Isentress

Isentress is a prescription medication used to treat human immunodeficiency virus (HIV) infection in combination with other anti-HIV medicines. Isentress belongs to a group of drugs called integrase inhibitors. This medication works by blocking the activity of a substance in the virus (HIV) called HIV integrase which is required to make more viruses.

This medication comes in tablets, chewable tablets, and powder for suspension. This medication is taken once a day or twice a day, with or without food.

Common side effects of Isentress include nausea, headache, tiredness, weakness, and trouble sleeping.

Isentress is an anti-HIV (antiretroviral) medicine used for the treatment of human immunodeficiency virus (HIV), the virus that causes AIDS (Acquired Immune Deficiency Syndrome), in adults and children weighing at least 4.4 lbs (2 kg). Isentress is used along with other anti-HIV medicines. Isentress will NOT cure HIV infection, however.

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

• Merck Sharp & Dohme Corp.

When Isentress has been given with other anti-HIV drugs, side effects included:

• nausea
• headache
• tiredness
• weakness
• trouble sleeping
• stomach pain
• dizziness
• depression
• suicidal thoughts and actions

Other side effects include: rash, severe skin reactions, feeling anxious, paranoia, low blood platelet count, diarrhea, liver failure.

A condition called Immune Reconstitution Syndrome can happen in some patients with advanced HIV infection (AIDS) when combination antiretroviral treatment is started. Signs and symptoms of inflammation from opportunistic infections that a person has or had may occur as the medicines work to treat the HIV infection and help to strengthen the immune system. Call your doctor right away if you notice any signs or symptoms of an infection after starting Isentress with other anti-HIV medicines.

Contact your doctor promptly if you experience unexplained muscle pain, tenderness, or weakness while taking Isentress. This is because on rare occasions, muscle problems can be serious and can lead to kidney damage.

Rash occurred more often in patients taking Isentress and darunavir together than with either drug separately, but was generally mild.

Tell your doctor if you have any side effects that bother you.

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

• rifampin (Rifadin, Rifamate, Rifater, Rimactane), a medicine commonly used to treat tuberculosis.
• atazanavir (Reyatz)
• efavirenz (Sustiva)
• etravirine (Intelence)
• cimetidine (Tagamet)
• famotidine (Pepcid)
• nizatidine (Axid)
• ranitidine (Zantac)
• phenobarbital
• phenytoin (Dilantin)
• dexlansoprazole (Dexilant)
• esomeprazole (Nexium)
• lansoprazole (Prevacid)
• omeprazole (Prilosec)
• pantoprazole (Protonix)
• rabeprazole (Aciphex)
• boceprevir
• telaprevir
• antacids containing aluminum and/or magnesium

This is not a complete list of all possible drug interactions with Isentress. Talk with your doctor or pharmacist for a complete list.

Serious side effects can occur including:

• Severe and life-threatening skin reactions and allergic reactions have been reported in some patients taking Isentress. If you develop a rash with fever, extreme tiredness, muscle or joint aches, blisters or sores in your mouth, redness of the eyes, and breathing problems, call your doctor right away.
• Liver problems may be caused by an allergic reaction. Call your doctor right away if you have symptoms of liver problems including: yellowing of the skin or whites of the eyes, dark urine, nausea or vomiting, loss of appetite, and pain or tenderness on the right side below the ribs.
• Serious muscle problem. Tell your doctor right away if you get unexplained muscle pain, tenderness, or weakness while taking Isentress. This may be a sign of a rare but serious muscle problem that can lead to kidney problems.

Isentress does not reduce the chance of passing HIV to others through sexual contact, sharing needles, or being exposed to your blood.

• Continue to practice safer sex.
• Use latex or polyurethane condoms or other barrier methods to lower the chance of sexual contact with any body fluids. This includes semen from a man, vaginal secretions from a woman, or blood.
• Never re-use or share needles.
• Ask your doctor if you have any questions about safer sex or how to prevent passing HIV to other people.

Isentress chewable tablets contain phenylalanine. This may be harmful to people with phenylketonuria (PKU).

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if Isentress will harm your unborn baby.

Do not breastfeed while taking Isentress. You should not breastfeed if you have HIV because of the risk of passing HIV to your baby.

Medicines 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 Isentress there are no specific foods that you must exclude from your diet when receiving Isentress.

