Common side effects include headache, facial flushing, indigestion, and dizziness. 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. Most erectile dysfunction medications belong to the drug class known as PDE5 inhibitors , which help relax the muscles and increase blood flow to allow for a full erection. How should this medicine be used? The active ingredient can remain longer if you have problems with your kidneys or liver, or you are taking certain other medications.CIALIS for Use as Needed. Creatinine clearance 30 to 50 mL/min: A starting dose of 5 mg not more than once per day is recommended, and the maximum dose is 10 mg not more than once in every 48 hours. Creatinine clearance less than 30 mL/min or on hemodialysis: The maximum dose is 5 mg not more than once in every 72 hours [see . Men who get back pain and muscle aches usually get it 12 to 24 hours after taking Cialis. Back pain and muscle aches usually go away within 2 days. Call your healthcare provider if you get any side effect that bothers you or one that does not go away. Uncommon but serious side effects include. Our medical team can give you a prescription for sildenafil 20mg. The Lemonaid Pharmacy can deliver it to you for $2/pill, including FREE delivery. Our medical team can prescribe .