Nevirapine

What Nevirapine is and what it is used for

This medicine belongs to a group of medications called antiretrovirals, which are used to treat Human Immunodeficiency Virus (HIV-1) infection. In Canada, it may be prescribed as part of HIV care under the guidance of a healthcare professional.

The active ingredient in this medicine is nevirapine. It helps reduce the amount of virus in the blood, which can help improve your condition. It belongs to a group of anti-HIV medicines called non-nucleoside reverse transcriptase inhibitors (NNRTIs). Reverse transcriptase is an enzyme HIV needs to multiply. This medicine blocks that enzyme. By stopping reverse transcriptase from working, it helps control HIV-1 infection.

You must take this medicine together with other antiretroviral medicines. Your doctor will recommend the best medicines for you.

Before you take this medicine

Do not take this medicine

• if you are allergic (hypersensitive) to nevirapine or any of the other ingredients in this medicine. See Section 6 of this leaflet for a list of the other ingredients
• if you have taken this medicine before and had to stop treatment because you developed:
• a severe skin rash
• a skin rash with other symptoms, for example:
• fever
• blistering
• mouth sores
• inflammation of the eye
• swelling of the face
• general swelling
• shortness of breath
• muscle or joint pain
• a general feeling of being unwell
• abdominal pain
• hypersensitivity (allergic) reactions
• inflammation of the liver (hepatitis)
• if you have severe liver disease
• if you have had to stop treatment in the past because of changes in your liver function
• if you are taking a medicine containing the herbal ingredient St John's Wort (Hypericum perforatum). This herbal ingredient may stop this medicine from working properly.

Take special care: During the first 18 weeks of treatment, it is very important that you and your doctor watch for signs of liver or skin reactions. These can become severe and even life-threatening. You are at greatest risk during the first 6 weeks of treatment.

If you develop a severe rash or hypersensitivity (allergic reactions that may appear as a rash) together with other side effects such as

• fever,
• blistering,
• mouth sores,
• inflammation of the eye,
• swelling of the face,
• general swelling,
• shortness of breath,
• muscle or joint pain,
• a general feeling of being unwell,
• or abdominal pain

You should stop taking this medicine and contact your doctor right away, as these reactions can be life-threatening or lead to death. If you develop only a mild rash with no other symptoms, tell your doctor right away. They will advise you on whether you should stop taking the medicine.

If you develop symptoms that suggest liver damage, such as

• loss of appetite,
• feeling sick (nausea),
• vomiting,
• yellow skin (jaundice),
• abdominal pain

you should stop taking the medicine and contact your doctor right away.

If you develop severe liver, skin, or hypersensitivity reactions while taking this medicine, never take it again without speaking to your doctor. You must take the dose exactly as prescribed by your doctor. This is especially important during the first 14 days of treatment.

The following patients are at increased risk of developing liver problems:

• women
• people infected with hepatitis B or C
• people with abnormal liver function tests
• treatment-naive patients with higher CD4 cell counts at the start of therapy (women more than 250 cells/mm³, men more than 400 cells/mm³)
• pre-treated patients with detectable HIV-1 plasma viral load and higher CD4 cell counts at the start of therapy (women more than 250 cells/mm³, men more than 400 cells/mm³)

In some patients with advanced HIV infection (AIDS) and a history of opportunistic infection (an AIDS-defining illness), signs and symptoms of inflammation from previous infections may appear soon after anti-HIV treatment is started. These symptoms are thought to happen because the body's immune response improves, allowing the body to fight infections that may have been present without obvious symptoms. If you notice any symptoms of infection, tell your doctor right away.

Changes in body fat may happen in patients receiving combination antiretroviral therapy. Contact your doctor if you notice changes in body fat.

Some patients taking combination antiretroviral therapy may develop a bone condition called osteonecrosis (death of bone tissue caused by loss of blood supply to the bone). Length of combination antiretroviral therapy, corticosteroid use, alcohol use, severe weakening of the immune system, and a higher body mass index may be some of the many risk factors for developing this condition. Signs of osteonecrosis are joint stiffness, aches and pains (especially in the hip, knee, and shoulder), and difficulty moving. If you notice any of these symptoms, tell your doctor.

This medicine is not a cure for HIV infection. Because of this, you may continue to develop infections and other illnesses linked to HIV infection. You should therefore stay in regular contact with your doctor. In addition, this medicine does not prevent the risk of passing HIV to others through blood or sexual contact. Use appropriate precautions to help prevent passing HIV to other people. Please speak with your doctor.

