imipramine hydrochloride: clinical use

Prescribing considerations

• Assess suicide and overdose risk; tricyclic toxicity in overdose can be severe, particularly in children.
• Use particular caution in older people because anticholinergic, neurological, postural and cardiovascular effects are more likely.
• Review epilepsy or other seizure risk, renal or hepatic disease, constipation, raised intraocular pressure, urinary symptoms, thyroid disease and concurrent anaesthesia.
• Avoid abrupt withdrawal because discontinuation symptoms can occur.
• The oral solution contains sorbitol, propylene glycol and parabens; it is unsuitable in hereditary fructose intolerance.

Contraindications and cautions

• Hypersensitivity to imipramine, listed excipients or related dibenzazepine tricyclic antidepressants.
• Recent myocardial infarction, heart block or another cardiac arrhythmia.
• Mania, severe liver disease, narrow-angle glaucoma or urinary retention.
• Current or recent monoamine oxidase inhibitor treatment, including concomitant moclobemide.
• Known or previous porphyria.
• Use below the minimum age stated in the product licence.

Monitoring

• Monitor mood, suicidal thinking and unusual behavioural change, especially early in treatment and after treatment changes.
• Check blood pressure before treatment and assess postural symptoms.
• Consider blood counts, particularly early in treatment or if fever, sore throat or infection develops.
• Monitor hepatic enzymes in liver disease and cardiac function in older people.
• Consider hyponatraemia if drowsiness, confusion or convulsions develop.
• For long-term treatment, encourage dental review because anticholinergic dry mouth may increase caries risk.

Clinical pharmacology

Imipramine is a mixed noradrenaline and serotonin reuptake inhibitor with an active metabolite, desmethylimipramine. It is rapidly absorbed orally, extensively metabolised in the liver and highly protein bound; reduced metabolic clearance can increase exposure in older people.

Formulation and product differences

• The selected product is a clear, colourless, banana-flavoured oral solution.
• It contains sorbitol, propylene glycol, methyl paraben and propyl paraben.
• Keep the solution tightly closed, store it below the stated temperature limit and discard it after the manufacturer's specified in-use period.

Oral solution

Route: Oral

Strengths: 25 mg/5 mL