Volibris (Ambrisentan) belongs to the group of medications called endothelin receptor antagonists. These medications block the action of endothelin in the arteries of the lung that causes blood vessels to tighten or constrict. Volibris (Ambrisentan) is used to treat the symptoms of primary pulmonary arterial hypertension (PAH), or high blood pressure in the arteries of the lungs.

It is also used to treat pulmonary hypertension resulting from connective tissue diseases such as Arthritis that have not adequately responded to other therapies for pulmonary hypertension.

Volibris (Ambrisentan) may be available under multiple brand names and/or in several different forms. Any specific brand name of Volibris (Ambrisentan) may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of Volibris (Ambrisentan) may not be used for all of the conditions discussed here.

Your doctor may have suggested Volibris (Ambrisentan) for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking Volibris (Ambrisentan), speak to your doctor. Do not stop taking Volibris (Ambrisentan) without consulting your doctor.

Do not give Volibris (Ambrisentan) to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take Volibris (Ambrisentan) if their doctor has not prescribed it.

The usual adult starting dose is 5 mg taken once daily. If tolerated, the dose can be increased to the maximum dose of 10 mg taken once daily. Volibris (Ambrisentan) can be taken with or without food. Swallow the tablets whole. Do not split, crush, or chew the tablets.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take Volibris (Ambrisentan) exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store Volibris (Ambrisentan) at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Volibris (Ambrisentan). If you are concerned about side effects, discuss the risks and benefits of Volibris (Ambrisentan) with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• appetite changes
• bruising
• Constipation
• cough
• Diarrhea
• difficulty sleeping
• dizziness
• flushing
• frequent urination at night
• headache
• inflammation of the throat and nasal passages
• loss of appetite
• muscle pain
• nasal congestion
• nausea
• runny nose
• skin rash
• swelling of hands, feet, ankles, and legs
• tiredness or weakness
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

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

• chest pain
• dizziness or fainting
• Fever
• fluid retention, bloating
• nausea
• palpitations (irregular or rapid heartbeat that you can feel)
• ringing in the ears
• severe abdominal pain
• signs of Anemia (low red blood cells; e.g., dizziness,  pale skin, unusual tiredness or weakness, shortness of breath)
• signs of heart failure (e.g., shortness of breath, extreme tiredness, swelling in the ankles and legs)
• symptoms of pneumonia (e.g., fever or chills, shortness of breath, fatigue, chest pain, cough)
• vision changes or blurred vision
• worsening shortness of breath

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of an allergic reaction, e.g.:
• difficulty breathing
• Hives
• rash
• swelling of the face or throat
• symptoms of liver problems, e.g.:
• yellowing of the skin or eyes (jaundice)
• abdominal pain
• fever
• severe nausea
• vomiting

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Volibris (Ambrisentan).

5 mg tablet
Each square, pale pink, film-coated tablet engraved with "GS" on one side and "K2C" on the other contains 5 mg of Volibris (Ambrisentan). Nonmedicinal ingredients: microcrystalline cellulose, lactose monohydrate, croscarmellose sodium, magnesium stearate, polyvinyl alcohol, talc, titanium dioxide and macrogol/polyethylene glycol 3350, lecithin, and FD&C Red No. 40 Aluminium Lake.

10 mg tablet
Each oval, deep pink, film-coated tablet engraved with "GS" on one side and "KE3" on the other contains 10 mg of Volibris (Ambrisentan). Nonmedicinal ingredients: microcrystalline cellulose, lactose monohydrate, croscarmellose sodium, magnesium stearate, polyvinyl alcohol, talc, titanium dioxide and macrogol/polyethylene glycol 3350, lecithin, and FD&C Red No. 40 Aluminium Lake.

Do not take Volibris (Ambrisentan) if you:

• are allergic to Volibris (Ambrisentan) or to any of the ingredients of the medication
• are pregnant or plan on becoming pregnant
• are breast-feeding
• have a lung condition called idiopathic Pulmonary Fibrosis (thickening or scarring of the lungs that makes breathing difficult)
• have severely decreased liver function or abnormal liver test results

There may be an interaction between Volibris (Ambrisentan) and any of the following:

• birth control pills
• Cyclosporine A
• Digoxin
• ketoconazole and other "azole" antifungal medications
• Omeprazole
• rifampin
• Sildenafil and other Erectile Dysfunction drugs (Tadalafil, Vardenafil)
• Warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Volibris (Ambrisentan). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Volibris (Ambrisentan).

Blood changes: Volibris (Ambrisentan) may decrease hemoglobin levels and cause anemia (not enough red blood cells in your blood). Hemoglobin is the protein in red blood cells that carries oxygen throughout your body. Your doctor will perform regular tests to monitor your blood for changes while you are taking Volibris (Ambrisentan). People who have anemia should talk to their doctor before taking Volibris (Ambrisentan). If you experience symptoms of anemia such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.

Fluid retention: Fluid buildup in the body can occur as a result of pulmonary arterial hypertension (PAH), but it can also be caused by Volibris (Ambrisentan). This swelling is usually mild to moderate. However, tell your doctor if you experience symptoms of severe, increased swelling of your hands, feet, ankles, and legs while taking Volibris (Ambrisentan).

Liver function: This medication may cause liver damage. Your doctor will monitor your liver function by performing regular liver function tests while you are taking Volibris (Ambrisentan). Be sure to tell your doctor if you experience any signs of liver problems, such as yellowing of the skin or whites of the eyes, abdominal pain, or dark urine. If you have liver disease, discuss with your doctor how Volibris (Ambrisentan) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Volibris (Ambrisentan), and whether any special monitoring is needed.

Pregnancy: Volibris (Ambrisentan) should not be used in pregnancy. Taking Volibris (Ambrisentan) during pregnancy can cause serious birth defects. Women who may become pregnant must not take Volibris (Ambrisentan) until pregnancy is excluded. A pregnancy test must be performed before starting treatment with Volibris (Ambrisentan). A reliable form of birth control must be used at the same time during treatment with Volibris (Ambrisentan). Regularly pregnancy tests should be performed throughout treatment with Volibris (Ambrisentan). If you become pregnant while taking Volibris (Ambrisentan), contact your doctor immediately.

Breast-feeding: It is not known if Volibris (Ambrisentan) passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of Volibris (Ambrisentan) have not been established for children or adolescents under 18 years of age.

Seniors: People over the age of 65 are more likely to experience swelling of the hands, ankles, and feet while taking Volibris (Ambrisentan). Talk to your doctor if you have any concerns.