Use in children

Tablets can be taken by:

• children 16 years of age or older
• children under 16 years of age who weigh 50 kg or more
• or children with a body surface area above 1.25 square metres.

For smaller children, an oral suspension is available.

Taking other medicines

Tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines, including medicines you got without a prescription. Tell your doctor about all other medicines you are taking before you start treatment. Your doctor may need to check whether your other medicines are still working and adjust the doses. Read the package leaflet for all other HIV medicines you are taking together with this medicine carefully.

It is particularly important that you tell your doctor if you are taking or have recently taken:

• St John's Wort (Hypericum perforatum, a medicine used to treat depression)
• rifampicin (a medicine used to treat tuberculosis)
• rifabutin (a medicine used to treat tuberculosis)
• macrolides, for example clarithromycin (medicines used to treat bacterial infections)
• fluconazole (a medicine used to treat fungal infections)
• ketoconazole (a medicine used to treat fungal infections)
• itraconazole (a medicine used to treat fungal infections)
• methadone (a medicine used to treat opioid dependence)
• warfarin (a medicine used to reduce blood clotting)
• hormonal contraceptives (for example, the "pill")
• atazanavir (another medicine used to treat HIV infection)
• lopinavir/ritonavir (another medicine used to treat HIV infection)
• fosamprenavir (another medicine used to treat HIV infection)
• efavirenz (another medicine used to treat HIV infection)

Your doctor will carefully monitor the effect of this medicine and any of these medicines if you are taking them together.

If you are on kidney dialysis, your doctor may consider adjusting your dose. This is because the active ingredient can be partly removed from your blood by dialysis.

Taking this medicine with food and drink

There are no restrictions on taking this medicine with food and drink.

Pregnancy and breast-feeding

Ask your doctor or pharmacist for advice before taking any medicine.

You should stop breast-feeding if you are taking this medicine. In general, it is recommended that you do not breast-feed if you have HIV infection because your baby could become infected with HIV through your breast milk.

Driving and using machines

There are no specific studies on the ability to drive and use machines. If you feel that your ability to drive or use machines may be affected, do not drive or use machines.

Important information about some of the ingredients

Tablets contain lactose (milk sugar). If your doctor has told you that you have an intolerance to some sugars, contact your doctor before taking this medicine.

How to take this medicine

You should not use this medicine on its own. You must take it with at least two other antiretroviral medicines. Your doctor will recommend the best medicines for you.

Always take this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure.

Take the tablets by mouth only. Do not chew them. You can take this medicine with or without food.

Dosage

The dose is one 200 mg tablet per day for the first 14 days of treatment (the "lead-in" period). After 14 days, the usual dose is one 200 mg tablet twice a day.

It is very important that you take only one tablet a day for the first 14 days (the "lead-in" period). If you develop any rash during this period, do not increase the dose. Instead, speak with your doctor.

The 14-day "lead-in" period has been shown to lower the risk of skin rash.

Because this medicine must always be taken together with other HIV antiretroviral medicines, follow the instructions for your other medicines carefully. These are provided in the package leaflets for those medicines.

This medicine is also available as a liquid oral suspension. This is particularly suitable if:

• you have problems swallowing tablets
• or you are a child weighing less than 50 kg
• or you are a child with a body surface area less than 1.25 square metres (your doctor will calculate your body surface area).

You should continue treatment for as long as your doctor tells you to.

Your doctor will monitor you with liver tests or check for side effects such as rash. Depending on the results, your doctor may decide to interrupt or stop treatment. Your doctor may then decide to restart you on a lower dose.

If you take more than you should

Do not take more than your doctor has prescribed or more than described in this leaflet. At present, there is only limited information on the effects of overdose. Contact your doctor if you have taken more than you should.

If you forget to take a dose

Try not to miss a dose. If you notice that you have missed a dose within 8 hours, take the next dose as soon as possible. If you notice it more than 8 hours later, take the next dose at the usual time.

If you stop taking this medicine

Taking all doses at the right times:

• greatly increases the effectiveness of your combination antiretroviral medicines
• reduces the chances of your HIV infection becoming resistant to your antiretroviral medicines.

It is important that you keep taking this medicine correctly, as described above, unless your doctor tells you to stop.

If you stop treatment for more than 7 days, your doctor will tell you to start the 14-day "lead-in" period (described above) again before returning to the twice-daily dose.

