Nortriptyline (Pamelor)

What it treats

Nortriptyline is approved by the U.S. Food and Drug Administration to treat depression.

In everyday practice it's also used off-label for chronic pain conditions (neuropathic pain, fibromyalgia), migraine prevention, and sometimes for chronic tension headache. Off-label means a purpose the label doesn't formally list even though evidence and practice support it.

How it works

Nortriptyline affects the brain's chemical messengers norepinephrine and, to a lesser extent, serotonin. It's grouped with the tricyclic antidepressants, an older family of drugs that share a three-ring chemical structure.

The antidepressant effect isn't from the first dose. It comes from slower changes in the brain over the following weeks. The pain benefit at lower doses seems to work through a somewhat different route, which is why the doses for pain and the doses for depression aren't always the same.

Receptor mechanism (detail)

Nortriptyline is a secondary-amine tricyclic antidepressant. It's a norepinephrine reuptake inhibitor with weaker serotonin reuptake activity (NET greater than SERT). Compared with tertiary amines like amitriptyline and imipramine, it has less blockade at muscarinic, H1, and alpha-1 receptors, so dry mouth, sedation, and orthostatic hypotension are lighter. The tricyclic effects on cardiac sodium channels are still present, which is why ECG and overdose considerations don't go away.

Potency and typical dosing pattern

Ranges are typical framework only, not a prescription for any individual.

Starting is often 25 mg at bedtime. Usual range for depression is 50 to 150 mg per day, guided by response and serum level. The therapeutic serum window is 50 to 150 ng/mL, a real target checked with a trough level once steady state is reached (about a week at a stable dose). For pain and migraine prevention, lower doses (10 to 50 mg at bedtime) are common.

Safety monitoring

• ECG at baseline, and periodically at higher doses or with cardiac risk factors. Tricyclics can prolong QRS, PR, and QTc.
• Serum nortriptyline level. Trough draw, aiming for 50 to 150 ng/mL. Levels above 150 ng/mL don't work better and raise cardiac risk.
• Overdose danger. Tricyclics have a narrow therapeutic index; even modest overdoses can cause fatal arrhythmias.
• Anticholinergic burden, lighter than amitriptyline but not absent.
• Orthostatic vitals, especially in older adults.
• Suicidality in the first 4 weeks, especially under age 25 (FDA boxed warning).
• Serotonin syndrome, avoid MAOIs.
• Reassess at 2, 4, and 6 to 8 weeks.

What to expect

Common side effects

Common side effects include:

• Dry mouth.
• Constipation.
• Drowsiness at first, often easing.
• Blurred vision.
• Weight gain.
• Dizziness on standing.

Several of these come from the anticholinergic effect. They tend to be milder with nortriptyline than with amitriptyline. If a side effect is severe, or it isn't improving, that's a conversation to have with the prescriber rather than a reason to stop on your own.

Serious side effects and warnings

Serious problems are uncommon, but a few are worth knowing.

Boxed warning. Like all antidepressants, nortriptyline carries an FDA boxed warning that it can increase suicidal thoughts and behaviors in children, teenagers, and young adults under 25, especially in the first weeks of treatment or after a dose change. This doesn't mean the medication harms most people. It means the early period deserves close attention, and that any worsening of mood, agitation, or new thoughts of self-harm should prompt contact with the prescriber promptly.

• Effects on heart rhythm. Tricyclics can affect cardiac conduction. That's why a baseline ECG matters and why doses aren't pushed above what the level requires.
• Danger in overdose. Tricyclics are more dangerous than newer antidepressants if taken in overdose, which a prescriber weighs when choosing and prescribing them.
• A drop in blood pressure on standing can cause dizziness or falls, especially in older adults.
• Serotonin syndrome. Do not combine with MAOIs. A washout is needed when switching.
• Anticholinergic burden. Lighter than tertiary tricyclics, but still real. In older adults, it can mean confusion, urinary retention, and falls.

Sexual side effects

Nortriptyline can reduce sex drive and make orgasm or erection more difficult. It's generally reported less often with nortriptyline than with SSRIs, but it's not zero. If sexual side effects appear, they're worth raising with the prescriber because there are options.

