Metabolism (breakdown) of sildenafil is slowed by aging, liver and kidney dysfunction, and concurrent use of certain medications (such as erythromycin -- an antibiotic, and protease inhibitors, for HIV). Slowed breakdown allows sildenafil to accumulate in the body and potentially may increase the risk of side effects. Therefore in men over 65, in men with substantial kidney and liver disease, and in men who also are taking protease inhibitors, the doctor will initiate sildenafil at a lower dose (25 mg) to avoid accumulation of sildenafil in the body. A protease inhibitor ritonavir (Norvir) is especially potent in increasing the accumulation of sildenafil, thus men who are taking Norvir should not take sildenafil doses higher than 25 mg and at a frequency of no greater than once in 48 hours. click to buy cialis buy cialis How common is erectile dysfunction - Erectile dysfunction (ED, impotence) varies in severity; some men have a total inability to achieve an erection, others have an inconsistent ability to achieve an erection, and still others can sustain only brief erections. The variations in severity of erectile dysfunction make estimating its frequency difficult. Many men also are reluctant to discuss erectile dysfunction with their doctors due to embarrassment, and thus the condition is underdiagnosed. Nevertheless, experts have estimated that erectile dysfunction affects 30 million men in the United States. How should tadalafil (Cialis) be administered? The recommended starting dose of tadalafil for most patients is 10 mg taken orally approximately one hour before sexual activity. The dose may be adjusted higher to 20 mg or lower to 5 mg depending on efficacy and tolerability. The maximum recommended dosing frequency is once per day, although for many patients tadalafil can be taken less frequently since the improvement in erectile function may last 36 hours. Tadalafil may be taken with or without food. best price cialis cialis Levitra Information from Drugs.com buy levitra buy cialis buy cialis online In life of any man there can come the moment when sexual energy will leave it viagra online
