Avodart

Avodart (dutasteride) is a prescription medication specifically formulated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate. As a potent 5-alpha-reductase inhibitor, it works by targeting the hormonal pathway responsible for prostate growth, leading to a significant reduction in prostate volume. This action alleviates urinary obstructive symptoms, improves urinary flow, and reduces the risk of acute urinary retention and the need for BPH-related surgery. Its targeted mechanism offers a well-tolerated, long-term management strategy for this common condition affecting aging males.

Features

• Active Ingredient: Dutasteride 0.5 mg
• Pharmacological Class: Dual 5-alpha-reductase inhibitor (Type 1 and Type 2)
• Formulation: Soft gelatin capsules for oral administration
• Bioavailability: Approximately 60% (range 40% to 94%)
• Half-life: Approximately 5 weeks at steady state
• Time to Peak Plasma Concentration: 2 to 3 hours post-dose
• Steady-State Concentration: Achieved after 4 to 6 months of daily dosing
• Excretion: Primarily fecal (as metabolites)

Benefits

• Significantly reduces prostate volume, leading to decreased urethral obstruction.
• Improves urinary flow rate and reduces bothersome lower urinary tract symptoms (LUTS).
• Lowers the incidence of acute urinary retention, a painful complication of BPH.
• Reduces the long-term risk of requiring BPH-related surgical intervention.
• Provides a convenient, once-daily dosing regimen for consistent therapeutic effect.
• Offers a targeted therapeutic approach with a well-established long-term safety profile.

Common use

Avodart is indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate. It is used to improve symptoms, reduce the risk of acute urinary retention, and decrease the need for BPH-related surgery. Treatment is intended for long-term management rather than immediate symptom relief. It is not indicated for use in women or children. Avodart is also used in combination with the alpha-blocker tamsulosin (marketed as Jalyn) for an enhanced therapeutic effect in appropriate patients.

Dosage and direction

The recommended dosage of Avodart is one 0.5 mg capsule taken orally once daily. The capsule should be swallowed whole and may be taken with or without food, as food does not affect its absorption. Patients should be advised to adhere to a consistent dosing schedule. A treatment period of at least 6 months is usually necessary to assess whether an individual will respond to therapy, as symptom improvement and reduction in prostate size are gradual. Dutasteride has a long half-life; persistence of drug effect should be considered even after discontinuation. Dosage adjustment is not necessary for elderly patients or those with renal impairment. Use in patients with hepatic impairment has not been fully studied and should be approached with caution.

Precautions

Avodart is contraindicated in women who are or may become pregnant and in children due to the risk of causing abnormalities of the external genitalia in a male fetus. Women who are pregnant or could become pregnant must not handle leaking capsules, as dutasteride can be absorbed through the skin. Patients should be informed that Avodart reduces serum prostate-specific antigen (PSA) levels by approximately 50% after 6 months of treatment. PSA values for monitoring prostate cancer must, therefore, be doubled for comparison to pre-treatment levels to maintain their utility in cancer screening. A digital rectal exam (DRE) and other evaluation for prostate cancer should be performed on patients with BPH prior to initiating therapy and periodically thereafter. Patients should be advised that they may experience a decrease in ejaculate volume but that this does not appear to interfere with normal sexual function. As with any 5-alpha-reductase inhibitor, a small increased risk of high-grade prostate cancer has been observed. Patients should report any breast changes (lumps, pain, or nipple discharge) to their physician promptly.

Contraindications

Avodart is contraindicated in the following populations:

• Women who are pregnant or may become pregnant.
• Pediatric patients.
• Patients with a known hypersensitivity to dutasteride, other 5-alpha-reductase inhibitors, or any component of the formulation.

Possible side effect

The majority of adverse reactions associated with Avodart are sexual in nature and are generally mild to moderate. The most commonly reported side effects include:

• Decreased libido (3% to 5%)
• Erectile dysfunction (4% to 7%)
• Ejaculation disorders (1% to 4%, primarily decreased ejaculate volume)
• Gynecomastia (including breast enlargement and breast tenderness) (1% to 2%)

These events often decrease with continued treatment. Other less common side effects may include dizziness, and in rare instances, allergic reactions such as rash, pruritus, urticaria, and localized and generalized edema. As noted in the PRECAUTIONS section, patients should be monitored for breast changes.

Drug interaction

Formal drug interaction studies have been conducted with Avodart. Dutasteride is extensively metabolized by the CYP3A4 enzyme system. Concomitant administration of Avodart with potent CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, verapamil, diltiazem, cimetidine, ciprofloxacin) may increase the concentration of dutasteride. However, due to its wide therapeutic index, no dosage adjustment is recommended. No clinically significant interactions were observed with tamsulosin, terazosin, warfarin, digoxin, or cholestyramine. The combination of dutasteride and an alpha-blocker (e.g., tamsulosin in Jalyn) is a recognized therapeutic regimen, and no new interactions are attributed to the combination beyond those known for the individual drugs.

Missed dose

If a dose of Avodart is missed, the patient should take it as soon as he remembers. However, if it is almost time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule resumed. Patients should not take a double dose to make up for a missed one. Due to the long half-life of dutasteride, a single missed dose is not expected to have a significant impact on the overall therapeutic effect.

Overdose

In clinical studies, doses of Avodart up to 40 mg/day (80 times the therapeutic dose) for 7 days have been administered without significant adverse effects. In the event of a suspected overdose, supportive and symptomatic treatment is recommended. Since dutasteride is highly protein-bound, dialysis is unlikely to be of benefit. There is no specific antidote for dutasteride overdose.

Storage

Avodart capsules should be stored at room temperature, between 20°C to 25°C (68°F to 77°F), with excursions permitted between 15°C and 30°C (59°F and 86°F). The capsules must be kept in their original blister pack to protect them from light and moisture until the moment they are taken. Keep this medication out of the reach of children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here. The information provided is based on the manufacturer’s prescribing information but may not be all-inclusive.

Reviews

Clinical trials and post-marketing surveillance demonstrate that Avodart is an effective and generally well-tolerated treatment for the management of BPH. In large-scale studies such as the CombAT (Combination of Avodart and Tamsulosin) and ARIA (Avodart Reduce Incidence of Acute Urinary Retention) trials, dutasteride consistently showed a significant reduction in prostate volume (median reduction of ~25%), a 57% reduction in the relative risk of acute urinary retention, and a 48% reduction in the relative risk of BPH-related surgery compared to placebo over 4 years. Patient-reported outcomes indicate meaningful improvements in symptom scores (IPSS) and quality of life. The long half-life is noted by clinicians as both a benefit for consistent effect and a consideration for the slow onset of action and persistence of effect after discontinuation. The sexual side effects are the most commonly cited reason for discontinuation in a small percentage of patients, though many find these effects manageable or diminishing over time.