일부 환자에서 비아그라를 사용하는 도중에
약효가 반감 되는 현상을 보였다.

일부는 약물 복용을 중단하였으며
일부는 약불의 용량을 증가시켰다.


제목
Viagra May Not Work Long-Term for Some Patients
(Reuters/ August 30, 2001)


Viagra, the popular anti-impotence drug, may stop working for many patients after 2 years, the results of a study suggest.

In August 1998, Dr. Rizk El-Galley of the University of Alabama at Birmingham and colleagues interviewed 151 men who had filled prescriptions for Viagra in 1997. Overall, 74% reported that 25 milligrams (mg) to 100 mg of the drug enabled them to initiate and maintain erections sufficient for intercourse.

The improvement rate ranged from 50% for patients with impotence caused by diabetes, to 78% for those with no specified reason for impotence, to 100% for those with suspected leakage in their veins.

In August 2000, the investigators re-interviewed 82 of the men, of whom 43 were still using the drug. Sixteen of those 43 (37%) said they had needed to increase the dose by 50 mg to achieve an adequate erection. It had taken between 1 and 18 months for the treatment to lose its effects. There was no correlation between the need to increase the dose and frequency of use.

"In general, 81% of patients who were still receiving treatment were satisfied, and 92% were able to achieve and maintain erections sufficient for sexual intercourse in more than 50% of attempts," El-Galley and colleagues write in The Journal of Urology for September.

Of the 39 patients who had stopped taking Viagra, 28 had initially reported a good response. Fourteen of those patients who stopped said the drug no longer worked, and six said they had regained the ability to have spontaneous erections.

(Journal of Urology 2001;166:927-931)