Nortriptyline

Indications

Nortriptyline is used for: Depression, Nocturnal enuresis

Adult Dose

Oral Depression Adult: 75-100 mg/day in 3 or 4 divided doses. Max: 150 mg/day in severe depression. Elderly: 30-50 mg/day in divided doses. Hepatic impairment: Administer lower dose and titrate at a slower rate

Child Dose

Oral Depression Child: Adolescent: 30-50 mg/day in divided doses. Nocturnal enuresis Child: 6-7 yr (20-25 kg): 10 mg; 8-11 yr (25-35kg): 10-20 mg; >11 yr (35-54 kg): 25-35 mg. All doses are given 30 minutes before bedtime and treatment should continue for not >3 mth.

Renal Dose

Administration

May be taken with or without food.

Contra Indications

Mania, recent MI, arrhythmias (particularly heart block); severe liver disease; children <6 yr.

Precautions

Not intended for treatment of bipolar depression. Avoid abrupt withdrawal. Patient at risk of seizures, w/ DM, narrow angle glaucoma, urinary retention, prostatic hyperplasia, chronic constipation, history of CV disease. Renal and hepatic impairment. Elderly, childn. Pregnancy and lactation. Patient Counselling May impair ability to perform tasks requiring mental and physical alertness (e.g. driving or operating machinery). Monitoring Parameters Monitor BP and pulse rate prior to or during initial therapy, wt. Monitor for emergence of serotonin syndrome. Closely monitor for clinical worsening, suicidality and unusual changes in behaviour. Lactation: Excreted in breast milk; do not nurse (AAP states effect on nursing infants is unknown but may be of concern)

Pregnancy-Lactation

Interactions

Increased risk of serotonin syndrome w/ SSRIs, SNRIs, TCAs, triptans, fentanyl, lithium, tramadol, tryptophan, buspirone. May reduce antihypertensive effect of bethanidine, guanethidine, debrisoquine, clonidine. May increase metabolism w/ barbiturates. Increased risk of arrhythmias and hypotension w/ anaesth. Increased plasma level w/ fluoxetine. Potentially Fatal: Increased risk of serotonin syndrome w/ MAOIs, linezolid and methylene blue.

Adverse Effects

Side effects of Nortriptyline : Hypotension, HTN, tachycardia, palpitation, MI, arrhythmias, heart block, stroke; confusional states w/ hallucinations, disorientation, delusions; anxiety, restlessness, agitation; insomnia, panic, nightmares; hypomania; exacerbation of psychosis; suicidal ideation and behaviours; numbness, tingling, paraesthesia; incoordination, ataxia, tremors; peripheral neuropathy; extrapyramidal symptoms; seizures; tinnitus, dry mouth, blurred vision, accommodation disturbances, mydriasis; constipation, paralytic ileus; urinary retention, delayed micturition, dilation of the urinary tract. Rash, itching, urticaria, photosensitisation; oedema (general or of face and tongue); bone-marrow depression including agranulocytosis, aplastic anaemia, eosinophilia, thrombocytopenia. Nausea, vomiting, anorexia, epigastric distress, diarrhoea, peculiar taste, stomatitis, abdominal cramps, malaise, jaundice, hepatitis and liver necrosis. Sweating, flushing, urinary frequency, nocturia, drowsiness, dizziness, weakness, fatigue, headache, parotid swelling, alopecia. Gynaecomastia, breast enlargement and galactorrhoea; increased or decreased libido, impotence, testicular swelling; elevation or reduction of blood sugar levels; inappropriate secretion of antidiuretic hormone syndrome. Wt gain or loss, altered liver function. Rarely, associated sublingual adenitis or gingivitis. Potentially Fatal: Rare, blood dyscrasias.

Mechanism of Action

Nortriptyline, a dibenzocycloheptadiene tricyclic antidepressant, is the primary active metabolite of amitriptyline. It increases synaptic concentration of serotonin and/or norepinephrine in the CNS by blocking the neuronal reuptake of norepinephrine and serotonin.