That means seven out of 10 people who take these drugs as prescribed will have more frequent or longer-lasting erections. The dose of CIALIS for use as needed should be limited to 10 mg no more than once every 72 hours in patients taking potent inhibitors of CYP3A4 such as ritonavir, ketoconazole, and itraconazole [see Drug Interactions 7. If you are taking tadalafil for erectile dysfunction, your doctor will probably start you on an average dose of tadalafil and increase or decrease your dose depending on your response to the medication. It’s best to check your chosen provider’s site for more information. It depends on the platform and insurance provider.AdSave on 50, Brand Name & Generic Drugs With SingleCare®. Get Your Free Rx Coupon Now! Save Up to 80% on Prescriptions at ONABP certifiedTypes: Maintenance, Accute, Branded, Generic. headache. indigestion. back pain. muscle pain. flushing. stuffy nose. Patients who get back pain and muscle aches usually get them 12 to 24 hours after taking Cialis and these usually go away by. 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 .