Drugs are complex substances, and they may have as many as three different names: chemical, generic, and brand. Chemical names are long and difficult to pronounce. The U.S. Food and Drug Administration approves the generic, shortened names by which drugs are usually known. Drug companies give their products brand names.

For example N-(4-hydroxyphenyl) acetamide is the chemical name for acetaminophen, which is the generic name for Tylenol. Many nonprescription and prescription pain relievers are available under both generic and brand names. Your doctor or pharmacist can tell you the generic name. Generic products tend to be less expensive than brand-name drugs and usually are just as effective.

However, because of differences in manufacturing methods, medicines with the same generic name produced by different companies may differ in the way they are absorbed by the body. For this reason, your doctor may prefer that you take a brand-name drug. You might want to ask your doctor or pharmacist if you can use a less expensive medication. Pharmacies are careful to obtain high-quality generic products, so it is sometimes possible to make substitutions.

Are Aspirin, Acetaminophen, and Ibuprofen Different?
Yes. Each is a different chemical. They all have similar pain-relieving effects, but they have some important differences:

 
• Aspirin and ibuprofen reduce inflammation; acetaminophen does not.  
• Aspirin and ibuprofen are often used to reduce the pain of swollen joints and other inflamed areas; acetaminophen is not.  
• Aspirin and ibuprofen can irritate the stomach. Sometimes they even cause stomach bleeding. Acetaminophen does not have this effect.  
• Aspirin and ibuprofen can affect blood clotting and may cause bleeding. Acetaminophen has no effect on blood clotting.  
• When aspirin is used to treat children with viral diseases such as the flu or chickenpox, it may cause Reye’s syndrome, a rare brain and liver disease. Acetaminophen and ibuprofen do not cause Reye’s syndrome.  
• Ibuprofen can make existing kidney problems worse. In normal doses, aspirin and acetaminophen usually do not injure the kidneys.