Usage
- Dapoxetine is prescribed for the treatment of premature ejaculation (PE) in adult men aged 18-64 years. Premature ejaculation is defined as ejaculation occurring sooner than desired, with minimal sexual stimulation, causing distress and impacting interpersonal relationships.
- Pharmacological Classification: Selective Serotonin Reuptake Inhibitor (SSRI)
- Mechanism of Action: Dapoxetine increases the level of serotonin in the nervous system. Serotonin plays a role in ejaculatory control, and by increasing its action at the post synaptic cleft, dapoxetine delays ejaculation.
Alternate Names
- International/Regional Variations: Dapoxetine hydrochloride
- Brand Names: Priligy, Longride 30
How It Works
- Pharmacodynamics: Dapoxetine primarily exerts its effect by inhibiting the serotonin transporter, thus increasing serotonin’s action at the postsynaptic cleft. This leads to delayed ejaculation.
- Pharmacokinetics: Dapoxetine is rapidly absorbed and eliminated, reaching peak plasma concentrations approximately 1-2 hours after oral administration. It is extensively metabolized in the liver primarily by CYP2D6, CYP3A4 and FMO1, with dapoxetine-N-oxide being the major inactive metabolite. Active metabolites include desmethyldapoxetine (equipotent to dapoxetine) and didesmethyldapoxetine. Elimination is primarily through renal excretion.
- Mode of Action: Dapoxetine inhibits the serotonin transporter, leading to increased serotonin levels in the synaptic cleft. This increased serotonergic neurotransmission modulates the ejaculatory reflex, delaying ejaculation.
- Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: Serotonin transporter inhibition.
- Elimination Pathways: Primarily renal excretion, with hepatic metabolism by CYP2D6, CYP3A4 and flavin monooxygenase (FMO1).
Dosage
Standard Dosage
Adults:
- Initial dose: 30 mg taken orally 1-3 hours before anticipated sexual activity.
- Maximum dose: 60 mg once every 24 hours. The higher dose (60mg) should only be considered if the 30mg dose is insufficient, provided the patient has not experienced moderate or severe adverse reactions or symptoms suggesting syncope.
- Administration: As needed, not for continuous daily use.
Children:
- Dapoxetine is not recommended for use in individuals below 18 years of age.
Special Cases:
- Elderly Patients (65 years and over): Not recommended due to limited safety and efficacy data.
- Patients with Renal Impairment: Caution advised in mild or moderate impairment. Not recommended in severe renal impairment (creatinine clearance < 30 mL/min).
- Patients with Hepatic Dysfunction: Contraindicated in moderate to severe hepatic impairment (Child-Pugh class B or C).
- Patients with Comorbid Conditions: Use with caution in patients with cardiovascular disease, epilepsy, history of mania or depression, glaucoma or bleeding disorders.
Clinical Use Cases
Dapoxetine is specifically indicated for on-demand treatment of premature ejaculation. It is not intended for use in other clinical settings such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations.
Dosage Adjustments
- Concomitant use of potent CYP2D6 inhibitors: Use caution if increasing dose to 60 mg. With potent CYP3A4 inhibitors, the maximum dose is 30 mg.
- Concomitant use of moderate CYP3A4 inhibitors: Maximum dose is 30 mg.
- Patients with renal or hepatic dysfunction: See above.
Side Effects
Common Side Effects:
- Dizziness, headache, nausea, diarrhea, dry mouth, insomnia.
Rare but Serious Side Effects:
- Syncope, seizures, mania, hypomania, suicidal ideation, serotonin syndrome.
Long-Term Effects:
Limited data is available on the long-term effects of dapoxetine. Regular review of treatment efficacy and benefit-risk balance is recommended, especially beyond 24 weeks of use.
Adverse Drug Reactions (ADR):
- Syncope, seizures, serotonin syndrome, mania.
Contraindications
- Hypersensitivity to dapoxetine.
- Moderate to severe hepatic impairment.
- Significant cardiovascular disease (e.g., heart failure, recent myocardial infarction or stroke).
- Concomitant use of MAOIs, thioridazine, or other SSRIs/SNRIs/TCAs.
Drug Interactions
- CYP450 Interactions: Dapoxetine is metabolized by CYP2D6 and CYP3A4. Concomitant use of potent CYP2D6 or CYP3A4 inhibitors can significantly increase dapoxetine serum concentrations, potentially leading to adverse events.
- Medications: MAOIs, thioridazine, other SSRIs/SNRIs/TCAs, potent CYP3A4 inhibitors (e.g., ketoconazole, ritonavir), moderate CYP3A4 inhibitors (e.g., erythromycin, fluconazole), anticoagulants, antiplatelet agents.
- OTC Drugs/Supplements: St. John’s Wort.
- Food/Lifestyle: Alcohol (increases risk of adverse effects), grapefruit juice (increases dapoxetine levels).
Pregnancy and Breastfeeding
- Dapoxetine is not indicated for use in women.
- No data available on fetal risk or excretion in breast milk.
Drug Profile Summary
- Mechanism of Action: Serotonin transporter inhibitor.
- Side Effects: Dizziness, headache, nausea, syncope (rare).
- Contraindications: Hepatic impairment, cardiovascular disease, MAOI use.
- Drug Interactions: MAOIs, SSRIs/SNRIs/TCAs, CYP3A4 inhibitors, alcohol.
- Pregnancy & Breastfeeding: Not for use in women.
- Dosage: 30-60 mg as needed, max once every 24 hours.
- Monitoring Parameters: Blood pressure, heart rate, mental status.
Popular Combinations
Dapoxetine is sometimes used in combination with phosphodiesterase-5 inhibitors (PDE5 inhibitors) like sildenafil to treat both premature ejaculation and erectile dysfunction. However, some sources indicate that dapoxetine should not be used with PDE5 inhibitors.
Precautions
- General Precautions: Assess for history of cardiovascular disease, hepatic/renal impairment, psychiatric disorders.
- Specific Populations: Not for use in women or individuals under 18 years. Caution in elderly patients.
- Lifestyle Considerations: Avoid alcohol and grapefruit juice. Caution when driving or operating machinery.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Dapoxetine?
A: The initial dose is 30 mg taken 1-3 hours before sexual activity, with a maximum dose of 60 mg once every 24 hours.
Q2: Can Dapoxetine be taken daily?
A: No, dapoxetine is designed for on-demand use before anticipated sexual activity, not for continuous daily use.
Q3: Who should not take Dapoxetine?
A: Patients with moderate to severe hepatic impairment, significant heart disease, or those taking MAOIs or certain other medications should not take dapoxetine.
Q4: What are the common side effects of Dapoxetine?
A: Dizziness, headache, nausea, diarrhea, and dry mouth are common side effects.
Q5: Can I drink alcohol while taking Dapoxetine?
A: Alcohol can increase the risk of side effects like dizziness and drowsiness and should be avoided.
Q6: What if I miss a dose of Dapoxetine?
A: As dapoxetine is taken as needed, a missed dose is not typically a concern. Simply take it before the next anticipated sexual activity.
Q7: Can Dapoxetine be used in elderly patients?
A: Dapoxetine is not recommended in patients over 65 years old due to limited data.
Q8: Is Dapoxetine safe to use with other medications for erectile dysfunction?
A: Some sources suggest avoiding combined use, while others indicate potential combined usage. Consult with a healthcare professional before combining dapoxetine with other medications for erectile dysfunction.
Q9: What should I do if I experience dizziness while taking Dapoxetine?
A: Avoid driving or operating machinery. Stand up slowly from a sitting or lying position. If dizziness is severe or persistent, consult your doctor.
