Viagra originally developed to treat angina sufferers was later discovered to help the cause of erectile dysfunction. Levitra is relatively a new revolutionary drug used to treat Erectile Dysfunction also.
Viagra works in about 30 minutes and lasts for at least 4 hours. Peak levels of erection were reached in mean times of 30 minutes and 36 minutes after taking Levitra.
Levitra stayed active and working in the system for an average of 12 hours in patients 65 years or older, and 9 and a half hours in younger participants.
Clinical studies have shown that Viagra has the ability to remain in the system for up to 4 hours.
When a man is sexually aroused, certain tissues in his penis relax. This allows large amounts of blood to flow in, thus producing an erection.
Viagra helps by elevating the levels of the chemical that causes the tissues to relax. Levitra acts in the same way as Viagra, by blocking an enzyme called phosphodiesterase-5, or PDE-5. This helps the smooth muscles in the penis to relax, which effectively increases blood flow.
Drug: Levitra Manufacturer: Bayer Date Introduced: April 2003 Dosage Levitra: 5 mg, 10 mg, 20 mg Average Approx: Absorbtion Rate 40 Minutes Duration Of Effectiveness: 4 Hours Reported Side Effects Lelitra: Headache, Flushing, Dyspepsia, Nasal Congestion Congestion, Diarrhea, Flushing, Headaches, Urinary Tract Infection, Bluish Vision Contraindications: Any Nitrate-Based Medicine
Drug: Viagra Manufacturer: Pfizer Date Introduced: March 1998 Dosage Viagra: 50mg, 100 mg Average Approx: 40 Minutes Duration Of Effectiveness: 4 Hours Reported Side Effects Viagra: Headache, Flushing, Dyspepsia, Nasal Congestion Congestion, Diarrhea, Flushing, Headaches, Urinary Tract Infection, Bluish Vision Contraindications: Any Nitrate-Based Medicine
Viagra achieved a success rate of 60-80 per cent, depending on the dosage, in trials. However, it doesn't always work first time as claimed by some.
Levitra, by comparison, works for 72-90 per cent of men the first time and goes on to work 95 per cent of the time. Blue discoloration of vision (overlap with PDE-6 in the retina) is seen only with Viagra (<0.5%), whereas headache, facial flushing, and mild indigestion were observed with Levitra.
Viagra can cause some visual problems, including, an increased sensitivity to light, blurred vision, or an inability to tell the difference between blue and green.
Viagra is available in the strength and pack of 50mg, 100mg (4-8 comp.) / 100mg (30 tablets USA) whereas Levitra is available in 5mg, 10mg and 20 mg. 4 or 8 comp.