Usage
- Dapoxetine + Sildenafil is prescribed for the treatment of premature ejaculation (PE) in men who also have erectile dysfunction (ED).
- Pharmacological Classification: Dapoxetine is a short-acting selective serotonin reuptake inhibitor (SSRI), and Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor.
- Mechanism of Action: Dapoxetine increases serotonin levels in the brain, which delays ejaculation. Sildenafil enhances blood flow to the penis by inhibiting PDE5, facilitating erection.
Alternate Names
- While the combination itself doesn’t have a distinct international nonproprietary name (INN), its components do: dapoxetine hydrochloride and sildenafil citrate.
- Brand Names: The combination is available under various brand names globally, which can vary by region. Some examples include Super Welgra, Duralong, and Westoxetin-S.
How It Works
- Pharmacodynamics: Dapoxetine inhibits the serotonin transporter, increasing serotonin’s effect in the synapse, which is thought to delay ejaculation. Sildenafil inhibits PDE5, preventing the degradation of cyclic guanosine monophosphate (cGMP) in the corpus cavernosum of the penis. This leads to smooth muscle relaxation, increased blood flow, and erection.
- Pharmacokinetics: Dapoxetine is rapidly absorbed and metabolized primarily by the liver (CYP3A4 and CYP2D6 enzymes), with a short half-life. Sildenafil is also metabolized by the liver (CYP3A4) and has a half-life of approximately 4 hours. Both drugs are primarily excreted via renal and fecal pathways.
- Mode of Action: Dapoxetine’s action is related to serotonin reuptake inhibition at the presynaptic neuron. Sildenafil acts by selectively inhibiting PDE5 in the corpus cavernosum, leading to vasodilation.
- Receptor binding, enzyme inhibition, or neurotransmitter modulation: Dapoxetine inhibits the serotonin transporter. Sildenafil inhibits PDE5.
- Elimination pathways: Both dapoxetine and sildenafil are metabolized in the liver and excreted via renal and fecal routes.
Dosage
Standard Dosage
Adults:
- The typical dose is one tablet containing 30 mg dapoxetine and 50 mg sildenafil, taken orally 1 to 3 hours before anticipated sexual activity. The dose may be increased to 60 mg dapoxetine and 100 mg sildenafil if needed and tolerated. The maximum frequency is once per day.
Children:
- Dapoxetine + Sildenafil is not indicated for use in children.
Special Cases:
- Elderly Patients: Caution is advised due to potential age-related changes in drug clearance. Dose adjustments may be needed.
- Patients with Renal Impairment: Dose adjustment may be needed in patients with moderate to severe renal impairment.
- Patients with Hepatic Dysfunction: Dose adjustment is needed in patients with moderate to severe hepatic impairment.
- Patients with Comorbid Conditions: Caution is advised in patients with cardiovascular disease, hypotension, and other conditions. Close monitoring is recommended.
Clinical Use Cases
Dapoxetine + Sildenafil is specifically indicated for PE and ED, and its use is limited to this context. It’s not used in settings like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations.
Dosage Adjustments
Dosage modifications may be necessary based on individual patient response, tolerability, and the presence of renal or hepatic impairment.
Side Effects
Common Side Effects:
- Headache
- Dizziness
- Nausea
- Diarrhea
- Insomnia
- Fatigue
- Flushing
Rare but Serious Side Effects:
- Syncope
- Seizures
- Allergic reactions (e.g., skin rash, itching, swelling)
- Priapism (prolonged erection lasting more than 4 hours)
- Mania or hypomania
Long-Term Effects:
Limited data are available on long-term effects.
Adverse Drug Reactions (ADR):
Serious ADRs are rare but require immediate medical attention. These include severe hypotension, priapism, and allergic reactions.
Contraindications
- Hypersensitivity to dapoxetine, sildenafil, or any component of the formulation
- Severe cardiovascular disease
- History of stroke or myocardial infarction
- Uncontrolled hypertension or hypotension
- Severe hepatic or renal impairment
- Concomitant use of nitrates or other PDE5 inhibitors
Drug Interactions
- Nitrates (contraindicated)
- MAOIs (contraindicated)
- Certain antidepressants (e.g., SSRIs, SNRIs)
- CYP3A4 inhibitors (e.g., ketoconazole, erythromycin)
- CYP2D6 inhibitors (e.g., fluoxetine, paroxetine)
- Alcohol (should be avoided or consumed with caution)
- Grapefruit juice (should be avoided)
Pregnancy and Breastfeeding
- Dapoxetine + Sildenafil is not indicated for use in women, including pregnant and breastfeeding women.
Drug Profile Summary
- Mechanism of Action: Dapoxetine: SSRI; Sildenafil: PDE5 inhibitor.
- Side Effects: Headache, dizziness, nausea, flushing. Rare: syncope, seizures, priapism, allergic reactions.
- Contraindications: Hypersensitivity, severe cardiovascular disease, nitrates, MAOIs.
- Drug Interactions: Nitrates, MAOIs, certain antidepressants, CYP3A4/2D6 inhibitors, alcohol.
- Pregnancy & Breastfeeding: Not indicated for use in women.
- Dosage: 30 mg dapoxetine/50 mg sildenafil, up to 60 mg/100 mg if needed, once daily.
- Monitoring Parameters: Blood pressure, heart rate.
Popular Combinations
Dapoxetine + Sildenafil is itself a combination product. It is not typically combined with other medications for the treatment of PE and ED.
Precautions
- Careful patient selection is crucial, including assessment of cardiovascular risk factors.
- Monitor for orthostatic hypotension, especially with initial dosing.
- Patients should be advised not to drive or operate heavy machinery until the drug’s effects are known.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Dapoxetine + Sildenafil?
A: The typical starting dose is 30 mg dapoxetine/50 mg sildenafil, taken 1-3 hours before sexual activity. The dose may be increased to 60 mg/100 mg if needed and tolerated. The maximum frequency is once per day.
Q2: Can this combination be used in patients with only premature ejaculation, without erectile dysfunction?
A: While dapoxetine alone can be used for PE, the combination is indicated for patients experiencing both PE and ED.
Q3: What are the most common side effects patients should be aware of?
A: Headache, dizziness, nausea, and flushing are the most commonly reported side effects.
Q4: Are there any serious drug interactions I should be aware of?
A: Concomitant use of nitrates and MAOIs is contraindicated. Caution is advised with certain antidepressants and CYP3A4/2D6 inhibitors.
Q5: Can patients consume alcohol while taking this medication?
A: Alcohol consumption should be avoided or limited, as it can exacerbate certain side effects like dizziness and hypotension.
Q6: What should a patient do if they experience a prolonged erection (priapism)?
A: Priapism is a rare but serious side effect. Patients experiencing an erection lasting longer than 4 hours should seek immediate medical attention.
Q7: Is Dapoxetine + Sildenafil safe for patients with heart conditions?
A: It’s contraindicated in patients with severe cardiovascular disease, recent history of myocardial infarction or stroke, and uncontrolled hypertension or hypotension. Patients with any heart condition should discuss its use with their cardiologist.
Q8: Can this combination be used daily?
A: No, the maximum recommended frequency is once per day.
Q9: How long does the effect of Dapoxetine + Sildenafil last?
A: Dapoxetine has a short half-life, providing a relatively rapid onset and offset of action for PE. Sildenafil’s effects on ED typically last for approximately 4 hours.
Q10: Is this medication addictive?
A: Dapoxetine + Sildenafil does not typically lead to physical dependence or addiction.
