What if I am taking other drugs? Check the healthdirect’s medicines section for more information about tadalafil. Some people buy tadalafil online without a prescription. 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. Tadalafil belongs to a group of medicines called phosphodiesterase 5 PDE5 inhibitors. Cialis will be available by prescription only.Best prices for generic cialis on the Internet! The safest way is to ask your physician to try an alternate prescription. Detailed dosage guidelines and administration information for Cialis (tadalafil). Includes dose adjustments, warnings and . The recommended starting dose for Cialis intended for once daily use is mg, take at the same time each day, without regard to timing of sexual activity. This may be increased to 5mg/day based on need and tolerability. May be taken with or without food. Cialis is available as a generic, under the name tadalafil. 3. Dosage range: mg to 5 mg. Frequency: once daily, regardless of the timing of sexual activity. Cialis’s recommended dosage when it’s taken as needed for ED is as follows. Dosage range: 5 mg to 20 mg. Frequency: one dose at least 30 minutes before sexual activity, with a maximum of one dose per day*.