You can take this medicine with or without food 30 minutes before sex, depending on the dose. If you are taking tadalafil to treat PAH or BPH, follow your doctor’s directions and the guidelines in this paragraph. Alternatively, Cialis may be prescribed as an as-needed treatment for ED, to be taken before sexual activity. This medicine works best when you take it on an empty stomach an hour before sex. Tadalafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow more easily. Counterfeit medicines can be very dangerous. If you are thinking about using tadalafil please discuss it with your doctor.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 . Tadalafil is a medicine used to treat erectile dysfunction (ED, also called impotence) and problems with urination caused by an enlarged prostate (benign prostatic hypertrophy or BPH). It is sometimes known by its generic name tadalafil, and sometimes known by its trade name, Cialis. There are also other brands of this medicine available. Cialis Prices, Coupons and Patient Assistance Programs. Cialis is a member of the impotence agents drug class and is commonly used for Benign Prostatic Hyperplasia, and Erectile Dysfunction. The cost for Cialis oral tablet mg is around $ for a supply of 30 tablets, depending on the pharmacy you visit.