DULOXETINE-WGR

What it is

DULOXETINE-WGR enteric capsules come in two strengths and contain enteric coated pellets of duloxetine hydrochloride equivalent to 30 mg or 60 mg of duloxetine. 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 DULOXETINE-WGR is indicated for the treatment of:

— major depressive disorder (MDD) — diabetic peripheral neuropathic pain (DPNP) — generalised anxiety disorder (GAD)

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, and a dose of 30 mg once daily should be used in patients with end stage renal disease. 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. Duloxetine 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. Liver transaminase elevations resulted in the discontinuation of 0.3% of duloxetine-treated patients, with the median time to detection of the transaminase elevation being about two months. Cases of hyponatraemia have been reported very rarely when administering duloxetine, with the majority of these cases occurring in elderly patients, especially when coupled with a recent history of altered fluid balance or conditions pre-disposing to altered fluid balance. 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. When discontinuing duloxetine after more than 1 week of therapy, it is generally recommended that the dose be tapered to minimise the risk of discontinuation symptoms. 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.

Contraindications

Duloxetine 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 DULOXETINE-WGR 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

DULOXETINE-WGR was first listed on the ARTG on 13 August 2024 in two strengths: duloxetine hydrochloride 60 mg enteric capsule and duloxetine hydrochloride 30 mg enteric capsule, both in blister pack format.