Fonksera or Fonksera (Vortioxetine) 20 MG Tablets

Vortioxetine is used in the treatment of major depressive disorder in children. It is an SSRI (selective serotonin reuptake inhibitor) and serotonin receptor modulator that helps restore the balance of serotonin in the brain. Low serotonin levels can cause disorder, anxiety, mania, and other mental health problems.

Vortioxetine works to block serotonin reuptake. It differs from other SSRIs in that it directly modulates various serotonin receptors.

Dosage Follow the instructions on the prescription label. Use the medication exactly as directed. Take vortioxetine with or without food. If a dose is completely forgotten, apply a double dose the next day. Do not change dosage according to a healthcare professional, even if symptoms seem to disappear.

Vortioxetine (Fonksera) is an antidepressant with primarily serotonergic activity, which makes it related to selective serotonin reuptake inhibitors (SSRIs). The main adverse effects are: gastrointestinal disorders, abnormal dreams, dizziness, and itching. There have been reports of angioedema and urticaria, and bleeding (especially at the level of the skin and mucous membranes, e.g., the gastrointestinal system), and of serotonin syndrome in association with other serotonergic drugs.

Although well described with antidepressants, the Summary of Product Characteristics (SPC) of the specialties based on Fonksera did not mention the risk of sexual disorders (except at daily doses of 20 mg, the maximum dose) or withdrawal symptoms when stopping until recently. After reassessment of the available data by the European Pharmacovigilance Committee PRAC, the SPC and leaflet of the specialties based on vortioxetine have recently been updated, mentioning the risk of sexual disorders, including at doses lower than 20 mg, and the risk of withdrawal symptoms.

Sexual disorders

• As part of post-marketing surveillance, sexual disorders have been reported during treatment with vortioxetine (no frequency reported). This involved patients treated with vortioxetine at a dose of 20 mg per day as well as lower doses (5-10 mg per day). The most reported sexual disorders are: decreased libido, erectile dysfunction, and sexual disorders (without further specification). This is consistent with the known sexual side effects of SSRIs.

Withdrawal Symptoms

• As part of post-marketing surveillance, withdrawal symptoms have been reported after discontinuation of vortioxetine. The symptoms are very similar to those of SSRIs. These include dizziness, headache, sensory symptoms (including paresthesias and sensation of electric shocks), sleep disorders, nausea, vomiting, anxiety, irritability, agitation, fatigue, and tremors. These symptoms can occur within a week after stopping vortioxetine. Withdrawal symptoms occurred in 3% of the patients. Given the limited number of patients in the study and the analysis of retrospectively collected data, additional studies are needed to better specify and quantify this risk.
• A retrospective analysis of medical records from 263 patients (> 18 years) who had stopped vortioxetine evaluated the risk of withdrawal symptoms.1 The analysis was published in 2021. Withdrawal symptoms were observed in 3% (n=8) of the patients who had stopped vortioxetine (gradually in 5 patients or abruptly in 3 patients) after a treatment duration between 71 and 375 days (median: 272 days). The median duration until the onset of symptoms after stopping was 3 days (range: 1.25-4.75 days). In 5 patients, the symptoms disappeared spontaneously within 3 to 10 days (median: 7 days). The other 3 patients restarted vortioxetine, after which the symptoms quickly disappeared. The most common withdrawal symptoms were emotional instability, irritability, sudden deterioration of mood, nervousness, and agitation. Given the limited number of patients in the study and the analysis of retrospectively collected data, additional studies are needed to better specify and quantify this risk.
• To prevent withdrawal symptoms, a gradual dose reduction may be appropriate. The multidisciplinary document “Tapering off other antidepressants” recommends that for vortioxetine, a gradual tapering is desirable if the patient prefers it or if there are risk factors present. We provide some details and a concrete tapering schedule in the update of our article “Handles for tapering off antidepressants” which will appear soon.