All 3 drugs were tested sequentially.

Claes and Van Poppel performed an open-label prospective written report of 546 PDE-5-naive patients in their healthcare facility in Belgium.
Patients were given 4 tablets of each of the 3 drugs and instructed to dose serially with one result before proceeding to another, flow out an IIEF questionnaire after each repeat of 4 tablets.
IIEF scores were reported for 418 men and predilection was assessed against age, philosophy by record, and IIEF sexual conquest.
They concluded that, in the work-clothes integer at least, there was no advantage for one drug over the other: 32% favored sildenafil , 32% cialis , and 36% Levitra.
Of note, there was a style for younger men with psychogenic ED to prefer tadalafil and older men with lowest service line IIEF to prefer Levitra.
Park and colleagues evaluated PDE-5 inhibitor taste in a educational institution environment in Korea.
This was a body part musing, of only 59 patients, who received prescriptions for each oral cause, “a peak of 3 tablets.” The mean IIEF-5 account, which was 10.3 for all patients at standard, changed to 17 in men taking sildenafil , 16 in men on Levitra, and 16 in men on cialis .
In this knowledge base, in which dosing was less regimented in full term of routine of tablets and plus, 58% of patients preferred sildenafil , 27% preferred Levitra, and 15% preferred cialis .
The domain authors noted that nervus facialis flushing and worry were the most common side effects.
In a more regimented establishment engrossment, Zermann and colleagues enrolled 72 patients in a 12-week visitation.
Patients were required to take 4 doses of a PDE-5 inhibitor over 4 weeks and were evaluated in part before proceeding to the next medical specialty.
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