The “Guidelines for Male Sexual Dysfunction” published by the European Society of Urology offer diagnosis and treatment for patients with erectile dysfunction (ED) and premature ejaculation. It has been updated seven times since its first release in 2000.
Drug treatment has completely changed the diagnosis and treatment of ED. The guide recommends initial treatment for ED patients: oral drug therapy (PDE5i), vacuum device therapy and shock wave therapy. Among these, PDE5i is very popular with doctors and patients because it works quickly and is easy to take. It is widely used in the clinic. However, the application and the issues to be considered during the application process also affect doctors and patients. Therefore, the interpretation of PDE5i in the General Practitioners Guide should help practitioners to use PDE5i more wisely.
Sex pills (Viagra)
PDE5 hydrolyzes cGMP in the cavernous tissue of the penis and inhibits PDE5 to relax smooth muscles and increase arterial blood flow, resulting in compression of the submental venous plexus and penile erection. These drugs cannot cause an erection, but do require sexual stimulation to promote an erection. The effect is that the penile erection is heavy enough to get into the vagina. Four effective selective PDE5I have been approved by the European Medicines Agency (EMA) for the treatment of ED.
It was first launched in 1998 and was the first PDE5i on the market with prescription doses of 25, 50 and 100 mg. The "Guide" recommends an initial dose of 50 mg, adapted to the effectiveness and side effects of the patient. After the patient has taken sildenafil for 30 to 60 minutes, the drug can play a therapeutic role and efficacy can be maintained for 12 hours. Patients who eat a high-fat diet may decrease the effectiveness of the drug due to prolonged drug intake. A dose-response study showed that the placebo group had an improvement in the erection rate of 25% after taking the drug for 24 weeks and the sildenafil 25, 50 and 100 mg group had an improved erection rate of 56%, 77%. or 84%.
It was approved for the treatment of ED in February 2003. It takes effect 30 minutes after taking the medicine. The effect is best after 2 hours and the effect can be maintained for 36 hours without being affected by the diet. The prescribed doses are 10 mg and 20 mg, which can be taken as needed, or a daily dose of 5 mg. The "Guide" recommends an initial dose of 10 mg, adapted to the effectiveness and side effects of the patient. A dose-response study showed that the placebo group had an improvement in erection rate of 35% after 12 weeks of taking the drug and the tadalafil 10 and 20 mg group had an erection improvement rate of 67% and 81%, respectively. Tadalafil is effective in the treatment of ED patients, including refractory ED (such as diabetes).
It was approved for the treatment of ED in March 2003 and came into effect 30 minutes after taking the drug. If the fat content in the diet is more than 57%, the effectiveness of the drug may be reduced. The prescribed doses are 5, 10 and 20 mg, which are taken as needed. The "Guide" recommends an initial dose of 10 mg, which should be adjusted to the efficacy and side effects of the patient. A dose-response study showed that the placebo group had an erection improvement rate of 30% after 12 weeks of taking the drug and the Vardenafil 5, 10 and 20 mg group had an erection improvement rate of 66%, 76% and 30% 80 %. Vandelafil is effective in the treatment of ED patients, including refractory ED (such as diabetes).
Highly selective PDE5I, which was approved by the EMA for the treatment of ED in June 2013. If required, prescribed doses of 50, 100 and 200 mg are taken. The “Guide” recommends an initial dose of 100 mg, which is taken orally if necessary, taken 30 minutes before the sex life and adjusted to the effectiveness and side effects of the patient. After taking the drug, the success rate of intercourse in the placebo group was 28% and the success rate of intercourse in the Avanafil 50, 100 and 200 mg groups was 47%, 58% and 59%, respectively. Within 15 minutes of administration, the effectiveness of Avanafil 50, 100 and 200 mg was 64%, 67% and 71%, respectively. The maximum recommended dose frequency is once a day and the dose adjustment does not depend on kidney function, liver function, age or gender. Compared to fasting, eating can delay the effects of avanafil, and this medicine can be taken on an empty stomach or after eating. Avanafil is effective in the treatment of ED patients, including refractory ED (such as diabetes).
To date, there is no data to investigate the efficacy and patient preference of the four drugs using multicentre double-blind or triple-blind methods. Patients must understand the properties of each drug (short or long) and possible side effects, and decide which PDE5i to use based on the frequency of sex life and the patient's experience.
Take on request or long term
Age, diabetes and surgical injuries can cause structural changes in the cavernous sinus. Animal studies have shown that long-term use of PDE5i can improve and prevent these changes, but human research data are still lacking.
Several studies have shown that long-term use of tadalafil significantly improves erectile function and is well tolerated. In 2007, the EMA approved Tadalafil 2.5 and 5 mg daily for the treatment of ED. Tadalafil 5 mg daily offers an alternative therapy on request for couples who prefer natural intercourse over planned intercourse or who expect frequent intercourse. The advantage of this therapy is that medication and sexual activity are no longer closely related. The drug can also be used for long-term treatment of patients with ED who are complicated with lower urinary tract symptoms.