Nortriptyline
A tricyclic antidepressant, the main active metabolite of amitriptyline, used for depression and nerve pain.
Drug card
- How it works
- Blocking norepinephrine and serotonin reuptake, plus several receptors
- Used for
- Depression
- Nerve pain (neuropathic pain)
- Known for
- Dry mouth, blurred vision and constipation
- Drowsiness
- Its name
- -triptyline means a tricyclic antidepressant (amitriptyline type)
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does nortriptyline work?
Nortriptyline, the principal active metabolite of amitriptyline, blocks norepinephrine reuptake more strongly than serotonin reuptake. It is less anticholinergic than amitriptyline but more antihistaminic. CYP2D6 clears it, and because that enzyme's activity is inherited and varies, blood levels differ widely between people.
Like other tricyclic antidepressants: Tricyclics block the norepinephrine (NET) and serotonin (SERT) transporters, so both transmitters build up in the synapse; how this relieves depression is not fully known. They also block muscarinic, H1-histamine and α1-adrenergic receptors, giving dry mouth, sedation and postural hypotension, and they block sodium channels, which widens the QRS complex and makes overdose dangerous to the heart.
Uses
What is nortriptyline used for?
- Depression
- Nerve pain (neuropathic pain)
Side effects
Side effects of nortriptyline
- Dry mouth, blurred vision and constipationKnown for
- DrowsinessKnown for
- Difficulty passing urine
- Dizziness on standing
- Fast heartbeat
- Heart block and arrhythmiasSerious
- Confusion, especially in older people
- SeizuresSerious
- Suicidal thoughts in children and young adultsSerious
- Low sodium (SIADH)Serious
- Jaundice and liver problems, rarelySerious
- Bone marrow suppression, including agranulocytosisSerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Contraindicated in the recovery period after a heart attack; take care with any heart disease.
- Do not combine with an MAOI, or start it within 14 days of stopping one, because of serotonin syndrome.
- Blood levels can be measured to guide dosing, which helps when CYP2D6 inhibitors are added.
Good to know: Less anticholinergic than its parent drug amitriptyline; its blood level can be measured to keep it within a target range.
Remember it
A way to remember it
Three rings, three Cs: convulsions, coma and cardiotoxicity in overdose.
Tricyclics are named for their three-ring structure. In overdose they cause seizures, coma and dangerous heart rhythms with a widened QRS complex, so only small supplies are given to people at risk.
A mnemonic widely used in teaching
Its name
-triptyline means tricyclic antidepressant (amitriptyline type)
Amitriptyline and nortriptyline share it. Imipramine and clomipramine, also tricyclic antidepressants, end in -pramine, and -triptan (sumatriptan) marks migraine drugs.
- Every drug name stem
Its class
Tricyclic antidepressants
Other tricyclic antidepressants with a card:
Easily mixed up with serotonin-norepinephrine reuptake inhibitors and monoamine oxidase inhibitors.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Nortriptyline hydrochloride: label (DailyMed)
- Nortriptyline (NCI Thesaurus)
- Nortriptyline (NHS)
- Nortriptyline 25 mg film-coated tablets: SmPC (emc)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Depression, anxiety and sleep
Nortriptyline is one of 15 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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