The Effect of Age on the Pharmacokinetics of Udenafil in Healthy Subjects

Udenafil, a cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5) inhibitor, has been developed to treat erectile dysfunction. We evaluated the effect of age on the pharmacokinetics and tolerability of udenafil.

A single-center, open-label, parallel-group phase 1 study was conducted in healthy adult subjects who took a single oral dose of udenafil (100 mg). The pharmacokinetics and tolerability of udenafil were compared between 12 healthy young males (21-27 years) and 12 healthy elderly males (65-78 years). Serial blood and urine samples were collected for up to 60 h and 48 h after dosing. The plasma concentrations of udenafil and its major metabolite, DA-8164, were analysed using a validated liquid chromatography-tandem mass spectrometry method. The mean Cmax of udenafil tended to be slightly less (214.0 vs. 292.8 μg/L) in the elderly compared with the young (GMR: 68.9, 95% CI: 48.9-97.1); however, the AUC did not differ between the groups (1858.8 vs. 2100.6 μg·h/L, GMR: 84.6, 95% CI: 66.1-108.4). The mean t1/2 was prolonged by approximately 5 h in the elderly (p < 0.05). The clearance and metabolic AUC ratio did not differ between the elderly and young. In terms of tolerability, all adverse events were mild, and all subjects recovered without additional therapy. The systemic exposure of elderly subjects to udenafil appears to be comparable to or slightly less than that of young healthy subjects. Based on our pharmacokinetic comparisons, udenafil dose adjustment is unlikely to be required in the elderly population. This article is protected by copyright. All rights reserved.

Journal of clinical pharmacology. 2016 Mar 23 [Epub ahead of print]

Hyang-Ki Choi, Jin Ah Jung, Mi Young Bahng, Doo-Yeon Cho, Chang Woo Yeo, Eun-Young Kim, Jae-Gook Shin

Department of Pharmacology, Inje University College of Medicine, 75 Bokji-ro, Busan Jin-gu, Busan,, 47392, Republic of Korea., Department of Pharmacology, Inje University College of Medicine, 75 Bokji-ro, Busan Jin-gu, Busan,, 47392, Republic of Korea., Dong-A ST Co., Ltd., 64 Chunhodae-ro, Dong Dae Moon-gu, Seoul, 02587, Republic of Korea., Department of family medicine, Ajou University Hospital, 46 49-kil, Kwangkyojungang-ro, Young Dong-gu, Suwon, 16500, Republic of Korea., Department of Pharmacology, Inje University College of Medicine, 75 Bokji-ro, Busan Jin-gu, Busan,, 47392, Republic of Korea., Department of Pharmacology, Inje University College of Medicine, 75 Bokji-ro, Busan Jin-gu, Busan,, 47392, Republic of Korea., Department of Pharmacology, Inje University College of Medicine, 75 Bokji-ro, Busan Jin-gu, Busan,, 47392, Republic of Korea.