Medical Management for BPH: The Role of Combination Therapy

The Long-Term Outcome of Medical Therapy for BPH

OBJECTIVES

The lack of cure with medical therapy implies life-long treatment emphasising the need for a thorough understanding of the long-term outcome. We review the natural history, markers for progression, placebo effect, efficacy, pharmacoeconomic aspects, and preventive measures.

METHODS

Literature review with particular reference to long-term controlled studies using plant extracts, alpha1-blockers, 5alpha-reductase inhibitors (5-ARIs), and combination therapy.

RESULTS

There is a long-lasting (>or=12 mo) placebo response of symptoms (20% decrease) and maximum flow rate (10% rise). The five long-term controlled trials of plant extracts are inconclusive and therefore their role in contemporary medical management is still controversial. The alpha1-blockers provide fast amelioration of symptoms yet have no relevant impact on the risk of acute urinary retention or surgery. Combination therapy should be reserved for moderately or severely symptomatic patients with a high risk of progression; in the majority of patients the alpha1-blocker can be safely stopped after 6-12 mo. The preventive use of 5-ARIs in men with no or mild symptoms at risk of progression is scientifically sound yet not generally accepted mainly for economic reasons.

CONCLUSIONS

A sharp contrast exists between the duration of the longest controlled trial (4.5 yr) and the situation in real life with treatment periods up to one or two decades of life. Real-life and registry data will be the only source of this important information in the future.

A rapid, simple, specific liquid chromatographic-electrospray mass spectrometry method for the determination of finasteride in human plasma and its application to pharmacokinetic study

A fast, accurate, sensitive, selective and reliable method using reversed-phase high-performance liquid chromatography-mass spectrometry coupling with an electrospray ionization interface was developed and validated for the determination of finasteride in human plasma. After deprotienation with acetonitrile, centrifugation, evaporation to dryness and dissolving in mobile phase, satisfactory separation was achieved on a Hypersil-Keystone C(18) reversed-phase column using a mobile phase consisting of acetonitrile-water (46:54, v/v), 0.1% acetic acid and 0.1% trifluoracetic acid. Carbamazepine (IS) was used as internal standard. This method involved the use of the [M+H](+) ions of finasteride and IS at m/z 373 and 237 with the selective ion monitoring (SIM) mode. The calibration curve was linear in the range of 0.2-120 ng ml(-1). The limit of quantification for finasteride in plasma was 0.2 ng ml(-1) with good accuracy and precision. The intra-assay precision and accuracy were in the range of 2.1-11.2% and -1.3% to 8.5%, respectively. The inter-assay precision and accuracy were in the order of 3.4-12.1% and -1.5% to 11.5%, respectively. The mean sample extract recoveries of the method were higher than 85% and 74% for finasteride and internal standard (IS), respectively. The assay has been successfully used to estimate the pharmacokinetics of finasteride after oral administration of a 5mg tablet of finasteride to 24 healthy volunteers.