Usage
Finasteride + Tamsulosin is prescribed for the treatment of benign prostatic hyperplasia (BPH), specifically for men experiencing lower urinary tract symptoms (LUTS) associated with an enlarged prostate. It belongs to the pharmacological classifications of 5-alpha-reductase inhibitors (finasteride) and alpha-1 blockers (tamsulosin).
Finasteride works by inhibiting the 5-alpha-reductase enzyme, which converts testosterone to dihydrotestosterone (DHT). DHT is responsible for prostate growth; thus, reducing DHT levels helps shrink the prostate. Tamsulosin works by relaxing the smooth muscles in the prostate and bladder neck, improving urine flow.
Alternate Names
The combination of finasteride and tamsulosin itself does not have an international nonproprietary name (INN). However, the individual components do: finasteride and tamsulosin hydrochloride. It is sometimes referred to as a combination 5α-reductase inhibitor and α1-adrenergic receptor blocker.
Brand names may vary by region. Examples of brand names include: Tamplus.
How It Works
Pharmacodynamics: Finasteride reduces the size of the prostate gland by blocking the conversion of testosterone to DHT, leading to a decrease in prostate volume and improvement in BPH symptoms. Tamsulosin relaxes the smooth muscle in the prostate and bladder neck, facilitating urine flow without affecting prostate size.
Pharmacokinetics:
- Finasteride: Well absorbed orally, extensively metabolized in the liver by CYP3A4 enzymes, and primarily excreted in the feces.
- Tamsulosin: Almost completely absorbed orally, metabolized in the liver, and eliminated primarily through renal excretion.
Mode of Action:
- Finasteride: Inhibits Type II 5-alpha-reductase isoenzyme, selectively blocking DHT formation in the prostate.
- Tamsulosin: Selectively antagonizes postsynaptic alpha-1A-adrenergic receptors in the prostate smooth muscle, causing relaxation.
Elimination Pathways:
- Finasteride: Primarily fecal excretion; some urinary excretion.
- Tamsulosin: Primarily renal excretion.
Dosage
Standard Dosage
Adults:
One capsule containing finasteride 5 mg + tamsulosin hydrochloride (sustained-release) 0.4 mg once daily, administered 30 minutes after a meal. The dose may be titrated upwards to one capsule containing finasteride 5 mg + tamsulosin hydrochloride (sustained-release) 0.8 mg once daily if there is an inadequate response to the 0.4 mg dose of tamsulosin after 2-4 weeks.
Children:
Finasteride + Tamsulosin is not indicated for use in children.
Special Cases:
- Elderly Patients: Start with the standard adult dose, 30 min after the same meal each day.
- Patients with Renal Impairment: For mild to moderate renal impairment (CrCl greater than 10 mL/min), no dose adjustment is necessary. Caution should be exercised in patients with severe renal impairment, and no recommendation is made for dialysis patients.
- Patients with Hepatic Dysfunction: In patients with mild to moderate hepatic impairment, start with the standard adult dose. Use is contraindicated in patients with severe hepatic impairment.
- Patients with Comorbid Conditions: Exercise caution and individualize therapy based on the patient’s specific comorbid conditions.
Clinical Use Cases
Finasteride + Tamsulosin is not indicated for intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations.
Side Effects
Common Side Effects:
- Decreased libido
- Ejaculatory dysfunction
- Dizziness
- Headache
- Rhinitis
- Asthenia
Rare but Serious Side Effects:
- Angioedema
- Priapism
- Intraoperative floppy iris syndrome (IFIS)
- Gynecomastia
- Postural hypotension, syncope
Long-Term Effects:
The long-term effects of combined finasteride and tamsulosin are still being investigated.
Adverse Drug Reactions (ADR):
Any ADR suggestive of angioedema, priapism, or severe allergic reaction requires immediate discontinuation of the drug and appropriate medical intervention.
Contraindications
- Hypersensitivity to finasteride, tamsulosin, or any component of the formulation.
