Letairis

Letairis is a prescription medication used to treat high blood pressure in the arteries of the lungs, known medically as pulmonary arterial hypertension (PAH). Letairis belongs to a group of drugs called endothelin receptor antagonists. It works by stopping the action of a natural substance that causes blood vessels to narrow in people who have PAH.

This medication comes in tablet form and is usually taken once a day, with or without food. Swallow tablets whole.

Common side effects of Letairis include swelling of hands, legs, and feet, stuffy nose, and hot flashes.

Letairis is a prescription medicine to treat pulmonary arterial hypertension (PAH), which is high blood pressure in the arteries of the lungs.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

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Serious side effects of Letairis include:

• Serious birth defects. (See "Drug Precautions").
• Swelling all over the body (fluid retention) can happen within weeks after starting Letairis. Tell your doctor right away if you have any unusual weight gain, tiredness, or trouble breathing while taking Letairis. These may be symptoms of a serious health problem. You may need to be treated with medicine or need to go to the hospital.
• Sperm count reduction. Reduced sperm counts have been observed in some men taking a drug similar to Letairis, an effect which might impair their ability to father a child. Tell your doctor if remaining fertile is important to you.
• Low red blood cell levels (anemia) can happen during the first weeks after starting Letairis. If this happens, you may need a blood transfusion. Your doctor will do blood tests to check your red blood cells before starting Letairis. Your doctor may also do these tests during treatment with Letairis.

The most common side effects of Letairis are:

• Swelling of hands, legs, ankles and feet (peripheral edema)
• Stuffy nose (nasal congestion)
• Inflamed nasal passages (sinusitis)
• Hot flashes or getting red in the face (flushing)

Other side effects of Letairis include:

• loss of strength or energy, weakness
• dizziness
• tiredness

Some medicines that are like Letairis can cause liver problems. Tell your doctor if you get any of these symptoms of a liver problem while taking Letairis:

• loss of appetite
• nausea or vomiting
• fever
• achiness
• generally do not feel well
• pain in the upper right stomach (abdominal) area
• yellowing of your skin or the whites of your eyes
• dark urine
• itching

Tell your doctor if you have any side effect that bothers you or that does not go away. These are not all of the possible side effects of Letairis. For more information, ask your doctor or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your medical conditions and all the medicines you take including prescription and nonprescription medicines. Letairis and other medicines may affect each other causing side effects. Do not start any new medicines until you check with your doctor.

Especially tell your doctor if you take the medicine cyclosporine (Gengraf, Neoral, Sandimmune). Your doctor may need to change your dose of Letairis. You should not take more than 5 mg of Letairis each day if you also take cyclosporine.

The most important information you should know about Letairis:

• Serious birth defects.
  Letairis can cause serious birth defects if taken during pregnancy.
  • Women must not be pregnant when they start taking Letairis or become pregnant during treatment.
  • Women who are able to get pregnant must have a negative pregnancy test before beginning treatment with Letairis and each month during treatment. Your doctor will decide when to do the test, depending on your menstrual cycle.
  Women who are able to get pregnant must use two acceptable forms of birth control, during Letairis treatment and for one month after stopping Letairis.
  • If you have had a tubal sterilization or have an IUD, these methods can be used alone and no other form of birth control is needed.
  • Talk with your doctor or gynecologist (a doctor who specializes in female reproduction) to find out about how to prevent pregnancy.
  • Do not have unprotected sex. Talk to your doctor or pharmacist right away if you have unprotected sex or if you think your birth control has failed. Your doctor may tell you to use emergency birth control.
  • Tell your doctor right away if you miss a menstrual period or think you may be pregnant.

Letairis is available only through a restricted program. To receive Letairis, you must talk to your doctor, understand the benefits and risks of Letairis, and agree to all of the instructions in the program.

Do not take Letairis if:

• you are pregnant, plan to become pregnant, or become pregnant during treatment with Letairis. Letairis can cause serious birth defects. Serious birth defects from Letairis happen early in pregnancy.
• you have a condition called Idiopathic Pulmonary Fibrosis (IPF).

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Letairis, there are no specific foods that you must exclude from your diet when receiving this medication.

Before taking Letairis, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to Letairis or to any of its ingredients
• are pregnant, plan to become pregnant, or become pregnant during treatment
• breastfeeding

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

This medication falls into category X. Do not take ambrisentan if you are pregnant, plan to become pregnant, or become pregnant during treatment with Letairis. Letairis can cause serious birth defects. Serious birth defects from Letairis happen early in pregnancy.

Breastfeeding is not recommended while taking Letairis. It is not known if Letairis can pass through your milk and harm your baby.

Letairis will be mailed to you by a specialty pharmacy. Your doctor will give you complete details.

• Take Letairis exactly as your doctor tells you. Do not stop taking Letairis unless your doctor tells you.
• You can take Letairis with or without food.
• Do not split, crush or chew Letairis tablets.
• It will be easier to remember to take Letairis if you take it at the same time each day.
• If you take more than your regular dose of Letairis, call your doctor right away.
• If you miss a dose, take it as soon as you remember that day. Take your next dose at the regular time. Do not take two doses at the same time to make up for a missed dose.

What you should avoid while taking Letairis:

• Do not get pregnant while taking Letairis. If you miss a menstrual period, or think you might be pregnant, call your doctor right away.
• Breastfeeding is not recommended while taking Letairis. It is not known if Letairis can pass through your milk and harm your baby.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• the condition being treated
• other medications you are taking
• how you respond to this medication

The recommended dose range of Letairis is 5mg-10mg/day.

You should not take more than 5 mg of Letairis each day if you also take cyclosporine.

If you take too much Letairis, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

If Letairis is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

• Store Letairis at 59 °F to 86 °F (15 °C to 30 °C), in the package it comes in.
• Keep Letairis and all medicines out of the reach of children.

WARNING: CONTRAINDICATED IN PREGNANCY

Do not administer this medication to a pregnant woman because it may cause fetal harm. Letairis is very likely to produce serious birth defects if used by pregnant women, as this effect has been seen consistently when it is administered to animals.

Pregnancy must therefore be excluded before the initiation of treatment with Letairis and prevented during treatment and for one month after stopping treatment by the use of two acceptable methods of contraception unless the patient has had a tubal sterilization or chooses to use a Copper T 380A IUD or LNg 20 IUS, in which case no additional contraception is needed. Obtain monthly pregnancy tests.

Because of the risk of birth defects, Letairis is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS). As a component of the program, prescribers, patients, and pharmacies must enroll in the program.