Raltegravir belongs to the class of medications called antiretrovirals. It is used in combination with other antiretroviral medications to treat HIV infection in adults and in children at least 2 years of age, weighing at least 7 kg.

It works by blocking an enzyme, HIV integrase, which the virus needs to make more virus. When used with other antiretroviral medications, raltegravir helps the immune system by reducing the amount of HIV in the blood and increasing the number of CD4 or T-cells.

This medication does not cure HIV infection or AIDS and does not reduce the risk of passing HIV to others through sexual contact or blood contamination.

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

Your doctor may have suggested this medication 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 this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

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

The usual dose of raltegravir for adolescents and adults is one 400 mg tablet, taken by mouth, 2 times daily or two 600 mg tablets taken once daily. The dose of chewable tablets for children more than 2 years old but less than 12 years of age is based on the child's body weight. Do not switch between the 400 mg tablets, 600 mg tablets, or the chewable tablets without checking with your doctor first.

Raltegravir may be taken with or without food.

Many things can affect the dose of a 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 this medication exactly as prescribed by your doctor. The amount of HIV virus in your blood can increase if this medication is stopped for even a short period of time. Taking this medication exactly as prescribed will also decrease the chance of drug resistance (i.e., the medication stops working to fight HIV).

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 this medication in its original package at room temperature and keep it out of the reach of children. Keep the desiccant in the bottle to protect it from moisture.

Chewable tablet

25 mg
Each pale yellow, round, flat-faced, bevelled-edge tablet debossed with the Merck logo on one side and "473" on the other contains 27.16 mg of raltegravir as potassium salt, equivalent to 25 mg of raltegravir. Nonmedicinal ingredients: ammonium hydroxide, crospovidone, ethylcellulose 20 cP, fructose, hydroxypropyl cellulose, hypromellose 2910/6cP, macrogol/PEG 400, magnesium stearate, mannitol, medium chain triglycerides, monoammonium glycyrrhizinate, natural and artificial flavors (orange, banana, and masking), oleic acid, phenylalanine (as part of the artificial sweetener, aspartame), saccharin sodium, sodium citrate dihydrate, sodium stearyl fumarate, sorbitol, sucralose, and yellow iron oxide.

100 mg
Each pale orange, oval, scored tablet debossed with the Merck logo on one side of the score and "477" on the other side of the tablet contains 108.6 mg of raltegravir as potassium salt, equivalent to 100 mg of raltegravir. Nonmedicinal ingredients: ammonium hydroxide, crospovidone, ethylcellulose 20 cP, fructose, hydroxypropyl cellulose, hypromellose 2910/6cP, macrogol/PEG 400, magnesium stearate, mannitol, medium chain triglycerides, monoammonium glycyrrhizinate, natural and artificial flavors (orange, banana, and masking), oleic acid, phenylalanine (as part of the artificial sweetener, aspartame), saccharin sodium, sodium citrate dihydrate, sodium stearyl fumarate, sorbitol, sucralose, yellow iron oxide, and red iron oxide.

Tablet

400 mg
Each pink, oval, film-coated tablet marked with "227" on one side contains 434.4 mg of raltegravir potassium as salt, equivalent to 400 mg of raltegravir. Nonmedicinal ingredients: microcrystalline cellulose, lactose monohydrate, calcium phosphate dibasic anhydrous, hypromellose 2208, poloaxamer 407 (contains butylated hydroxytoluene as antioxidant), sodium stearyl fumarate, magnesium stearate; film-coating: polyvinyl alcohol, titanium dioxide, polyethylene glycol 3350, talc, red iron oxide, and black iron oxide.

600 mg
Each yellow, oval, film-coated tablet, debossed with Merck logo and "242" on one side, contains 651.6 mg of raltegravir potassium as salt, equivalent to 600 mg of raltegravir. Nonmedicinal ingredients: croscarmellose sodium, hypromellose 2910, magnesium stearate, microcrystalline cellulose; film coating: black iron oxide, carnauba wax, hypromellose 2910, iron oxide yellow, lactose monohydrate, titanium dioxide, and triacetin.

