptyline for the prevention of migraines and they are not likely to be done. We assume it is as good as amitriptyline, although studies of amitriptyline also lack in size and scientific rigor.
There are many trials of amitriptyline and nortriptyline for various pain conditions, but they are also not up to our modern standards. Amitriptyline was approved in the US in 1961.
Besides sedation, nortriptyline can cause dry mouth, constipation, urinary retention in older patients, and other side effects. The dose to treat migraines and pain is usually lower than the dose used to treat depression. Pain and headaches sometimes respond to as little as 10 or 25 mg while for depression, the dose goes up to 100 mg and higher.
In short-term studies of major depression, antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults. This is less likely to occur when treating pain, but many pain patients also experience depression.
