Sildenafil side effects

Gresser U, Gleiter CH. Erectile dysfunction comparison of efficacy and side effects of the PDE-5 inhibitors sildenafil, vardenafil and tadalafil review of the literature. Eur J Med Res 2002 7 435-446. 

Several medications have been suggested as antidotes for the sexual side effects associated with antidepressant therapy. Bupropion, 75 or 150 mg/day, has been added to an SSRI regimen with some success in terms of improving libido (Labbate and Pollack 1994). Sildenafil has been used on an as-needed basis before sexual activity (Fava et al. 1998). 

Its impact on erectile dysfunction was discovered as a side effect in the clinical trials for angina efficacy. Because sildenafil s target was unknown, Pfizer spent additional time researching the biological processes behind sildenafil s erectile dysfunction activity. This research explains the gap between the original synthesis of sildenafil and its advancement to a commercial process. 

Sitaxsentan is a potent and selective agent which inhibits ET-1 binding to ETA receptors (IC50 = 1.4 nM), while being essentially inactive at ETB receptors (IC50 = 9.8 pM).23 In the clinic, it was found to have excellent oral bioavailability (70-100%) and a terminal elimination half-life of 10 h, and is administered as a once daily 100 mg dose. It is highly protein bound in plasma (> 99%) and extensively metabolized in the liver to inactive metabolites, predominantly by CYPs 2C9 and 3A4. Excretion is 50 60% renal, with the balance in the feces.25 Sitaxsentan inhibits CYP 2C9, and was observed to increase exposure to warfarin by over twofold. The use of cyclosporine A is also contraindicated, but no interactions were observed with sildenafil.15 Sitaxsentan was well tolerated in trials, with only minor side effects reported. Reversible liver enzyme abnormalities were also observed, but less frequently than with bosentan.15 25... 

Side effects are based on the dose and are noted 15-30 minutes after ingestion (peak 60 minutes) corresponding to blood drug concentration (sildenafil). Keep doses <100mg... 

Dose-related incidence of ocular side effects (sildenafil) ... 

Sildenafil citrate is effective in ti eating erectile dysfunction in several neurodegenerative diseases. What side effect can tliis medication cause in Pai kinson disease ... 

Vobig, M.A. Klotz, T. Staak, M. Bartz-Scmidt, K.U. Engelmann, U. Walter, P. Retinal side-effects of sildenafil. The Lancet 1999, 353-375. 

Dundar M, Kocak 1, Dundar SO, Erol H. Evaluation of side effects of sildenafil in group of young healthy volunteers. Int Urol Nephrol 2001 32(4) 705-8. 

Vobig MA, BQotz T, Staak M, Bartz-Schmidt KU, Engelmann U, Walter P. Retinal side-effects of sildenafil. Lancet 1999 353(9150) 375. 

Vobig MA. Retinal side-effects of sildenafil. Lancet 1999 353(9162) 1442. 

B Sexual dysfunction is generally believed to be a dose-dependent side effect with SSRIs and may be relieved or prevented with lower doses. Although RH may run the risk of relapse at a lower dose, many patients will achieve a therapeutic response at lower doses. If this approach is unsuccessful, bupropion is an excellent antidote and may also provide additional antidepressant effects (i.e., augmentation). Sildenafil has actually been found to reverse SSRI-induced sexual dysfunction but is an expensive alternative with potential cardiovascular complications that should only be considered after other measures fail. 

Adverse Effects. Sildenafil is well tolerated in patients with normal cardiovascular function. Most of the side effects reported in the clinical trials at a higher rate than placebo are mild and are related to the drug s vasodi-latory effect. They include headache, flushing, and nasal congestion. Other frequent side effects include abnormal vision (impairment of color discrimination) and dyspepsia. The... 

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