Before treatment is initiated, see Section 4. The clinical relevance of the effect on midazolam is likely to be small in most patients. A dose response relationship for syncope is suggested based on subject incidence across all studies. No overall differences were seen in efficacy or safety between poor and extensive metabolisers. Dapoxetine may give rise to a similar increase in the plasma concentrations of other drugs metabolized by CYP2D6. Effects of dapoxetine hydrochloride on co-administered medicinal products. In the two multidose phase 3 studies C and C where the CYP2D6 metaboliser status was identified, a total of poor metabolisers and extensive metabolisers were enrolled and treated with Priligy.Priligy contains the active ingredient dapoxetine, which is a selective serotonin reuptake inhibitor (SSRI). It works by boosting the levels of serotonin in the body, causing a delayed reaction in the areas of the brain that cause ejaculation. This means it . Dizziness, Headache. Somnolence, Disturbance in attention, Tremor, Paraesthesia. Syncope, Syncope vasovagal, Dizziness postural, Akathisia, Dysgeusia, Hypersomnia, Lethargy, Sedation, Depressed level of consciousness. Dizziness exertional, Sudden onset of sleep. Eye disorders. Priligy is a prescription-only medicine to help treat symptoms of premature ejaculation (PE), in men aged between 18 and It contains dapoxetine, a ‘short-acting selective serotonin reuptake inhibitor’ (SSRI). Priligy was the first oral treatment for PE to be licensed in the UK.