Do not stop taking tadalafil without talking to your doctor. There are two different ways to take tadalafil, either daily or on an as needed basis. For treatment of erectile dysfunction daily use : Adults—2. How should this medicine be used? What special precautions should I follow? Take all of the tablets for your daily dose at one time each day; do not divide the tablets to take as separate doses.The usual starting dose for once-daily Cialis is mg. Your doctor might increase the dose to 5 mg based on how you react to the medication. Take one tablet as prescribed at the same time each day.  · Cialis can be taken as needed or every day for ED. But the dosage is different based on how you’re taking it. The as-needed Cialis dosage for ED ranges from 5 mg to .  · Taking higher dosages of Cialis than this, such as 40 mg per day, raises your risk for serious side effects. Examples of these side effects include very low blood pressure and priapism (a painful.