Tretinoin and Isotretinoin

Tretinoin and isotretinoin are the sound-alike generic names for two different medications. Both are used to treat acne and both belong to a group of medications called retinoids. Retinoids are medications that are derived from vitamin A.

This explains why the two drugs have such similar names. However, they are very different products. Here's what's important to know about each.

Tretinoin is the active ingredient in medications prescribed to treat mild to moderate pimples and blackheads. Some easily recognizable brand names for drugs containing tretinoin include Retin-A and Retin-A Micro.

These medications are used topically—meaning they come as a cream, ointment, or gel that can be applied directly to the skin, typically once or twice a day. Tretinoin helps to clear acne by speeding up the rate at which skin cells turn over (die and regenerate). This helps to unclog pores, clearing blackheads and inflamed pimples. 

Tretinoin can be used after acne has cleared up to prevent future breakouts. The typical side effects of tretinoin include dry skin, peeling, and redness. It hasn't been studied extensively in pregnant women, though, so a woman who's expecting should not use it. 

Isotretinoin is an oral medication, meaning it comes as a pill that you swallow. It's prescribed for severe forms of acne or for milder cases that aren't severe but are stubborn and not responding to other types of acne medication. Until 2009, isotretinoin was available in the United States by the brand name Accutane.

Isotretinoin medications are still prescribed, but they come with considerable side effects, some of which are potentially serious. The drug can cause skin, as well as eyes and lips. to become extremely dry, for example.

More worrisome, isotretinoin has been found to cause severe birth defects, including abnormalities of the face, eyes, ears, skull, central nervous system, cardiovascular system, and thymus and parathyroid glands. The drug also increases the risk of miscarriage and premature birth.

In fact, isotretinoin can be so devastating to a pregnancy or baby that anyone who takes the drug must first register with a program called iPledge Program. The requirements include using two methods of contraception or practicing complete abstinence during treatment, having negative pregnancy tests each month (for women of childbearing potential), seeing a doctor monthly, and submitting to regular blood tests as needed.

Unlike most acne medications, isotretinoin is only used for a finite length of time. Most people only need one or two courses in their lifetime. This can be great news though, becuase when it works, it essentially means acne has been cured.