Nelfinavir

Adult Medication
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This information from Lexicomp® explains what you need to know about this medication, including what it’s used for, how to take it, its side effects, and when to call your healthcare provider.

Brand Names: US

Viracept

Brand Names: Canada

Viracept [DSC]

What is this drug used for?

  • It is used to treat HIV infection.

What do I need to tell my doctor BEFORE I take this drug?

  • If you are allergic to this drug; any part of this drug; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
  • If you have liver disease.
  • If you take any drugs (prescription or OTC, natural products, vitamins) that must not be taken with this drug, like certain drugs that are used for high cholesterol, migraines, mood problems, and others. There are many drugs that must not be taken with this drug.
  • If you are pregnant, may become pregnant, or are breast-feeding. Before taking this drug, you will need to talk about the benefits and risks to you and the baby. You will also need to talk about the best way to prevent passing HIV to the baby.

This is not a list of all drugs or health problems that interact with this drug.

This drug interacts with many other drugs. The chance of severe, life-threatening, or deadly side effects may be raised. Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this drug with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take this drug?

For all patients taking this drug:

  • Tell all of your health care providers that you take this drug. This includes your doctors, nurses, pharmacists, and dentists.
  • High blood sugar has happened with this drug. This includes diabetes that is new or worse.
  • Check your blood sugar as you have been told by your doctor.
  • Some people with hemophilia have had times of more bleeding when taking drugs like this one. If you have hemophilia, talk with your doctor.
  • Have your blood work and other lab tests checked as you have been told by your doctor.
  • This drug is not a cure for HIV. Keep taking this drug as you have been told by your doctor or other health care provider, even if you feel well. Be sure to stay under the care of your doctor and have regular appointments.
  • This drug helps to lower how much HIV is in the blood. Lowering the amount of HIV in the blood until it is not detected on blood tests can help lower the risk of spreading HIV to others. There are also other ways to help prevent the spread of HIV to others. This includes using condoms during sex and not sharing needles and other injection equipment. Talk with your doctor or other health care provider about the best way to prevent spreading HIV to others.
  • If you have phenylketonuria (PKU), talk with your doctor. Some products have phenylalanine.
  • Birth control pills and other hormone-based birth control may not work as well to prevent pregnancy. Use some other kind of birth control also like a condom when taking this drug.

Children:

  • If the patient is a child, use this drug with care. The risk of some side effects may be higher in children.
  • If your child’s weight changes, talk with the doctor. The dose of this drug may need to be changed.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Signs of high blood sugar like confusion, feeling sleepy, unusual thirst or hunger, passing urine more often, flushing, fast breathing, or breath that smells like fruit.
  • Any unexplained bruising or bleeding.
  • Change in body fat.
  • Changes in your immune system can happen when you start taking drugs to treat HIV. If you have an infection that you did not know you had, it may show up when you take this drug. Tell your doctor right away if you have any new signs after you start this drug, even after taking it for several months. This includes signs of infection like fever, sore throat, weakness, cough, or shortness of breath.

What are some other side effects of this drug?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Diarrhea, stomach pain, upset stomach, or decreased appetite.
  • Gas.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to your national health agency.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

How is this drug best taken?

Use this drug as ordered by your doctor. Read all information given to you. Follow all instructions closely.

All products:

  • Take with meals.
  • It is important that you do not miss or skip a dose of this drug during treatment.
  • Do not take didanosine within 1 hour before or 2 hours after taking this drug.

Tablets:

  • If you cannot swallow this drug whole, you may dissolve it in water. Once your dose is dissolved, mix well and drink right away. Rinse the glass with more water and drink.

Powder:

  • Mix the powder with a little bit of water, milk, formula, soy formula, or soy milk and drink.
  • Avoid mixing with acidic foods such as apple juice, applesauce, or orange juice.
  • Rinse cup with more water and drink.
  • If mixing with water, do not mix with water in its original container.

What do I do if I miss a dose?

  • Take a missed dose as soon as you think about it.
  • If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
  • Do not take 2 doses at the same time or extra doses.
  • If you are not sure what to do if you miss a dose, call your doctor.

How do I store and/or throw out this drug?

All products:

  • Store at room temperature in a dry place. Do not store in a bathroom.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

Powder:

  • Use right away after mixing or you may store in a refrigerator for up to 6 hours.

General drug facts

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else’s drugs.
  • Some drugs may have another patient information leaflet. If you have any questions about this drug, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this drug, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Consumer Information Use and Disclaimer

This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider’s examination and assessment of a patient’s specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms.

Last Reviewed Date

2024-06-20

Copyright

© 2024 UpToDate, Inc. and its affiliates and/or licensors. All rights reserved.

Last Updated

Monday, December 12, 2022