Paroxetine is a selective serotonin reuptake inhibitor (SSRI) widely prescribed for the management of major depressive disorder, various anxiety disorders, and other related psychiatric conditions. As a potent and well-studied antidepressant, it functions by increasing serotonin levels in the brain, which helps restore chemical balance and improve mood, sleep, appetite, and energy levels. Its efficacy, tolerability profile, and established history in clinical practice make it a cornerstone in psychopharmacological treatment.

Features

• Active ingredient: Paroxetine hydrochloride
• Available in tablet and oral suspension formulations
• Standard strengths: 10 mg, 20 mg, 30 mg, 40 mg
• Extended-release formulation available for once-daily dosing
• FDA-approved for multiple psychiatric indications
• Bioavailability approximately 50–100%, unaffected by food
• Half-life of approximately 21 hours (24 hours for controlled-release)

Benefits

• Effectively reduces symptoms of depression, including low mood and loss of interest
• Alleviates anxiety, panic attacks, and obsessive-compulsive thoughts
• Improves overall quality of life and social functioning
• Helps restore normal sleep patterns and appetite
• Reduces the frequency and intensity of hot flashes in menopausal women (off-label use)
• Long-term maintenance therapy can prevent relapse of depressive episodes

Common use

Paroxetine is primarily indicated for the treatment of major depressive disorder (MDD), generalized anxiety disorder (GAD), panic disorder, social anxiety disorder, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD). It is also used off-label for premenstrual dysphoric disorder (PMDD), vasomotor symptoms of menopause, and certain chronic pain syndromes. Treatment duration varies based on individual response and the specific condition being managed, often involving an acute phase followed by maintenance therapy.

Dosage and direction

Dosage must be individualized based on the patient’s condition, response, and tolerability. For depression and anxiety disorders, the typical starting dose is 20 mg once daily, preferably in the morning. Dose adjustments may be made in increments of 10 mg at weekly intervals, with a maximum recommended dose of 50–60 mg per day for most adults. For elderly patients or those with hepatic impairment, a lower starting dose (e.g., 10 mg) is advised. Paroxetine should be taken with or without food, at the same time each day. Tablets should be swallowed whole and not crushed or chewed. Abrupt discontinuation should be avoided; gradual tapering is recommended under medical supervision.

Precautions

Patients should be monitored closely for clinical worsening, suicidality, or unusual changes in behavior, especially during the initial few months of therapy or after dose changes. Paroxetine may impair judgment, thinking, or motor skills; caution is advised when driving or operating machinery. Use with caution in patients with a history of mania, seizures, or angle-closure glaucoma. Regular monitoring of electrolytes, liver function, and complete blood count may be warranted during long-term therapy. Pregnancy and breastfeeding require careful risk-benefit assessment.

Contraindications

Paroxetine is contraindicated in patients with known hypersensitivity to paroxetine or any component of the formulation. Concomitant use with monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing MAOI therapy is contraindicated due to the risk of serotonin syndrome. It is also contraindicated in patients taking pimozide or thioridazine. Use is not recommended in individuals with uncontrolled narrow-angle glaucoma.

Possible side effect

Common side effects include nausea, somnolence, asthenia, dizziness, insomnia, sweating, and sexual dysfunction. Less frequently, dry mouth, constipation, diarrhea, blurred vision, weight changes, and tremor may occur. Serious but rare adverse effects include serotonin syndrome, hyponatremia, abnormal bleeding, angle-closure glaucoma, and seizures. Some patients may experience withdrawal symptoms upon discontinuation. Most side effects are dose-dependent and may diminish over time.

Drug interaction

Paroxetine is a potent inhibitor of CYP2D6 and may interact with drugs metabolized by this enzyme, such as tricyclic antidepressants, antipsychotics, beta-blockers, and certain antiarrhythmics. Concomitant use with serotonergic drugs (e.g., other SSRIs, SNRIs, triptans, tramadol) increases the risk of serotonin syndrome. It may enhance the anticoagulant effect of warfarin. Use with NSAIDs or aspirin may increase bleeding risk. Caution is advised with drugs that prolong QT interval.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is almost time for the next scheduled dose. In that case, the missed dose should be skipped, and the regular dosing schedule resumed. Doubling the dose to make up for a missed one is not recommended.

Overdose

Symptoms of overdose may include nausea, vomiting, drowsiness, sinus tachycardia, dilated pupils, and agitation. Severe overdose can lead to serotonin syndrome, seizures, coma, or ECG changes. There is no specific antidote; management involves supportive care, gastric lavage if presented early, and activated charcoal. Monitoring of vital signs and ECG is essential. Contact a poison control center or seek emergency medical attention immediately.

Storage

Store at room temperature (20–25°C or 68–77°F), in a tightly closed container, away from light, moisture, and heat. Keep out of reach of children and pets. Do not use beyond the expiration date printed on the packaging. Oral suspension should not be frozen.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Paroxetine is a prescription medication and should be used only under the supervision of a qualified healthcare professional. Individual response to treatment may vary. Always follow your healthcare provider’s instructions and report any side effects or concerns promptly.

Reviews

Clinical studies and meta-analyses consistently demonstrate paroxetine’s efficacy in reducing symptoms of depression and anxiety, with response rates often exceeding 60% in compliant patients. Many users report significant improvement in mood, reduced anxiety, and better daily functioning after several weeks of treatment. Some note initial side effects such as nausea or drowsiness, which often subside. Long-term users appreciate its preventive benefits against relapse. Critical reviews sometimes highlight sexual side effects or withdrawal challenges, emphasizing the need for careful management and patient education.