Nortriptyline
Mechanism :
Nortriptyline is an antidepressant with sedative effects. Nortriptyline inhibits the membrane pump mechanism responsible for uptake of norepinephrine and serotonin in adrenergic and serotonergic neurons.
Indication :
- Nocturnal enuresis
- Depression
- Hyperactivity
Contraindications :
Nortriptyline is contraindicated in patients who have shown prior hypersensitivity to it and in acute porphyria, hepatic impairment and cardiovascular disease.
Dosing :
Depression:
6-12 years: 1-3 mg/kg/day orally, in 3-4 divided doses.
>12 years: 30-50 mg orally, every day, single or divided dose.
Nocturnal enuresis:
6-7 years: 10 mg orally at bedtime.
8-11 years: 10-20 mg orally at bedtime.
>11 years: 25-35 mg orally at bedtime.
Attention deficit hyperactivity disorder:
0.5 mg/kg/day orally.
Max: 2 mg/kg/day or 100 mg, whichever is lesser.
Adverse Effect :
Mainly anticholinergic effects, sedation, postural hypotension, constipation, blurred vision, tremor, sweating, arrhythmia, increased appetite and weight gain, sexual dysfunction and lowered seizure threshold. Other side effects include, fatigue, lethargy, headache, anxiety, rash, insomnia, dizziness. Paresthesias, tinnitus, eosinophilia, leukopenia, thrombocytopenia, SIADH, agranulocytosis, increased LFTs have also been reported.
Interaction :
MAOIs: Hyperpyretic crises, severe convulsions, and deaths have occurred in patients receiving tricyclic antidepressant and monoamine oxidase inhibiting drugs simultaneously.
OCPs, Calcium Channel Blockers, Cimetidine, Phenothiazines, SSRIs: Plasma concentration of Imipramine increased.
Rifampicin, Anti-Coagulants: Decreased plasma concentration of Imipramine.
Sedatives, Hypotensives, Drugs that prolong QT Interval: Increased effects of these drugs.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function. Start with small dose |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in GFR<10 mL/min |
| HD | Not dialysed. Dose as in GFR<10 mL/min |
| HDF/High flux | Unknown dialysability. Dose as in GFR<10 mL/min |
| CAV/VVHD | Not dialysed. Dose as in normal renal function |
Hepatic Dose :
Since nortriptyline is substantially metabolized in the liver, initiate dosage cautiously in patients with hepatic impairment. No dose adjustments are recommended.