Interactions between medications employed in treating benign prostatic hyperplasia and food - A short review

Benign prostatic hyperplasia (BPH) is the most common disease in elderly men. BPH symptoms include frequent urination, urgent tenesmus and urination at night, a weak and interrupted urine flow and a sense of incomplete emptying of the bladder. Alpha- 1 adrenergic receptor antagonists and 5 α-reductase inhibitors form the most important groups of medications employed in BPH. Appropriately managed BPH patients shall be subject to counselling on interactions between agents belonging to these groups, and on particular components of the food they have. The present review has been aimed at assessing potential effects of consumed food, alcohol and fruit juices on the pharmacokinetics and pharmacodynamics of medications for benign prostatic hyperplasia. The authors reviewed the English PubMed database covering the years 1991-2015. Additionally, a digital version of Stockley Drugs Interaction and other electronic databases such as drugs.com and Medscape were also researched; characterisation charts for particular medical products were also analyzed. Pharmacokinetics of extended-release forms of alfuzosin, doxazosin, tamsulosin and silodosin is well known to be food-sensitive. Alfuzosin, tamsulosin and silodosin due to their likely interaction with grapefruit juice and citrus fruits, may intensify adverse effects of the drugs. Alpha-1 adrenergic receptor antagonists are known to interact with alcohol, leading to orthostatic hypotension. For 5 alpha-reductase inhibitors, such as finasteride, or dutasteride, the pharmacokinetic effect due to consumed food is of no clinical importance and thus they may be taken regardless of meals. As in general grapefruit juice and alcohol tend to significantly affect the efficacy and safety of the applied drug therapy, it is highly advisable to be knowledgeable on the subject in order to educate patients.