DESFAX

What it is

DESFAX is desvenlafaxine 50 mg and 100 mg modified release tablets. DESFAX is formulated as a modified release tablet for once-a-day oral administration. DESFAX contains the active ingredient desvenlafaxine as the base drug.

Approved indications

— Major depressive disorder, including the prevention of relapse.

Dosing overview

The recommended dose for desvenlafaxine is 50 mg once daily, with or without food. In clinical trials, no additional benefit was demonstrated at doses greater than 50 mg/day. If dose increases are indicated for individual patients, they should occur gradually and at intervals of not less than 7 days, and the maximum dose should not exceed 200 mg/day. The recommended starting dose in patients with severe renal impairment (24-hr CrCl < 30 mL/min) or end-stage renal disease (ESRD) is 50 mg every other day. No adjustment of dose is necessary in patients with mild, moderate, and severe hepatic impairment.

Key safety warnings

Patients with major depression may experience worsening of their depression and/or the emergence of suicidal ideation and behaviour, and antidepressants may have a role in inducing worsening of depression and emergence of suicidality in certain patients during early phases of treatment. Patients should be monitored appropriately and observed closely for clinical worsening and suicidality, especially at the beginning of a course of treatment or at the time of dose changes. The development of a potentially life-threatening serotonin or neuroleptic malignant syndrome (NMS)-like reactions may occur with desvenlafaxine treatment, particularly with concomitant use of other serotonergic drugs (including SSRIs, SNRIs and triptans) and with drugs that impair metabolism of serotonin (such as MAOIs, including reversible MAOIs). Serotonin syndrome symptoms may include mental status changes (such as agitation, confusion, hallucinations, and coma), autonomic instability (such as diaphoresis, tachycardia, labile blood pressure, and hyperthermia), neuromuscular aberrations (such as hyperreflexia, incoordination, myoclonus, tremor) and/or gastrointestinal symptoms (such as nausea, vomiting, and diarrhoea). Increases in blood pressure were observed in some patients in clinical trials, particularly with higher doses. Pre-existing hypertension should be controlled before treatment with desvenlafaxine, and patients receiving desvenlafaxine should have regular monitoring of blood pressure. Upon discontinuation of SNRIs and SSRIs, there have been spontaneous reports of adverse events including dysphoric mood, irritability, agitation, dizziness, sensory disturbances, anxiety, confusion, headache, lethargy, emotional lability, insomnia, hypomania, tinnitus, seizures, visual impairment and hypertension. While these events are generally self-limiting, there have been reports of serious discontinuation symptoms and sometimes these effects can be protracted and severe.

Contraindications

Hypersensitivity to desvenlafaxine, venlafaxine hydrochloride or to any excipients in the DESFAX formulation. DESFAX must not be used in combination with monoamine oxidase inhibitors (MAOIs) or reversible MAOIs (such as moclobemide, linezolid and intravenous methylene blue), or within 14 days of discontinuing treatment with a MAOI. Similarly, DESFAX must be discontinued for at least 7 days before starting treatment with a MAOI.

PBS listing

DESFAX 50 mg modified release tablets are listed on the PBS with restriction type restricted and an ex-manufacturer price of A$6.45. DESFAX 100 mg modified release tablets are listed on the PBS with restriction type restricted and an ex-manufacturer price of A$7.92.

Regulatory history

DESFAX was first approved on 26 November 2014. ARTG registration includes ARTG 218075 for DESFAX desvenlafaxine 50 mg modified release tablets blister and ARTG 218061 for DESFAX desvenlafaxine 100 mg modified release tablets blister, both first listed 2014-11-26.