Albert I. Wertheimer, Ph.D., professor of pharmacy administration at Temple University School of Pharmacy, and Patricia J. Bush, Ph.D., professor emeritus at Georgetown University School of Medicine, are co-authors of "Your Drugs & Sex: How Prescription and Non-Prescription Drugs Can Affect Your Sex Life."

Q. Are generics the same as brand-name drugs?

A. Yes - and no. Years ago, after being prescribed a brand-name hydrocortisone ointment to treat poison ivy, one of us (Patricia) went to the pharmacy. She joked, "I'm a pharmacist, so you're going to give me a discount, aren't you?" He smiled and said "Sure" - and added, "Well, then, you won't mind getting the generic."

Indeed, a study published this year found that pharmacists overwhelmingly said they preferred generic rather than brand name over-the-counter medicines for themselves.

The word generic means "common to" or "characteristic of" a whole group or class. The federal Hatch-Waxman Act of 1984 permitted the Food and Drug Administration to approve generic medicines. This does not refer to inactive ingredients such as the color or coating or to the delivery system, e.g., tablet or capsule, or even to the amount of active ingredient. It refers to the amount of active ingredient that has similar bioavailability to the original brand-name product after it is taken.

For example, if the brand-name drug releases 30 mg of drug over six hours, the generic equivalent must do the same. So generics and brand-name drugs do not have identical inactive ingredients.

But they are the same relative to the characteristic that matters: the amount of active ingredient that the FDA found was within the acceptable bioequivalent range as the original brand-name product in your body.

Some patients may be allergic to the dye or other inactive ingredient in a generic version and will need to use the original brand or a different generic, if one is available. For the same reason, some patients fare better with a generic than the branded version.

Brand-name and generic are not the same when it comes to cost.

In 2014, it was estimated that 88 percent of prescriptions were dispensed as generics - yet accounted for just 28 percent of the costs. In Pennsylvania, the estimated generic savings was almost $12 billion.

On average, since 2008, the cost of brand-name drugs has been increasing and the cost of generics has been decreasing.

Why aren't there more generics? The patent for an original drug is for 20 years from the date the manufacturer files an application. The FDA takes five to eight years to review it, reducing the manufacturer's time frame in which to make back the probably $1 billion-plus in research and development expenses, which may include three phases of clinical trials. Sometimes during the clinical trial, a new use is found for it, so the patent life may be extended. This happened with Viagra, which in trials was also found to help treat high blood pressure in the lungs, so the patent was extended to 2020.

Patent extension is sometimes granted by the FDA for an "orphan drug," for conditions so rare that a company is unlikely to turn a profit in the usual 20-year patent life.

When a new brand-name drug is successful, a competitor's product can be expected within three years. So the company making the original drug has only three to four years to recover its investment and make a profit.

To see whether a generic is available for your brand-name drug, simply Google the brand name and see if a generic name appears next to it..

Would you take a generic drug? These pharmacists would.