- Severe hepatic impairment.
- Use in women and children.
- History of orthostatic hypotension.
Drug Interactions
- CYP3A4 Inhibitors: May increase finasteride exposure.
- Alpha-blockers: Concomitant use may increase the risk of hypotension.
- PDE5 Inhibitors: May also increase the risk of hypotension.
Pregnancy and Breastfeeding
Finasteride is contraindicated in women who are or may become pregnant. Finasteride is present in semen; therefore, men being treated with finasteride should not father a child during treatment and for at least one month after discontinuation of therapy. It is unknown if tamsulosin is present in semen. Tamsulosin should not be used during breastfeeding.
Drug Profile Summary
- Mechanism of Action: Finasteride inhibits 5-alpha-reductase, reducing DHT levels and prostate volume. Tamsulosin is an alpha-1 blocker, relaxing smooth muscle in the prostate and bladder neck.
- Side Effects: Decreased libido, ejaculatory dysfunction, dizziness, headache, rhinitis. Serious side effects include angioedema and IFIS.
- Contraindications: Hypersensitivity, severe hepatic impairment, use in women and children.
- Drug Interactions: CYP3A4 inhibitors, alpha-blockers, PDE5 inhibitors.
- Pregnancy & Breastfeeding: Contraindicated in pregnancy and breastfeeding.
- Dosage: Finasteride 5 mg + Tamsulosin 0.4 mg or 0.8 mg once daily.
- Monitoring Parameters: Prostate-specific antigen (PSA) levels, LUTS assessment, blood pressure monitoring.
Popular Combinations
Finasteride + Tamsulosin is itself a popular combination used for managing BPH/LUTS. Occasionally other medications, such as antimuscarinics, might be added if there is an inadequate response.
Precautions
- General Precautions: Monitor for orthostatic hypotension, especially at initiation of therapy or with dose increases. Perform digital rectal examination and PSA testing before starting treatment and periodically thereafter.
- Specific Populations: Contraindicated in women and children. Use with caution in the elderly and patients with hepatic impairment.
- Lifestyle Considerations: Advise patients about potential side effects that may impact sexual function. Caution about dizziness or lightheadedness, especially when standing.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Finasteride + Tamsulosin?
A: The standard adult dosage is finasteride 5 mg + tamsulosin 0.4 mg once daily, 30 minutes after a meal. The tamsulosin component may be increased to 0.8 mg daily after 2-4 weeks if needed. It is not for use in children.
Q2: What are the common side effects?
A: Common side effects include decreased libido, ejaculatory dysfunction, dizziness, headache, and rhinitis.
Q3: What are the serious side effects?
A: Rare but serious side effects can include angioedema, intraoperative floppy iris syndrome, priapism, gynecomastia, postural hypotension, and syncope.
Q4: Can women take this medication?
A: No, finasteride + tamsulosin is contraindicated in women, especially during pregnancy.
Q5: What are the contraindications to using finasteride + tamsulosin?
A: Contraindications include hypersensitivity to either drug, severe hepatic impairment, and use in women and children.
Q6: Does this medication interact with other drugs?
A: Yes. Potential interactions can occur with CYP3A4 inhibitors, alpha-blockers, and PDE5 inhibitors, potentially leading to increased risk of hypotension.
Q7: Should the dosage be adjusted for renal or hepatic impairment?
A: Dosage adjustment is usually not necessary for mild to moderate renal or hepatic impairment. However, finasteride + tamsulosin is contraindicated in severe hepatic impairment. Use caution with severe renal impairment.
Q8: How does this combination improve BPH symptoms?
A: Finasteride shrinks the prostate, while tamsulosin relaxes the prostate and bladder neck muscles, leading to improved urine flow and reduced LUTS.
Q9: What should patients be monitored for?
A: Patients should be monitored for changes in blood pressure, orthostatic hypotension, LUTS, PSA levels, and the development of any adverse reactions.