Weight, appetite, and sleep

Nortriptyline can increase appetite and cause weight gain, though usually less than amitriptyline. It's somewhat sedating, which is why it's taken at bedtime. Sleep quality is often better once the medication is settled in.

Starting and dosing basics

This section is general background, not a dosing instruction for any individual. The right dose is a decision for a prescriber.

Nortriptyline comes as capsules and as an oral solution. For depression, a starting dose of 25 mg at bedtime is common, with steps up every few days to a week. A serum level is drawn after about a week at a stable dose to see where a person sits in the 50 to 150 ng/mL window. For pain and migraine prevention, lower doses at bedtime are typical.

Missed doses and interactions

If you miss a dose, the general guidance is to take it when you remember, unless it's almost time for the next dose. In that case, skip the missed dose and carry on. Don't take two doses to make up for one.

A few interactions matter. Nortriptyline must not be combined with MAOI antidepressants, and a gap is needed when switching between them. Alcohol and other sedating medications add to drowsiness. CYP2D6 inhibitors (fluoxetine, paroxetine, bupropion) can raise nortriptyline levels, which is one reason the serum level matters when other medications change. Give every prescriber and pharmacist a full list of your medications and supplements, including over-the-counter ones.

Stopping and tapering

Nortriptyline isn't a controlled substance and isn't habit-forming in the usual sense. It doesn't cause cravings or compulsive use.

The body does adjust to it, though, and stopping abruptly after regular use can cause discontinuation symptoms: nausea, dizziness, sleep disturbance, and a return of low mood. A gradual taper planned with a prescriber avoids most of this.

Pregnancy and breastfeeding

This is an area where individual circumstances matter and the decision belongs with a clinician. Untreated depression carries its own risks during pregnancy, and nortriptyline also passes into breast milk in small amounts. Nortriptyline actually has a longer record of use in pregnancy than most newer antidepressants, which sometimes weighs into the decision. Anyone who is pregnant, planning a pregnancy, or breastfeeding should talk it through with their prescriber so the specific risks and benefits can be weighed for their situation.

Cost and generic availability

Nortriptyline has been available as a generic for many years and is inexpensive. Generic nortriptyline contains the same active medication as the brand name Pamelor and works the same way. Most insurance plans cover it.

Common questions

Why check a serum level for nortriptyline when we don't for most antidepressants? Nortriptyline has a real therapeutic window, 50 to 150 ng/mL, with both under-dosing and over-dosing possible outside it. Higher levels don't work better and can raise cardiac risk. A level guides dose in a way that isn't available for SSRIs.

Is nortriptyline safer than amitriptyline? For older adults, generally yes. It has a lighter anticholinergic and orthostatic profile. It's still a tricyclic, though, with the same overdose considerations.

Why is it used for pain? Tricyclics have real evidence for neuropathic pain and migraine prevention, often at lower doses than are used for depression. The pain benefit doesn't hinge on the mood benefit.

Will it make me gain weight? It can. Weight gain is usually less than with amitriptyline but not absent. If it becomes a concern, raise it with your prescriber.

Is it addictive? No. It's not a controlled substance and doesn't cause cravings. Stopping should still be done gradually.

Questions to ask your prescriber

• What are we treating with this, and how will we know it's working?
• Should we check a serum level, and when?
• Given my other medications, are there interactions we need to plan around?
• Which side effects should I expect, and which ones should I call about?
• If we decide to stop it later, how would we do that safely?

Sources

This guide draws on current prescribing information and public health references and current as of June 8, 2026. It is reviewed for clinical accuracy and updated as guidance changes.

• U.S. Food and Drug Administration. Nortriptyline hydrochloride (Pamelor) prescribing information.
• MedlinePlus, U.S. National Library of Medicine. Nortriptyline.
• National Institute of Mental Health. Mental health medications.
• American Psychiatric Association. Practice Guideline for the Treatment of Patients with Major Depressive Disorder.
• National Institute for Health and Care Excellence (NICE). NG222, Depression in adults.
• American Geriatrics Society. Beers Criteria for Potentially Inappropriate Medication Use in Older Adults (2023).