Products
Paroxetine is commercially available as film-coated tablets and as a suspension (Deroxat, generic). It has been approved in many countries since 1993. Paroxetine is also marketed as Seroxat and Paxil in some countries. Slow-release paroxetine (CR) is not currently available in many countries.
Structure and properties
Paroxetine (C19H20FNO3, Mr = 329.4 g/mol) is present in drugs as paroxetine hydrochloride hemihydrate (paroxetine – HCl – 1/2 H2O), a white crystalline powder that is sparingly soluble in water. In generic drugs, it is also sometimes present as anhydrous paroxetine hydrochloride or paroxetine mesilate. Paroxetine is a benzodioxole and phenylpiperidine derivative.
Effects
Paroxetine (ATC N06AB05) has antidepressant properties. The effects are attributed to inhibition of the reuptake of serotonin into the presynapse of neurons. Inhibition of the serotonin transporter SERT increases serotonin concentration in the synaptic cleft.
Indications
For the treatment of depression, panic and anxiety disorders, obsessive-compulsive disorder, and posttraumatic stress disorder. In the United States, low-dose paroxetine is also approved for the treatment of flushing associated with menopause.
Dosage
According to the Specialized Information. Paroxetine is usually taken once daily in the morning with breakfast. The recommended dose is 20 mg for most indications but may be increased depending on the indication. Discontinuation must be gradual to avoid withdrawal symptoms.
Contraindications
- Hypersensitivity
- Children and adolescents
- Concurrent treatment with an MAO inhibitor, thioridazine, or pimozide.
Full details of precautions and interactions can be found in the drug label.
Interactions
Paroxetine is partially metabolized by CYP2D6 and inhibits the isoenzyme. Drug-drug interactions are possible with numerous other agents.
Adverse effects
The most common potential adverse effects include nausea, drowsiness, insomnia, and sexual dysfunction such as ejaculatory dysfunction and decreased libido. Other common side effects include agitation, dreaming, weakness, weight gain, yawning, dizziness, tremor, headache, sweating, constipation, diarrhea, vomiting, dry mouth, and loss of appetite. Weaning symptoms may occur upon discontinuation.
