During the first 3 weeks you are using tretinoin, your skin may become irritated. Also, your acne may seem to get worse before it gets better. It may take longer than 12 weeks before you notice full improvement of your acne, even if you use the medicine every day. Check with your health care professional at any time skin irritation becomes severe or if your acne does not improve within 8 to 12 weeks.

You should avoid washing the skin treated with tretinoin for at least 1 hour after applying it.

Avoid using any topical medicine on the same area within 1 hour before or after using tretinoin. Otherwise, tretinoin may not work properly or skin irritation might occur.

Unless your doctor tells you otherwise, it is especially important to avoid using the following skin products on the same area as tretinoin:

• Any other topical acne product or skin product containing a peeling agent (such as benzoyl peroxide, resorcinol, salicylic acid, or sulfur)
• Hair products that are irritating, such as permanents or hair removal products
• Skin products that cause sensitivity to the sun, such as those containing spices or limes
• Skin products containing a large amount of alcohol, such as astringents, shaving creams, or after-shave lotions
• Skin products that are too drying or abrasive, such as some cosmetics, soaps, or skin cleansers

Using these products along with tretinoin may cause mild to severe irritation of the skin. Although skin irritation can occur, some doctors sometimes allow benzoyl peroxide to be used with tretinoin to treat acne. Usually tretinoin is applied at night so that it does not cause a problem with any other topical products that you might use during the day. Check with your doctor before using topical medicines with tretinoin.

During the first 6 months of use, avoid overexposing the treated areas to sunlight, wind, or cold weather. The skin will be more prone to sunburn, dryness, or irritation, especially during the first 2 or 3 weeks. However, you should not stop using RETIN-A unless the skin irritation becomes too severe. Do not use a sunlamp .

To help tretinoin work properly, regularly use sunscreen or sunblocking lotions with a sun protection factor (SPF) of at least 15. Also, wear protective clothing and hats, and apply creams, lotions, or moisturizers often.

Check with your doctor at any time your skin becomes too dry and irritated. Your health care professional can help you choose the right skin products for you to reduce skin dryness and irritation and may include the following:

• For patients using tretinoin for the treatment of acne:
  • Regular use of water-based creams or lotions helps to reduce skin irritation or dryness that may be caused by the use of tretinoin.
• For patients using tretinoin for the treatment of fine wrinkling, dark spots, and rough skin caused by the sun:
  • RETIN-A should be used as part of an ongoing program to avoid further damage to your skin from the sun. This program includes staying out of the sun when possible or wearing proper clothing or hats to protect your skin from sunlight.
  • Regular use of oil-based creams or lotions helps to reduce skin irritation or dryness caused by the use of tretinoin.

In some animal studies, tretinoin has been shown to cause skin tumors to develop faster when the treated area is exposed to ultraviolet light (sunlight or artificial sunlight from a sunlamp). Other studies have not shown the same result and more studies need to be done. It is not known if tretinoin causes skin tumors to develop faster in humans.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Burning feeling or stinging skin (severe);  lightening of skin of treated area, unexpected;  peeling of skin (severe);  redness of skin (severe) ;  unusual dryness of skin (severe) 
  
  

• Rare
  • Darkening of treated skin 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Burning feeling, stinging, or tingling of skin (mild)—lasting for a short time after first applying the medicine;  chapping or slight peeling of skin (mild);  redness of skin (mild);  unusual dryness of skin (mild);  unusually warm skin (mild) 
  
  

The side effects will go away after you stop using tretinoin. On the rare chance that your skin color changes, this effect may last for several months before your skin color returns to normal.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although this use is not included in product labeling, tretinoin is used in certain patients with the following medical conditions:

• Keratosis follicularis (skin disorder of small, red bumps)
• Verruca plana (flat warts)

Other than the above information, there is no additional information relating to its proper use, precautions, or side effects for these uses.