DYTREX

What it is

DYTREX contains duloxetine hydrochloride present as enteric coated pellets in two strengths of 30 mg or 60 mg. Duloxetine is a selective serotonin and noradrenaline reuptake inhibitor, and weakly inhibits dopamine uptake with no significant affinity for histaminergic, dopaminergic, cholinergic and adrenergic receptors.

Approved indications DYTREX is indicated for the treatment of:

— Major depressive disorder. — Diabetic peripheral neuropathic pain. — Generalised anxiety disorder.

Dosing overview

For patients in whom initial tolerability may be a concern, such as treatment-naïve patients or those with a history of adverse events with other medications, use of a lower starting dose such as 30 mg once daily for one week before increasing the dose to 60 mg once daily should be considered. When discontinuing duloxetine after more than one week of therapy it is generally recommended that the dose be tapered to minimise the risk of discontinuation symptoms, with the dose of duloxetine reduced by half or administered on alternate days during a period of not less than two weeks.

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/or the emergence of suicidal ideation and behaviours whether or not they are taking antidepressant medications, and this risk may persist until significant remission occurs. 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, either increases or decreases. DYTREX is not indicated for use in patients under the age of 18. DYTREX should ordinarily not be prescribed to patients with evidence of acute or chronic liver disease as it is possible that duloxetine may aggravate pre existing liver disease. Duloxetine increases the risk of elevation of serum transaminase levels. In placebo controlled trials in any indication, elevations of alanine transaminase to >3 times the upper limit of normal occurred in 1.1% of duloxetine-treated patients and in 0.2% of placebo treated patients. SSRIs and SNRIs, including duloxetine, may increase the risk of bleeding events, including gastrointestinal bleeding. Therefore, caution is advised in patients taking duloxetine concomitantly with anticoagulants and/or medicinal products known to affect platelet function (e.g., NSAIDs, aspirin) and in patients with known bleeding tendencies. Duloxetine is associated with an increase in blood pressure in some patients. In placebo controlled clinical trials duloxetine treatment was associated with small increases in systolic blood pressure averaging 2 mm Hg and small increases in diastolic blood pressure averaging 0.5 mm Hg compared to placebo. Withdrawal symptoms when treatment is discontinued are common, particularly if discontinuation is abrupt. In clinical trials, adverse events seen on abrupt treatment discontinuation occurred in approximately 45% of patients treated with duloxetine and 23% of patients taking placebo. The most commonly reported symptoms following abrupt discontinuation of duloxetine in clinical trials have included dizziness, nausea, headache, paraesthesia, fatigue, vomiting, irritability, nightmares, insomnia, diarrhoea, anxiety, hyperhidrosis, vertigo, somnolence and myalgia.

Contraindications

DYTREX is contraindicated in patients with known hypersensitivity to duloxetine or to any of the excipients in the formulation. Duloxetine should not be used in combination with monoamine oxidase inhibitors (MAOI) or the reversible MAOI (RIMA), moclobemide, or within 14 days of discontinuing treatment with a MAOI. Similarly, at least 5 days should be allowed after stopping DYTREX before starting a MAOI. Duloxetine is contraindicated in patients with liver disease resulting in hepatic impairment. Duloxetine should not be used in combination with potent CYP1A2 inhibitors.

Regulatory history

DYTREX 30 mg and 60 mg enteric capsules were first listed on the ARTG on 20 September 2024.