You may never have heard of doxazosin, a generic drug, because what it doesn’t have going for it is a well-funded advertising campaign. Boehringer Ingelheim, the maker of Flomax, spent more than $115 million advertising Flomax to U.S. consumers in 2008. This helped rack up at least $1.2 billion in sales and make the drug one of the top 20 most commonly prescribed medications during that same year. It’s no coincidence that Flomax ads run during football games.

Another penalty against Flomax is that if you need a higher dose, you will pay twice. Flomax is available only in one strength, 0.4 milligrams. So men who need to increase their dose to 0.8 milligrams will need to take two pills, which doubles the cost. All other alpha-blockers are available in varying strengths for about the same price. Hence, if you need a stronger dose of the generic drugs, it won't cost you much, if any, more than a smaller dose.

So if you don’t want your wallet to "go with the flow," forget Flomax and try doxazosin, if you and your doctor decide you need a medication to treat symptoms of an enlarged prostate. It’s worth noting that by the time Super Bowl XLV rolls around next year, less costly generic versions of Flomax may be available. Flomax’s patent is expected to expire later this year and several generic manufacturers have already filed for FDA approval of their respective drugs. Whether the price of these generic drugs will be in line with that of doxazosin remains to be seen.

For more on enlarged prostate medications, check out our free Best Buy Drugs report and our video.

—Steve Mitchell, associate editor, Consumer Reports Best Buy Drugs

A word about the safety profile of Flomax. Some people may be under the impression that Flomax is potentially safer than doxazosin or other alpha blockers because of a belief that it doesn’t cause a drop in blood pressure. But that doesn’t hold up to scrutiny. Flomax (like other drugs in its same class, called alpha blockers) can cause orthostasis (a fall in blood pressure upon standing) and dizziness.

The studies we evaluated have not clearly shown any difference between doxazosin and Flomax in those side effects. Additionally, the drug labeling for Flomax clearly states in the warning section* the following: "The signs and symptoms of orthostasis (postural hypotension, dizziness and vertigo) were detected more frequently in FLOMAX capsule-treated patients than in placebo recipients. As with other alpha-adrenergic blocking agents there is a potential risk of syncope [passing out](see ADVERSE REACTIONS)."

However, with that in mind, your doctor should start you on a low dose of doxazosin when you first start taking it, and build up to a higher dose over a period of a few weeks to provide time for your body to adjust to the medicine.

Some have also suggested that anyone who is on a drug to control elevated blood pressure and who also begins taking an alpha blocker like doxazosin could be in serious trouble. While it is true that all alpha blockers do have the capacity to reduce blood pressure (that's the nature of this class of medications), studies show and the FDA-approved labeling states that doxazosin can be used in combination with other high blood pressure drugs, such as diuretics, beta-blockers, calcium channel blockers or ACE inhibitors.

Before you take any alpha blocker, including Flomax and doxazosin, you should use caution if combining medications, and also make sure your doctor knows about all the drugs you currently take. While there are several drugs to avoid (see here for full list) while using all alpha blockers, one type in particular is erectile dysfunction drugs, like sildenafil (Viagra), tadalafil (Cialis) or vardenafil (Levitra) since the combination can cause dangerously, or even life-threatening, low blood pressure.

*links to PDF