ENTRIP

What it is

ENTRIP is a tricyclic antidepressant with sedative properties. ENTRIP tablets contain amitriptyline hydrochloride in strengths of 10 mg, 25 mg or 50 mg.

Approved indications

— Treatment of major depression. — Nocturnal enuresis where organic pathology has been excluded.

Dosing overview

Dosage should be initiated at a low level and increased gradually, noting carefully the clinical response and any evidence of intolerance.

Key safety warnings

The risk of suicide attempt is inherent in depression and may persist until significant remission occurs. Patients with depression may experience worsening of their depressive symptoms and emergence of suicidal ideation and behaviour whether or not they are taking antidepressant medications. As improvement may not occur during the first few weeks or more of treatment, patients should be closely monitored for clinical worsening and suicidality, especially at the beginning of a course of treatment or at the time of dose changes. Patients and caregivers should be alerted about the need to monitor for any worsening of their condition and the emergence of suicidal ideation or thoughts of harming themselves and to seek medical advice immediately if these symptoms present. Severe cutaneous adverse reactions including drug reaction with eosinophilia and systemic symptoms, which can be life-threatening or fatal, have been reported in association with amitriptyline treatment, with most reactions occurring within 2 to 6 weeks. Patients should be advised of the signs and symptoms and monitored closely for cutaneous reactions. If signs and symptoms suggestive of these reactions appear, ENTRIP should be withdrawn immediately and treatment must not be restarted. Patients with cardiovascular disorders should be watched closely. Tricyclic antidepressant medicines, particularly when given in high doses, have been reported to produce arrhythmias, sinus tachycardia and prolongation of conduction time. Myocardial infarction and stroke have been reported. The 50 mg tablets are indicated only for maintenance treatment of major depression and should not be used in acutely ill patients where there is a risk of suicide. There is an increased risk of completed suicide by overdose with the 50 mg tablet compared with the 25 mg tablet.

Contraindications

ENTRIP is contraindicated in patients who have shown prior hypersensitivity to it. ENTRIP should not be given concurrently with monoamine oxidase inhibitors, including selegiline, as the combination has caused severe convulsions, hyperpyretic crises and death. When substituting ENTRIP for a monoamine oxidase inhibitor, a minimum of 14 days should be allowed to elapse after the latter is discontinued, then ENTRIP should be initiated cautiously with gradual increase in dosage. ENTRIP is contraindicated in patients taking cisapride due to the possibility of adverse cardiac interactions including prolongation of the QT interval, cardiac arrhythmias and conduction system disturbances. ENTRIP is not recommended for use during the acute recovery phase following myocardial infarction.

PBS listing

ENTRIP is listed on the PBS in three strengths: 10 mg, 25 mg and 50 mg tablets, all with unrestricted access. The ex-manufacturer prices are A$2.83 for 10 mg, A$3.01 for 25 mg and A$3.38 for 50 mg.

Regulatory history

ENTRIP amitriptyline hydrochloride tablets were first listed on the ARTG on 27 November 2015, with registrations for 10 mg, 25 mg and 50 mg strengths in both blister pack and bottle pack formats.