Muse™ Efficacy

MUSE™ (Medicated Urethral System for Erection, Vivus Inc.) is an alternative way to deliver alprostadil to the corporal bodies. MUSE™ involves the insertion of the delivery catheter into the meatus and depositing an alprostadil pellet in the urethra. One of the largest studies to describe the efficacy of MUSE™ was published by Padma-Nathan et al. Notable in this study, 995/1,511 patients had in-office responses to MUSE™. Of those patients with in-clinic response to MUSE™, only 299 of the 461 patients assigned to the MUSE™ arm of the trial achieved intercourse at home.

Thus, the true success rate of MUSE™ in this large study was only 42–44%. Furthermore, of the patients who did achieve intercourse at home, only 73% of doses (2,634/3,593) were successful in achieving intercourse, orgasm, or a 10 min erection sufficient for intercourse. MUSE™ is also efficacious in men who have undergone radical prostatectomy. Costabile et al. reported a 40% rate of at home success for MUSE™ in a group of 384 men greater than 3 months post-prostatectomy.

There are many direct comparison trials between MUSE™ alprostadil and ICI alprostadil. It is both intuitive and noteworthy that despite the higher success rate of ICI, some studies show that some patients prefer MUSE™. Additionally, it has been suggested as a possible rescue medication after ICI failure.

Administration Canadian viagra online 100mg

MUSE™ is available in doses of 100 mg, 250 mg, 500 mg, and 1,000 mg.

Instructions for application include urinating before use. Residual urine in the urethra aids in dis-solution and dispersal of the medicine along the urethra. The penis is then pulled straight and held pointing up. The 3.5 cm applicator stem is placed approximately 3 cm into the urethra and the button is depressed. The applicator is moved slightly to separate the pellet from the applicator tip and the applicator is removed. The penis is kept upright and rolled between the hands to aid in dissolution and dispersal of medication. The patient is then advised to walk or stand and not to lay flat for approximately 10 min to aid in blood flow.

Side Effects

MUSE™ alprostadil had similar rates of pain to ICI alprostadil, but priapism and fibrosis were rare. Other side effects unique to MUSE™ compared to ICI were dizziness, hypotension, and sweating. These occurred at a frequency of 1–6%. Syncope occurred at a rate of <1% and urethral bleeding also occurred at a rate of 1–5%. Malegra

One strategy for optimizing erectile function in PDE5 inhibitor failures while still avoiding ICI is to combine MUSE™ with PDE5 inhibitors. The theoretical basis of this is strong as sildenafil acts to improve and sustain erections, but does not help in initiation, whereas alprostadil jump-starts erection initiation in addition to aiding in maintenance of erections. Raina et al. published a small study of 23 post-prostatectomy patients unsatisfied with sildenafil. Patient satisfaction was measured using a questionnaire. An improvement from 38% satisfaction with sildenafil alone to 76% satisfaction with combined MUSE™/sildenafil was demonstrated.

Topicals Efficacy

Compared with both oral and injection therapies, topical routes are quite attractive. Theoretically, systemic effects are minimized compared to the oral route, and it is certainly less invasive, and thus would undoubtedly be more popular than injection or intraurethral therapies.

To date, however, no sufficiently effective product exists. Topical alprostadil was combined with agents to improve skin penetration (SEPA and NexACT). Vitaros, the combination of alprostadil and NexACT, formerly called Alprox-TD, was recently denied approval by the FDA due to potential carcinogenicity. In tri-als of alprostadil with SEPA, doses of 2,500 mg alprostadil were used with a resulting 39% of patients achieving erection sufficient for penetration versus 7% of the placebo group. Unfortunately, baseline characteristics were not provided in this study. Ultimately, alprostadil/ SEPA trials were discontinued because of their apparent lack of efficacy at safe doses.

A large trial of topical alprostadil without a skin penetration enhancer was also published by Padma-Nathan and Yeager which showed a statistically significant, but very slight improvement in sexual function with topical alprostadil. This study used 100, 200, and 300 mg doses of alprostadil and achieved successful penetration rates of 57.5%, up from a baseline of 50% at the highest dose. A criticism of this study is that its high initial function rates do not adequately represent population seeking treatment for erectile dysfunction.

Topical minoxidil, nitroglycerin, and papaverine were also tested variably alone and with skin penetration enhancers, but with little success.