If you have any further questions about using this product, ask your doctor or pharmacist.

Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

The most important side effects are severe and life-threatening skin reactions and serious liver damage. These reactions occur mainly in the first 18 weeks of treatment. This is therefore an important period that requires close monitoring by your doctor.

If you notice any rash symptoms, tell your doctor right away.

When rash occurs, it is usually mild to moderate. However, in some patients, a rash that appears as a blistering skin reaction can be severe or life-threatening (Stevens-Johnson syndrome and toxic epidermal necrolysis), and deaths have been reported. Most cases of both severe rash and mild or moderate rash occur in the first 6 weeks of treatment.

If rash occurs and you also feel unwell, you must stop treatment and see your doctor right away.

Hypersensitivity (allergic) reactions can occur. These reactions may appear as anaphylaxis (a severe form of allergic reaction) with symptoms such as:

• rash
• swelling of the face
• difficulty breathing (bronchial spasm)
• anaphylactic shock

Hypersensitivity reactions can also occur as a rash with other side effects such as:

• fever
• blistering of the skin
• mouth sores
• inflammation of the eye
• swelling of the face
• general swelling
• shortness of breath
• muscle or joint pain
• a reduction in the number of white blood cells (granulocytopenia)
• a general feeling of being unwell
• severe problems with the liver or kidneys (liver or kidney failure)

Tell your doctor right away if you develop a rash and any of the other side effects of a hypersensitivity (allergic) reaction. Such reactions can be life-threatening.

Abnormal liver function has been reported with the use of this medicine. This includes some cases of inflammation of the liver (hepatitis), which can be sudden and severe (fulminant hepatitis), and liver failure, which can be fatal.

Tell your doctor if you develop any of the following symptoms of liver damage:

• loss of appetite
• feeling sick (nausea)
• vomiting
• yellow skin (jaundice)
• abdominal pain

Side effects are grouped according to how often they happen:

The side effects listed below have been reported in patients taking this medicine:

Very common:

• rash

Common:

• decreased number of white blood cells (granulocytopenia)
• allergic reactions (hypersensitivity)
• headache
• feeling sick (nausea)
• vomiting
• abdominal pain
• loose stools (diarrhea)
• inflammation of the liver (hepatitis)
• muscle pain (myalgia)
• feeling tired (fatigue)
• fever
• abnormal liver function tests

Uncommon:

• drug rash with systemic symptoms (drug rash with eosinophilia and systemic symptoms)
• allergic reaction characterized by rash, swelling of the face, difficulty breathing (bronchial spasm), or anaphylactic shock
• decreased number of red blood cells (anemia)
• yellow skin (jaundice)
• severe and life-threatening skin rashes (Stevens-Johnson syndrome/toxic epidermal necrolysis)
• hives (urticaria)
• fluid under the skin (angioedema)
• joint pain (arthralgia)

Rare:

• sudden and severe inflammation of the liver (fulminant hepatitis)

Combination antiretroviral therapy may cause changes in body shape due to changes in fat distribution. These may include loss of fat from the legs, arms, and face, increased fat in the abdomen (belly) and other internal organs, breast enlargement, and fatty lumps on the back of the neck ("buffalo hump"). The cause and long-term health effects of these conditions are not known at this time. Combination antiretroviral therapy may also cause increased lactic acid and sugar in the blood, hyperlipidemia (increased fats in the blood), and resistance to insulin.

The following events have also been reported when this medicine has been used in combination with other antiretroviral agents:

• decreased numbers of red blood cells or platelets
• inflammation of the pancreas
• decreased or abnormal skin sensation. These events are commonly associated with other antiretroviral agents and may be expected to occur when this medicine is used in combination with other agents; however, it is unlikely that these events are due to this treatment.

Use in children

A reduction in white blood cells (granulocytopenia) can occur, and this is more common in children. A reduction in red blood cells (anemia), which may be related to treatment, is also seen more often in children. As with rash symptoms, tell your doctor about any side effects.

If any of the side effects become serious, or if you notice any side effects not listed in this leaflet, tell your doctor or pharmacist.

How to store this medicine

Keep out of the sight and reach of children.

Do not use after the expiry date stated on the carton and blister after "EXP". The expiry date refers to the last day of that month.

This medicine does not require any special storage conditions.

Medicines should not be disposed of in wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer need. These measures will help protect the environment.