Can alpha-blocker drugs and 5-alpha reductase drugs be used together?
The short answer to this question is yes. For several years, many urologists used these drugs together with the rationale that because their mechanisms of action were different, their benefits might be additive; however, there was no objective proof that this really was so. In 2003, the MTOPS (The Medical Therapy of Prostate Symptoms) study was published in the New England Journal of Medicine (2003;349). It looked at whether a combination of both kinds of drugs was better than either drug alone.
This study was a double-blind (neither the investigator or study participants knew who received drug(s) or placebo) trial that involved more than 3,000 men who were followed for an average of 4.5 years. The men were divided into four groups: placebo (control group), doxazosin (an alpha blocker) alone, finasteride alone, and doxazosin and finasteride together. These four groups of patients were then followed for signs of progression of BPH. Progression was defined as an increase of urinary symptoms, as measured by the American Urological Association symptom score, acute urinary retention, urinary incontinence, renal insufficiency, or recurrent urinary tract infections. The risk reduction of signs of progression of BPH was 39% with doxazosin, 34% with finasteride, and 66% with combination therapy.
MTOPS proved that the two classes of drugs used together were superior compared with either type of drug alone; however, the practical issue is cost. Obviously, two drugs cost more than one. Therefore, in most cases, the physician will start treatment with one class of drug or the other and add the second drug only if the response to the first drug alone is not satisfactory.
What are LUTs?
Lower urinary tract symptoms is a term used to apply to both storage and emptying symptoms. In the field of urology, this term has replaced BPH sx. BPH symptoms are part of the voiding phase lower urinary tract symptoms (LUTs).
LUTs include storage and voiding symptoms. Storage (overactive bladder) symptoms include urinary frequency (voiding eight or more times per day), urinary urgency (a sudden compelling desire to void that is difficult to defer), nocturia, and urgency urinary incontinence.
Voiding symptoms include decreased force of stream, hesitancy, straining to void, postterminal dribbling, and intermittency of the urine stream.
A significant number of men presenting with voiding symptoms suggestive of underlying benign prostatic hypertrophy will also have storage symptoms, thus the term LUTs would be more appropriate in these individuals. Medical therapy designed to treat the voiding phase symptoms may or may not lead to improvement in the storage symptoms. Men may have underlying overactive bladder in addition to BPH and studies have demonstrated that with relief of the outflow obstruction associated with BPH there may be improvement in the overactive bladder symptoms. However, in men undergoing transurethral prostatectomy for BPH, 30% of men after relief of their bladder outlet obstruction, had persistent overactive bladder symptoms.
What happens if storage (overactive bladder) symptoms persist after successful treatment of the voiding symptoms?
In males with LUTs in whom the voiding (BPH) symptoms have been successfully treated, but whose overactive bladder symptoms persist, a trial of antimuscarinic therapy can be tried if there is no contraindication to the use of antimuscarinic agents. Your doctor will want to make sure that you are emptying your bladder well before using an antimuscarinic. There are a variety of antimuscarinic agents available (Table 13). They all are effective in decreasing urinary frequency, urgency, and urgency
Table 13. Antimuscarinic Dosing, Pharmacokinetics, and Metabolism
incontinence episodes. The most common side effects of the antimuscarinics are dry mouth and constipation. Rarely, some may affect cognition (memory and learning) or cause visual disturbances. These medications are contraindicated in individuals who have a history of narrow angle (the less common type of glaucoma) glaucoma, gastric (stomach) emptying problems, and urinary retention. If you have any concerns regarding potential side effects or interactions with any of your current medications it is important to talk to your doctor.
