Manufacturers recommend spironolactone be taken at the same time every day, with or without food.1,2 They state that food increases the bioavailability of spironolactone as measured by area under the curve by 95.4%. For this reason, manufacturers recommend a consistent pattern related to meals and drug dosing.
Two studies (of nine3 and eight4 healthy volunteers, respectively) compared the availability of spironolactone and one or more of its metabolites between the fasting and fed state and consistently found that food promotes the absorption of spironolactone.5
However, one Chinese study of 40 male subjects tested the bioavailability of spironolactone and one of its metabolites, canrenone, between the fasting and fed state. The authors of this study found spironolactone and its metabolite to be bioequivalent in the fasting and fed condition.6
Spironolactone has a short half-life of only two hours and is broken down into three major metabolites each with different half-lives, that contribute to its clinical effect.7
References
- Aldactone (spironolactone) [package insert].New York, NY: Pfizer Labs; 2018.
- Spironolactone [package insert]. In: Mylan Pharmaceuticals. Morgantown, WV; 2015.
- Overdiek HW, Merkus FW. Influence of food on the bioavailability of spironolactone. Clin Pharmacol Ther 1986; 40 (5): 531-536.
- Melander A, Danielson K, Schersten B, Thulin T, Wahlin E. Enhancement by food of canrenone bioavailability from spironolactone. Clin Pharmacol Ther 1977; 22 (1): 100-103.
- Karim A. Spironolactone: disposition, metabolism, pharmacodynamics, and bioavailability. Drug Metab Rev 1978; 8 (1): 151-188.
- Li Z, Deng Y, Cai H, et al. Pharmacokinetic properties and bioequivalence of spironolactone tablets in fasting and fed healthy Chinese male subjects. Int J Clin Pharmacol Ther 2016; 54 (6): 455-461.
- Kolkhof P, Barfacker L. 30 years of the mineralocorticoid receptor: Mineralocorticoid receptor antagonists: 60 years of research and development. J Endocrinol 2017; 234 (1): T125-T140.
