Overview
Paroxetine is a selective serotonin reuptake inhibitor (SSRI) antidepressant used to treat major depressive disorder and various anxiety disorders. It works by increasing serotonin levels in the brain, which helps regulate mood and anxiety. It carries warnings for suicidal thoughts, serotonin syndrome, and discontinuation syndrome.
Mechanism of Action
Paroxetine is a potent and highly selective inhibitor of neuronal serotonin reuptake (SSRI), blocking serotonin uptake into platelets and neurons with minimal effects on norepinephrine and dopamine reuptake.
Indications
- Major depressive disorder (MDD)
- Obsessive compulsive disorder (OCD)
- Panic disorder (PD)
- Social anxiety disorder (SAD)
- Generalized anxiety disorder (GAD)
- Posttraumatic stress disorder (PTSD)
Common Doses
- 10 mg
- 20 mg
- 30 mg
- 40 mg
Dosage
Typically initiated at 20 mg once daily, with dosage adjustments based on indication and patient response. Maximum recommended dose is 60 mg daily. Should be tapered gradually when discontinuing to avoid withdrawal symptoms.
Contraindications
- Concomitant use with MAOIs or within 14 days of stopping MAOIs
- Concomitant use with thioridazine
- Concomitant use with pimozide
- Known hypersensitivity to paroxetine or inactive ingredients
Side Effects
- Nausea, somnolence, dizziness, insomnia
- Sexual dysfunction
- Weight changes
- Sweating
- Dry mouth
- Constipation
- Fatigue
- Headache
- Withdrawal symptoms upon discontinuation
Interactions
- MAOIs (serotonin syndrome risk)
- Other serotonergic drugs (SSRIs, SNRIs, triptans, opioids, lithium)
- Antiplatelets/anticoagulants (increased bleeding risk)
- CYP2D6 substrates (increased exposure)
- Tamoxifen (reduced efficacy)
- Pimozide/thioridazine (QT prolongation)
Counseling Points
- Take consistently at same time each day
- Do not stop abruptly due to withdrawal risk
- Report any worsening depression or suicidal thoughts
- Avoid alcohol consumption
- Use caution with activities requiring alertness
- Report unusual bleeding or bruising
- Discuss sexual side effects with provider