Tell your doctor about all of your medical conditions. Include any of the following that applies to you:

• You have any allergies.
• You are pregnant or plan to become pregnant.
• Isentress is not recommended for use during pregnancy. Isentress has not been studied in pregnant women. If you take Isentress while you are pregnant, talk to your doctor about how you can be included in the Antiretroviral Pregnancy Registry.
• You are breast-feeding or plan to breast-feed.
• It is recommended that HIV-infected women should not breast-feed their infants. This is because their babies could be infected with HIV through their breast milk.

Talk with your doctor about the best way to feed your baby. Tell your doctor about all the medicines you take. Include the following:

• prescription medicines, including rifampin (a medicine used to treat some infections such as tuberculosis)
• non-prescription medicines
• vitamins
• herbal supplements
• antacids containing aluminum and/or magnesium. Taking aluminum and/or magnesium hydroxide-containing antacids and Isentress is not recommended.

Keep a list of your medicines. Show the list to your doctor and pharmacist when you get a new medicine.

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if Isentress will harm your unborn baby.

Do not breastfeed while taking Isentress. You should not breastfeed if you have HIV because of the risk of passing HIV to your baby.

Take Isentress exactly as your doctor has prescribed. The recommended dose is as follows:

This medication can be taken once or twice a day. 

• Take it by mouth.
• Take it with or without food.
• Do not change your dose or stop taking Isentress or your other anti-HIV medicines without first talking with your doctor.

IMPORTANT: Take Isentress exactly as your doctor prescribed and at the right times of day because if you don't:

• The amount of virus (HIV) in your blood may increase if the medicine is stopped for even a short period of time.
• The virus may develop resistance to Isentress and become harder to treat.
• Your medicines may stop working to fight HIV.
• The activity of Isentress may be reduced (due to resistance).

If you fail to take Isentress the way you should, here's what to do:

• If you miss a dose, take it as soon as you remember. If you do not remember until it is time for your next dose, skip the missed dose and go back to your regular schedule. Do NOT take two tablets of Isentress at the same time. In other words, do NOT take a double dose.
• If you take too much Isentress, call your doctor or local Poison Control Center.
• Be sure to keep a supply of your anti-HIV medicines.
• When your Isentress supply starts to run low, get more from your doctor or pharmacy.
• Do not wait until your medicine runs out to get more.

Take Isentress exactly as prescribed by your doctor. Follow the directions on your prescription label carefully. Your doctor will determine the best dose for you.

Isentress can be taken with or without food.

Do not substitute Isentress chewable tablets or Isentress for oral suspension for the Isentress film-coated tablets. 

Adults

For those who have never been on treatment and for those whose virus is under controlled with Isentress 400 mg twice daily:

• 1200 mg (2 x 600 mg) film-coated tablet orally, once daily or 400 mg film-coated tablet orally, twice daily

For those already being treated for HIV:

• 400 mg film-coated tablet orally, twice daily
• During coadministration with rifampin in adults, Isentress 800 mg twice daily is recommended. 

Pediatrics

For children who weigh at least 40 kg, have never been on treatment, or for those whose virus is controlled with Isentress 400 mg twice daily:

• 1200 mg (2 x 600 mg) film-coated tablet orally, once daily or 400 mg film-coated tablet orally, twice daily or 300 mg chewable tablets, twice daily

For children who weigh at least 25 kg: One 400 mg film-coated tablet orally, twice daily.

• If unable to swallow a tablet, consider the chewable tablet. The dosing recommendation for the chewable tablet is based on approximately 6 mg/kg/dose twice daily. 

For children (at least 4 weeks [28 days] of age) weighing at least 6.6 lbs (3 kg) to less than 55 lbs (25 kg):

• Consider the chewable tablet or oral suspension. The dosing recommendation for the chewable tablet or oral suspension is based on approximately 6 mg/kg/dose twice daily. 

For children (birth to 4 weeks [28 days] of age) weighing at least 4.4 lbs (2 kg):

• The dosing recommendation for the oral suspension is based on approximately 1.5 mg/kg/dose to 3 mg/kg/dose once or twice daily. 

Do not change your dose or stop taking Isentress or your other anti-HIV medicines without first talking with your doctor.

If you have taken too much Isentress (more than your doctor prescribed) call your doctor or local Poison Control Center right away.

Store Isentress at room temperature (68 to 77°F).

Keep Isentress and all medicines out of the reach of children.