ISSN:
1432-1041
Keywords:
Key words Tamsulosin
;
Protein binding
;
Renal disease
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Objective: To investigate the factors that affect the plasma protein binding of tamsulosin in patients with lowered renal function compared with that in healthy subjects and to evaluate the possibility of binding interactions. Methods: Blood was donated from patients with renal dysfunction and from healthy subjects. The binding of 14C-tamsulosin to plasma proteins was determined by the ultrafiltration method. In addition, plasma protein binding interactions were investigated between tamsulosin and other drugs used concomitantly. Results: The mean percentage of unbound 14C-tamsulosin was 0.90% in the healthy subjects (control) and was 0.71% in the patients. The unbound fraction in the patients with α1-acid glycoprotein (α1-AGP) levels over 0.9 mg/ml was significantly lower than that in the healthy subjects. In contrast, the unbound fraction in the patients with α1-AGP levels less than 0.7 mg/ml, which is the mean normal level, was almost equal to the control levels. A significant correlation existed between the Cb/Cu of tamsulosin and plasma α1-AGP level (r 2 = 0.580, P 〈 0.001), while no correlation existed between the Cb/Cu and plasma albumin level (r 2 = 0.021, P = 0.381) in both groups. No apparent binding interactions were observed between tamsulosin and the other drugs examined. Conclusions: Tamsulosin is highly bound to α1-AGP. The extent of plasma protein binding of tamsulosin correlated with the α1-AGP level but not with the albumin level. Furthermore, there appears to be no or little possibility of binding interactions between tamsulosin and other drugs in clinically concomitant use, despite its strong binding to α1-AGP.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002280050653
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