What is the recommended dose of Intrarosa (prasterone) for a postmenopausal woman with vaginal dryness and pain during intercourse?

Intrarosa (Prasterone) Dosing for Postmenopausal Vaginal Atrophy

The recommended dose of Intrarosa (prasterone) is 6.5 mg administered intravaginally once daily at bedtime for the treatment of moderate to severe dyspareunia and vaginal dryness due to vulvovaginal atrophy in postmenopausal women. 1, 2, 3

Standard Dosing Regimen

• Administer 6.5 mg (0.50%) prasterone intravaginally once daily, preferably at bedtime, using the provided applicator 1, 2, 4
• Treatment duration has been studied for up to 52 weeks with maintained efficacy and safety 2
• Peak serum concentrations occur at 1.5 to 2 hours after administration, with no accumulation during daily dosing 1

Clinical Efficacy Data

• Prasterone 6.5 mg daily significantly reduces dyspareunia severity scores by 1.27 to 1.63 units from baseline, with improvements over placebo ranging from 0.35 to 1.21 units 4
• Vaginal dryness severity decreases by 1.44 to 1.58 units from baseline, with improvements over placebo of 0.30 to 0.43 units 4
• Improvements in vaginal pH, parabasal cells, and superficial cells are evident within 12 weeks and maintained through 52 weeks of treatment 2, 3

Comparative Effectiveness

• Daily 6.5 mg prasterone demonstrates at least equivalent efficacy to 0.3 mg conjugated estrogens or 10 μg estradiol for treating vulvovaginal atrophy symptoms 4
• Unlike vaginal estrogen preparations, prasterone maintains serum hormone levels within normal postmenopausal ranges without clinically significant systemic absorption 2, 3

Safety Profile and Monitoring

• The most common adverse event is application site discharge 2
• Serum concentrations of estrogenic and androgenic metabolites increase from baseline but remain within normal postmenopausal ranges during 52 weeks of treatment 2
• Prasterone does not carry an FDA boxed warning, unlike systemic estrogen therapies 3
• The FDA label warns that exogenous estrogens are contraindicated in women with a history of breast cancer, though limited supportive data exists for prasterone specifically in this population 5, 1

Special Populations and Contraindications

• Not recommended for use in pregnant or nursing women, as safety and effectiveness have not been established 1
• Not recommended for pediatric use 1
• Not recommended for use in men, as clinical studies involved only women 1
• Prohibited by certain athletic anti-doping regulations 1
• Pharmacokinetics have not been assessed in low body weight, obese patients, or those with renal or hepatic impairment 1

Treatment Algorithm Context

• Start with non-hormonal options first: vaginal moisturizers 3-5 times weekly plus water-based lubricants during sexual activity for 4-6 weeks 6
• Escalate to prasterone if symptoms persist or are severe at presentation, particularly for women on aromatase inhibitors who have not responded to conservative measures 5, 6
• For women with hormone-positive breast cancer, prasterone may be considered after thorough discussion of risks and benefits, as it is specifically recommended for aromatase inhibitor users who haven't responded to previous treatments 5, 6

Important Clinical Considerations

• Prasterone is metabolized to androstenedione, androsterone sulfate, estradiol, estriol, estrone, dihydrotestosterone, and testosterone in peripheral tissues 1
• Approximately 10-20% of prasterone is protein-bound, while 80-90% of its sulfated metabolite (DHEAS) is protein-bound 1
• Elimination half-life in elderly women progressively declines from approximately 12 hours (day 1) to 7 hours (day 15) 1