PT-141 (Bremelanotide) in Women
Low sexual desire is a problem that occurs commonly in both women and men, which often causes much distress in relationships. Hypoactive sexual desire disorder (HSDD) is a condition characterized by a persistent lack of interest or desire for sexual activity; there is a lack of motivation for sex.
PT-141 (bremelanotide) modifies sexual brain processing in women with low sexual desire.
Vyleesi, approved in 2019, is only available as a subcutaneous injection yet some do not want to use the injection because of fear of needles (needle anxiety) or inconvenience. A nasal spray or lozenge may be an option for females unable to use the injection.
PT-141 (Bremelanotide) in Men
Erectile dysfunction and low sexual desire in men
The mechanism of how PT 141, (bremelanotide) works in men with erectile dysfunction (ED) or low sexual desire is more understood than how it works in women for sexual dysfunction. It is a peptide that works differently than other drugs for ED so can be tried where a male has not responded to other ED therapies. PT-141(bremelanotide) binds to melanocortin receptors in the brain to increase arousal and desire.
PT-141 (Bremelanotide) works differently than PDE5-Inhibitors
There are 5 melanocortin receptors (MC1-MC5) and in males, bremelanotide primarily acts on MC3R and MC4R to help with erectile dysfunction; they are excitatory. PT-141 Bremelanotide activates melanocortin which causes an increase in nitric oxide in the penis, leading to vasodilation and erection. PDE5 Inhibitors(Viagra/sildenafil/Cialis /tadalafil,etc) work by increasing blood flow to the penis.
PT-141 combined with PDE5-Inhibitors?
PT-141 (bremelanotide) may act independently, or, synergistically with PDE5 inhibitors inhibitors.
Nasal Spray combinations (dose and drug combinations customized for patients)
The main adverse effects of bremelanotide include brief increases in blood pressure (both systolic and diastolic), nausea, headache, and hyperpigmentation. Stimulation of the melanocortin receptors may lead to increased melanin expression, which may lead to hyperpigmentation.
Why some patients are prescribed bremelanotide in a nasal spray
- It’s not an injection- patients are often afraid of needles (needle anxiety) and pain from needles.
- Rapid absorption and possible faster onset of action compared to other forms of administration. Nasal mucosa has a rich blood supply and a large surface area, allowing for efficient absorption of medications directly into the bloodstream.
- Easy to administer: Nasal sprays are generally easy to use, non-invasive, and more convenient for individuals who may have difficulties with other routes of administration.
- Patient compliance: Nasal sprays are easy to use, often well-tolerated, and can be self-administered by patients.
Why some patients are prescribed bremelanotide lozenges (troches)
- It’s not an injection. People are often afraid of needles (needle anxiety) or pain from needles.
- Convenient administration: lozenges are typically easy to consume and do not require additional equipment or preparation. They can be conveniently taken anywhere without the need for water.
- They can be stored discreetly and easily administered without social interruption.
PT-141 (Bremelanotide) References
Novel Emerging Therapies for Erectile Dysfunction The erectile response induced by co-administration of PT-141 (bremelanotide) 7.5 m) and sildenafil (25 mg) was significantly greater than the response elicited by administration of sildenafil alone. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7752520/
Co-administration of low doses of intranasal PT-141 (bremelanotide), a melanocortin receptor agonist, and sildenafil to men with erectile dysfunction results in an enhanced erectile response https://pubmed.ncbi.nlm.nih.gov/15833522/
Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo-controlled study https://pubmed.ncbi.nlm.nih.gov/18206919/
PT-141: A Melanocortin Agonist for Sexual Dysfunction Administration of PT-141 to normal men and to patients with erectile dysfunction resulted in a rapid dose-dependent increase in erectile activity. https://nyaspubs.onlinelibrary.wiley.com/doi/abs/10.1111/j.1749-6632.2003.tb03167.x?sid=nlm%3Apubmed
See Table 1 Phase I Study
Summary for Intranasal in Men/Women https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8788464/
Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra.
The study evaluated PT-141 (Bremelanotide), in patients with erectile dysfunction (ED) who had an inadequate response to Viagra. Healthy subjects received doses from 0.3 to 10 mg, showing a significant erectile response at doses over 1.0 mg. ED patients received placebo, 4 mg, or 6 mg of PT-141 Bremelanotide in a crossover design during visual sexual stimulation (VSS). Both PT-141 doses induced a statistically significant erectile response. https://www.nature.com/articles/3901200
Melanocortin-4 receptor agonism modulates sexual brain processing in women with low sexual desire