Cialis should not be used by patients taking nitrates such as nitroglycerin tablets or patches because the combination of these with Cialis could significantly lower blood pressure and lead to fainting or even death in some men. Because patients with recent heart attacks or stroke, heart pains angina , heart failure, uncontrolled blood pressure or uncontrolled irregular heart beats, severe liver disease, and retinal eye problems were not studied with Cialis, Cialis is not recommended for these patients. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Click here for an email preview. Cialis will be available as oral tablets in 5mg, 10mg and 20mg strengths. There may be rare occurrences of priapism or painful, prolonged erections.Cialis lasts up to 36 hours in the body, while Viagra lasts 4–6 hours in the body. Both are taken 30 minutes before sex. Cialis can cause limb pain, while Viagra can cause vision change, rash. Cialis comes as oral tablets that are available in four strengths: milligrams (mg), 5 mg, 10 mg, and 20 mg. Recommended dosage for Cialis Typically, . Hims offers brand name Cialis as a monthly supply of 5-mg tablets that can be taken daily. Generic Cialis (tadalafil) is available in mg, 5-mg, mg, mg, and mg tablets for daily or as.