Do not take raltegravir if you are allergic to raltegravir or to any of the ingredients of the medication.

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 this medication. If you are concerned about side effects, discuss the risks and benefits of this medication 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
• back pain
• cold-like symptoms (e.g., runny nose, nasal congestion, sore throat)
• cough
• diarrhea
• difficulty sleeping
• dizziness
• fatigue
• fever
• headache
• heartburn
• nasal and throat irritation
• nausea
• rash
• shaking
• vomiting

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

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

• decreased coordination
• decreased concentration
• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of infection (e.g., fever, chills, sore throat, mouth ulcers, cough)
• signs of kidney problems (e.g., nausea, loss of appetite, weakness, passing little or no urine, shortness of breath)
• signs of liver problems (e.g., nausea, vomiting, loss of appetite, feeling unwell, fever, itching, yellowing of the skin or whites of eyes, dark urine)
• speech difficulties
• unexplained muscle weakness, tenderness, or pain

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

• severe chest pain
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a severe skin reaction (e.g., blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort)

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 this medication.

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 take this medication.

Hypersensitivity syndrome: A severe allergic reaction called hypersensitivity syndrome has occurred for some people with the use of raltegravir. This reaction involves a number of organs in the body and may be fatal if not treated quickly. Stop taking the medication and get immediate medical attention if you have symptoms of a severe allergic reaction, including fever, swollen glands, yellowing of the skin or eyes, or flu-like symptoms with skin rash or blistering.

Immune reconstitution inflammatory syndrome: This medication may cause immune reconstitution inflammatory syndrome, where signs and symptoms of inflammation from previous infections appear. These symptoms occur soon after starting anti-HIV medication and can vary. They are thought to occur as a result of the immune system improving and being able to fight infections (e.g., pneumonia, herpes, or tuberculosis) that have been present without symptoms. Report any new symptoms to your doctor immediately.

Muscle pain: Occasionally, raltegravir causes breakdown of muscle tissues, which can be fatal. Report any symptoms of severe, unexplained muscle pain to your doctor as soon as possible.

Phenylketonuria (PKU): People with phenylketonuria, a disorder where the body cannot break down the amino acid phenylalanine, should not use the chewable tablets. The artificial sweetener in the chewable tablets contains phenylalanine and will be harmful to someone with PKU.

Skin reactions: Raltegravir may cause skin rash or itchiness with or without a rash. On rare occasions, people taking raltegravir experience a severe skin reaction that can be life-threatening. If you experience a rash that gets worse, or develops into blisters or sores on the lips or eyes, or covers a large area of the body, contact your doctor immediately.

Pregnancy: There are no studies evaluating the use of this medication by pregnant women. This medication is not recommended during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if this medication passes into breast milk. However, breast-feeding is not recommended for HIV-positive women since the virus can be passed to the baby through breast milk.

Children: The safety and effectiveness of using this medication have not been established for children less than 2 years old. The safety and effectiveness of using the 600 mg tablets has not been established for children weighing less than 40 kg.

There may be an interaction between raltegravir and any of the following:

• aluminum hydroxide
• atazanavir
• bezafibrate
• calcium carbonate
• etravirine
• fenofibrate
• fosamprenavir
• gemfibrozil
• iron supplements (e.g., ferrous fumarate, ferrous gluconate, ferrous sulfate)
• magnesium salts (e.g., magnesium citrate, magnesium sulfate)
• multivitamin and mineral supplements
• orlistat
• phenobarbital
• phenytoin
• rifabutin
• rifampin
• selenium
• "statin" anti-cholesterol medications (e.g., atorvastatin, lovastatin, simvastatin)
• sucralfate
• tipranavir
• zidovudine
• zinc supplements (e.g., zinc gluconate, zinc sulfate)

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 this medication. 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.