nortriptyline (Pamelor)

Nortriptyline is in the class of drugs called tricyclic antidepressants (TCAs) and is used for treating depression. Other drugs in the same class include:

• amitriptyline (Endep, Elavil),
• clomipramine (Anafranil),
• doxepin (Sinequan),
• imipramine (Tofranil),
• trimipramine (Surmontil),
• amoxapine (Amoxapine),
• desipramine (Norpramin), and
• protriptyline (Vivactil).

Individuals with depression may have an imbalance in neurotransmitters, chemicals that nerves make and use to communicate with other nerves. Like all TCAs, nortriptyline increases levels of norepinephrine and serotonin, two neurotransmitters, and blocks the action of acetylcholine, another neurotransmitter. It is believed that by restoring the balance of these different neurotransmitters in the brain depression is alleviated (for example, the mood is elevated).

Nortriptyline was approved by the FDA in November 1964.

What brand names are available for nortriptyline?

Pamelor (The brand name Aventyl has been discontinued in the US)

Is nortriptyline available as a generic drug?

Yes

Do I need a prescription for nortriptyline?

Yes

The most commonly encountered side effects associated with nortriptyline include:

• Fast heart rate
• Blurred vision
• Urinary retention
• Dry mouth
• Constipation
• Weight gain or loss
• Low blood pressure on standing (orthostatic hypotension)

Rare side effects include:

• Rash
• Hives
• Seizures
• Hepatitis

Nortriptyline also can cause elevated pressure in the eyes of some patients with glaucoma.

Overdoses of nortriptyline can cause life-threatening abnormal heart rhythms or seizures.

If nortriptyline is discontinued abruptly, headache, nausea, and general discomfort may occur. Therefore, it is recommended that the dose of antidepressant be reduced gradually when therapy is discontinued.

Antidepressants increased the risk of suicidal thinking and behavior in short-term studies in children and adolescents with depression and other psychiatric disorders. Anyone considering the use of nortriptyline or any other antidepressant in a child or adolescent must balance this risk with the clinical need. Patients who are started on therapy should be closely observed for clinical worsening, suicidal thinking or behavior, and unusual changes in behavior.

Nortriptyline hydrochloride is not recommended for children.

Nortriptyline hydrochloride (nortriptyline hydrochloride (nortriptyline hydrochloride (nortriptyline hydrochloride capsules) capsules) capsules) is administered orally. Lower than usual dosages are recommended for elderly patients and adolescents. Lower dosages are also recommended for outpatients than for hospitalized patients who will be under close supervision. The physician should initiate dosage at a low level and increase it gradually, noting carefully the clinical response and any evidence of intolerance. Following remission, maintenance medication may be required for a longer period of time at the lowest dose that will maintain remission.

If a patient develops minor side effects, the dosage should be reduced. The drug should be discontinued promptly if adverse effects of a serious nature or allergic manifestations occur.

Usual Adult Dose

25 mg three or four times daily; dosage should begin at a low level and be increased as required. As an alternative regimen, the total daily dosage may be given once a day. When doses above 100 mg daily are administered, plasma levels of nortriptyline should be monitored and maintained in the optimum range of 50 to 150 ng/mL. Doses above 150 mg/day are not recommended.

Elderly and Adolescent Patients

30 to 50 mg/day, in divided doses, or the total daily dosage may be given once a day.

TCAs, including nortriptyline, should not be used concurrently with a monoamine oxidase inhibitors such as tranylcypromine (Parnate), isocarboxazid (Marplan), phenelzine (Nardil), and procarbazine (Matulane) because of the possibility of hyperpyretic crises (high fever), convulsions, and even death.

Cimetidine (Tagamet) can increase blood levels of nortriptyline in the blood by interfering with the metabolism (breakdown) of nortriptyline by the liver. Increased levels of nortriptyline may possibly lead to side effects. Other drugs which share this effect on nortriptyline include propafenone (Rythmol), flecainide (Tonocard), quinidine (Quinidex, Quinaglute), and fluoxetine (Prozac).

Nortriptyline exaggerates the effects of other medications and drugs that slow the activity of the brain, such as alcohol, barbiturates, benzodiazepines, for example lorazepam (Ativan), clonazepam (Klonopin), and diazepam (Valium), as well as narcotics. Reserpine (Harmonyl), stimulates the brain when given to patients taking nortriptyline.

Combining nortriptyline or other TCAs with drugs that block acetylcholine (anticholinergic drugs) can cause constipation and even paralyze the intestine (paralytic ileus). Dangerous elevations in blood pressure may occur if TCA's are combined with clonidine (Catapres, Catapres-TTS).

Safe use of nortriptyline during pregnancy has not been established. Doctors may use nortriptyline in pregnant women if its benefits are deemed to outweigh its potential but unknown risks.

Safe use of nortriptyline during lactation has not been established. It is not known if nortriptyline is secreted in breast milk.

What preparations of nortriptyline are available?

10, 25, 50, and 75 mg. Oral solution: 10 mg/teaspoon

How should I keep nortriptyline stored?

Nortriptyline should be stored below 30 C (86 F) in a tight, light resistant container.