How long does it take to achieve the full effectiveness of Addyi (flibanserin)?

Time to Achieve Full Effectiveness of Addyi (Flibanserin)

Flibanserin (Addyi) reaches its full effectiveness after approximately 4 weeks (28 days) of daily use. 1

Pharmacokinetic Timeline

• Flibanserin reaches steady state plasma concentration after 3 days of consistent daily dosing 1
• Despite reaching steady state quickly, the clinical effects on sexual desire take longer to manifest 2
• The medication has a mean terminal half-life of approximately 11 hours, requiring daily dosing for maintained effectiveness 1

Clinical Response Timeline

• Unlike stimulant medications that show immediate effects, flibanserin requires consistent daily use for several weeks before patients experience the full therapeutic benefit 2
• Meta-analyses of clinical trials show that the full effects on sexual desire and function typically become apparent after 4 weeks of continuous use 3
• The medication should be taken daily at bedtime to minimize side effects like somnolence and dizziness while maintaining efficacy 1

Important Monitoring Considerations

• Patients should be evaluated for treatment response after 8 weeks of therapy 3
• If no improvement in sexual desire is noted after 8 weeks of continuous treatment, the medication should be discontinued 4
• Monitoring for adverse effects should be conducted throughout the initial weeks of treatment, with particular attention to hypotension, syncope, and CNS depression 1

Factors That May Affect Time to Response

• Hepatic function can significantly impact flibanserin metabolism, with impaired liver function increasing drug exposure 4.5-fold and extending the half-life to 26 hours 1
• CYP2C19 poor metabolizers may experience higher drug concentrations and potentially faster onset of effects, but also increased risk of adverse events 1
• Concurrent use of alcohol or CYP3A4 inhibitors can alter the medication's effectiveness timeline and increase risk of adverse effects 1

Efficacy Expectations

• Clinical trials demonstrated modest benefits with flibanserin, resulting in approximately one additional satisfying sexual event every two months compared to placebo 5
• Patients should be counseled about realistic expectations regarding the medication's effects and the timeframe for improvement 3, 4
• Unlike medications for erectile dysfunction that work on demand, flibanserin requires continuous daily dosing to maintain its therapeutic effect 1, 3