Tricyclic antidepressant Pregnancy: There is no evidence of safety in human pregnancy and there have been isolated reports of a possible connection between tricyclic antidepressants and developmental disorders in the foetus; treatment should be avoided during pregnancy unless the anticipated benefits justify the potential risk. Neonates whose mothers took imipramine until delivery have developed dyspnoea, lethargy, colic, irritability, hypotension or hypertension, tremor or spasms in the first hours or days. If possible withdraw gradually at least 7 weeks before the calculated date of confinement. Imipramine and desmethylimipramine pass into breast milk in small quantities - withdraw gradually or advise the mother to cease breast-feeding. (SPC 4.6)

Imipramine hydrochloride

Imipramine hydrochloride is a tricyclic antidepressant used for depression and for nocturnal enuresis in children.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Depression: 25 mg up to three times daily, increasing stepwise to 150-200 mg daily - this should be reached by the end of the first week and maintained until definite improvement has occurred

Route: Oral

Frequency: Up to three times daily

No absolute maximum dose is stated in the SPC. Maintenance: the subsequent maintenance dose should be individually determined by gradually reducing the dosage, usually to about 50-100 mg daily. In patients in hospital (i.e. severe cases) the dose may be increased to 100 mg three times daily until a distinct improvement is seen, with the maintenance dose then determined individually by reduction, usually to about 100 mg daily. Elderly: patients over 60 years may respond to lower doses - initiate with 10 mg daily, gradually increasing to 30-50 mg daily; the optimum dose should be reached after about 10 days and then continued until the end of treatment. Contraindicated in infants and children under 6 years. eMC SPC section 4.2.

Paediatric dose

Route: Oral

Frequency: Once daily, taken just before bedtime

Max: A daily dose of 2.5 mg/kg should not be exceeded in children

Nocturnal enuresis only; not for use in children under 6 years. Age/weight bands from SPC 4.2: 6-7 years (weight 20-25 kg) 25 mg daily; 8-11 years (25-35 kg) 25-50 mg daily; over 11 years (35-54 kg) 50-75 mg daily. The SPC states a per-kg maximum only, not a per-kg dose, so dosePerKg is left null. The maximum period of treatment should not exceed three months and withdrawal should be gradual; if relapse occurs, a further course should not be started until a full physical examination has been made.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to imipramine or excipients, or cross-sensitivity to other tricyclic antidepressants of the dibenzazepine group
Recent myocardial infarction
Any degree of heart block or other cardiac arrhythmias
Mania
Severe liver disease
Narrow angle glaucoma
Infants and children under 6 years old
Retention of urine
Concurrent use in patients receiving, or within 3 weeks of stopping, monoamine oxidase inhibitors; concomitant selective reversible MAO-A inhibitors such as moclobemide
Porphyria (imipramine is reported to be porphyrinogenic)

Side effects

Anticholinergic effects (frequent) - dry mouth, sweating, constipation, disorders of visual accommodation, blurred vision, hot flushes; occasionally disturbances of micturition
Cardiovascular (frequent) - sinus tachycardia, clinically irrelevant ECG changes and postural hypotension, particularly at high dosage or in pre-existing heart disease; occasionally arrhythmias and conduction disorders
Tremor (frequent); occasionally paraesthesia, headache, dizziness; rarely epileptic seizures
Fatigue, drowsiness, restlessness, confusion, disorientation and hallucination (particularly in elderly patients and those with Parkinson's disease); swings from depression to hypomania or mania
Weight gain (frequent); occasionally disturbances of libido, impotence or abnormal ejaculation
Nausea, vomiting, anorexia; occasionally elevated transaminases

Interactions

Monoamine oxidase inhibitors - contraindicated concurrently or within 3 weeks of stopping the MAOI; moclobemide and other reversible MAO-A inhibitors contraindicated (SPC 4.3)
CYP2D6 inhibitors raise TCA plasma levels and can precipitate toxicity in a previously stable patient - quinidine, cimetidine, SSRIs (fluoxetine, sertraline, paroxetine), phenothiazines, and the class 1C antiarrhythmics propafenone and flecainide (US label, Drug Interactions)
Poor CYP2D6 metabolisers have higher than expected TCA plasma concentrations at usual doses (US label, Drug Interactions)

Clinical monograph

How it works

It inhibits reuptake of noradrenaline and serotonin and has antimuscarinic, antihistaminic and alpha-adrenergic blocking actions that account for much of its adverse-effect profile.

Prescribing in practice

Tricyclics are dangerous in overdose with cardiotoxicity and arrhythmia, so assess suicide risk and consider quantities supplied, and avoid in recent myocardial infarction, arrhythmias and heart block.
Antimuscarinic effects cause dry mouth, constipation, blurred vision and urinary retention, and it can cause postural hypotension and lower the seizure threshold.
For childhood nocturnal enuresis follow a children's formulary, treat for a limited period with review, and counsel on overdose danger to household members.

Monitoring

Monitor mood and suicidality, cardiovascular status and antimuscarinic burden, with ECG consideration where cardiac risk is present.

Counselling the patient

Store securely away from children, as overdose is dangerous.
Expect dry mouth, constipation or blurred vision, and rise slowly to avoid dizziness.
Do not stop abruptly; the dose should be reduced gradually under advice.

Evidence & guidelines

Tricyclic antidepressants such as imipramine are long-established treatments, and NICE depression guidance notes their toxicity in overdose relative to newer agents.

Reference: NICE NG28 (children); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

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