• If you are allergic to anything, including medicines, dyes, additives, or foods.

• If you have any medical conditions such as kidney disease, liver disease (including hepatitis), heart disease, congestive heart failure, diabetes, gout, or infections. These conditions may require that your medicine dose, regimen, or timing be changed.

• If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. This drug may cause birth defects if either the male or female is taking it at the time of conception or during pregnancy. Men and women who are taking this drug need to use some kind of birth control during treatment and for a month after treatment is done. It is important to check with your doctor about what kinds of birth control can be used with this medicine.

• If you are breast-feeding. The drug may pass into breast milk and harm the baby. Breast feeding is not recommended while you are taking tretinoin.

• If you have had blood clots or stroke. Rarely, this drug can cause blood clots in the leg or arm, the lungs, brain (stroke), or other organs.

• About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs.

Vitamin A supplements from animal sources (such as fish liver oil) can cause toxic levels of Vitamin A in the body when taken during treatment with tretinoin. Vitamin A precursors from vegetable sources (such as beta carotene) are not a problem.

Any medicine that is taken to stop bleeding may increase your risk of serious blood clots.

Birth control pills with small doses of progesterone (the "mini-pill") may not work when you are taking tretinoin.

Check with your doctor, nurse, or pharmacist about other medicines, vitamins, herbs, and supplements, and whether alcohol can cause problems with this medicine.

Your doctor will likely test your blood throughout your treatment, looking for possible effects of the drug on blood counts (described below) or on other body organs. Based on the test results, you may be given medicines to help treat any effects. Your doctor may also need to reduce or delay your next dose of this drug, or even stop it altogether.

This drug can increase your chance of getting an infection. Be sure to let your doctor or nurse know right away if you have any signs of infection, such as fever (100.5° or higher), shaking chills, pain when passing urine, a new cough, or bringing up sputum.

This drug may increase your risk of bleeding. Speak with your doctor before taking any drugs or supplements that might affect your body's ability to stop bleeding, such as aspirin or aspirin-containing medicines, warfarin (Coumadin), or vitamin E. Tell your doctor right away if you have unusual bruising, or bleeding such as nosebleeds, bleeding gums when you brush your teeth, or black, tarry stools.

This drug may cause blood clots. They may form in the leg or arm (deep vein thrombosis), and cause stroke, or a blockage in the lungs or other organs. Call your doctor or nurse right away if you develop pain in your lower leg (calf), redness or swelling of your arm or leg, shortness of breath, chest pain, or trouble speaking or moving.

Tretinoin may cause sores in the mouth or on the lips, which often occur within the first few weeks after starting treatment. This can cause mouth pain, bleeding, or even trouble eating. Your doctor or nurse can suggest ways to reduce this, such as changing the way you eat or how you brush your teeth. If needed, your doctor can prescribe medicine to help with the pain.

This drug may cause hair loss. You may want to talk to your doctor or nurse about getting a wig before starting treatment. If your insurance does not cover it, there may be other resources to help you. Hair loss is usually temporary, and your hair will likely grow back during or after treatment.

Tretinoin can cause severe liver damage in a few people. Your doctor will likely check your blood so that if this happens, it can be found early. Call your doctor right away if you notice nausea, vomiting, fatigue, poor appetite, dark urine, yellowing skin or eyes, or tenderness under the right side of the rib cage.

Do not get any immunizations (vaccinations), either during or after treatment with this drug, without your doctor's OK. This drug may affect your immune system, which could make vaccinations ineffective, or could even lead to serious infections. Try to avoid contact with people who have recently received a live virus vaccine, such as the oral polio vaccine or smallpox vaccine. Check with your doctor about this.

Tell your doctor or nurse right away if you develop fever, trouble breathing, weight gain, swelling, or irregular heart beat. This can be a serious complication and must be treated right away.

Vitamin A toxicity may occur (from getting too much Vitamin A). The symptoms include headache, usually starting the first week of treatment and then fading, along with fever, dry mouth and skin, bone pain, nausea, vomiting, rash, sores in the mouth, hair loss, and changes in vision. Report any of these to your doctor or nurse right away. Tell your doctor if you are taking any vitamin A products (see drug interactions section, above).

It is important to continue taking this drug, even if you feel well. If you have side effects, talk to your doctor or nurse find out whether the problems are serious and how you can lessen them.

If you have hallucinations (seeing, hearing, or feeling things that aren't there) confusion, or seizures, get help right away.

• headache*
• fever*
• dry mouth
• bone pain
• nausea*
• vomiting*
• rash
• poor appetite

• dizziness*
• feeling of pins and needles in hands and feet
• earache
• depression
• heartburn
• swollen belly*
• weight loss
• constipation, diarrhea
• syndrome of fever, trouble breathing, weight gain, changes in chest x-ray, and fluid outside the lungs or heart*
• sores in mouth or on lips*
• itching
• sweating
• changes in vision*
• skin changes
• irregular heartbeat*
• changes in blood pressure
• flushing

• heart damage
• ulcer
• abnormal blood tests which suggest that the drug is affecting the liver (Your doctor will discuss the importance of this finding, if any.)
• thinning hair
• decreased hearing
• agitation
• hallucinations*
• seizures*
• sleepiness*
• slow speech
• trouble urinating
• high triglyceride and cholesterol levels (lipids) in the blood
• weakness
• bleeding*
• blood clots, including stroke or heart attack*
• birth defects if taken during pregnancy, or if pregnancy occurs within a month after taking the drug

*See the "Precautions" section for more detailed information.