Health Library

Nelfinavir (By mouth)

Nelfinavir (nel-FIN-a-vir)

Treats HIV infection. This medicine does not cure HIV or AIDS, but combinations of drugs may slow the progress of the disease.

Brand Name(s):

Viracept

When This Medicine Should Not Be Used:

How to Use This Medicine:

Powder, Tablet

• Your doctor will tell you how much medicine to use. Do not use more than directed.
• Nelfinavir is used together with other medicines to treat HIV infection. Take all of the medicines your doctor has prescribed at the right time of day and in the correct order. Do not stop using your medicine unless your doctor tells you to.
• It is best to take this medicine with food or milk.
• Tablet: If you cannot swallow it whole, you may dissolve the tablet in a small amount of water. Drink all of the mixture after the tablet dissolves. Then refill your glass with water and drink all of the water right way, so that no medicine is left in the glass.
• Oral powder: Measure the medicine carefully with the measuring scoop provided. Mix the powder with a small amount of water, milk, soy milk, baby formula, or a dietary supplement drink. Do not use apple juice, orange juice, or applesauce. After you mix the medicine with a liquid, drink all of the mixture right away. If you cannot use the mixture right away, you may store it in the refrigerator for up to 6 hours.
• Do not stop using this medicine without checking first with your doctor. If you stop the medicine even briefly, the virus may become harder to treat. Contact your doctor or pharmacist when your supply is running low so you do not run out.
• Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
• Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep the bottle tightly closed. Keep the medicine in the original bottle that you were given at the pharmacy.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Do not use this medicine if you are also using alfuzosin, amiodarone, cisapride, dihydroergotamine, ergotamine, lovastatin, lurasidone, methylergonovine, oral midazolam, pimozide, quinidine, rifampin, sildenafil, simvastatin, St John's wort, or triazolam.
• Many other drugs can interact with nelfinavir. Make sure your doctor knows about all other medicines you are using.
• If you also use didanosine, take it 1 hour before or at least 2 hours after you take nelfinavir.

Warnings While Using This Medicine:

• It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant. Birth control pills may not work as well to prevent pregnancy when used with this medicine. Use another form of birth control (including condoms or spermicide) along with your pills.
• Do not breastfeed. You can spread HIV or AIDS to your baby through your breast milk.
• Tell your doctor if you have kidney disease, liver disease, diabetes, hemophilia, or phenylketonuria.
• This medicine may cause the following problems:
  • High blood sugar
  • Increased risk of bleeding
• Always practice safe sex, even if your partner also has HIV. If you stop taking this medicine or do not take it as prescribed, you may spread HIV to others. Do not reuse or share needles, or other items, that may have blood or body fluids on them.
• Your immune system may get stronger when you start taking an HIV medicine. Infections that were hidden in your body, including pneumonia or tuberculosis, might start to have symptoms. Tell your doctor right away if you notice any changes in your health.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Fever, chills, cough, sore throat, body aches
• Increased hunger or thirst, change in how much or how often you urinate, unusual weight loss
• Unusual bleeding, bruising, or weakness

If you notice these less serious side effects, talk with your doctor:

• Diarrhea, gas, nausea, stomach pain, loss of appetite
• Weight gain around your neck, upper back, breast, or waist

If you notice other side effects that you think are caused by this medicine, tell your doctor

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

Last Updated: 9/6/2024