I. Sildenafil tablets (Viagra) is a drug for male erectile dysfunction that was accidentally invented while developing drugs for cardiovascular disease. It is the citrate salt of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), which enables patients with erectile dysfunction to produce a natural erectile response to sexual stimulation. The recommended initial dose of sildenafil tablets is 50 mg for most patients, taken approximately 1 hour prior to sexual activity; however, it can be taken at any time between 0.5 and 4 hours prior to sexual activity. Based on efficacy and tolerability, the dose may be increased to 100 mg or decreased to 25 mg. Take up to 1 dose per day. It is recommended that patients taking Ritonavir should not exceed a maximum dose of 25 mg per 48 hours. Tadanafil (Xylazine) is a treatment for male erectile dysfunction that requires sexual stimulation for the product to work and cannot be used in women. The principle of action is the same as sildenafil and vardenafil, both rely on PDE-5 to increase the vasodilatory effect of NO by inhibiting the breakdown of cGMP, allowing ED patients to regain penile erection. The recommended dose of tadanafil is 10mg, taken before sexual intercourse, regardless of food intake. If 10mg is not effective, 20mg can be taken at least 30 minutes before sexual intercourse, with a maximum frequency of once daily. It is best not to take tadanafil continuously on a daily basis. It is best to use on an empty stomach, do not drink alcohol, strong tea, spicy food before use (the effect is significant when the user is in a sexually stimulated state). In clinical trials of herbal medicine, 4-5 hours before sexual intercourse, but still show the effectiveness of the drug. The maximum recommended frequency of dose use is once a day. Depending on efficacy and tolerability, the dose may be increased to 20 mg or decreased to 5 mg, with the maximum recommended dose being 20 mg daily. no dose adjustment is required for patients with mild hepatic impairment; the recommended starting dose is 5 mg for patients with moderate hepatic impairment; no dose adjustment is required for patients with mild, moderate or severe renal impairment. Albuterol can be taken with food or alone and requires sexual stimulation as an instinctive response to treatment. The main ingredient of Elidel is vardenafil hydrochloride, which is a light orange to dark orange film-coated tablet that appears white after removal of the film coating and can be used to treat erectile dysfunction in men. Vardenafil can be used to treat male erectile dysfunction by inhibiting phosphodiesterase type 5 (PDE5), which degrades cGMP in the human penile corpus cavernosum, and increasing the release of local endogenous nitric oxide in the corpus cavernosum under the effect of sexual stimulation, thus enhancing the natural response to sexual stimulation. The side effects of Elidel will not be significant, except that it may sometimes cause mild dilatation of peripheral blood vessels, which may manifest as facial flushing, dizziness, headache, nasal congestion, and indigestion. It is more likely to occur in sensitive people, but most of them are one-time, transient and mild, and will not affect sexual life, much less cardiovascular function.