Brand Name(s):
  • Viracept®
WHY is this medicine prescribed?

Nelfinavir is used along with other medications to treat human immunodeficiency virus (HIV) infection. Nelfinavir is in a class of medications called protease inhibitors. It works by decreasing the amount of HIV in the blood. Although nelfinavir does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Taking these medications along with practicing safer sex and making other life-style changes may decrease the risk of transmitting the HIV virus to other people.

HOW should this medicine be used?

Nelfinavir comes as a tablet and a powder to take by mouth. It is usually taken two to three times a day with food. Take nelfinavir at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take nelfinavir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you are unable to swallow the tablet, you may put it in a glass and dissolve it in a small amount of water. Mix the liquid well, and drink it immediately. Rinse the glass with more water and swallow the entire mixture to make sure you have taken all of the medication.

Nelfinavir oral powder may be added to water, milk, formula, soy milk, or dietary supplements. Mix well, and drink all of the liquid right away in order to take the full dose. Your prescription label tells you how many scoops of nelfinavir powder to add to the liquid. If the mixture is not taken immediately it must be stored in the refrigerator and taken within 6 hours. Do not mix nelfinavir oral powder with acidic food or juice (orange juice, apple juice, or apple sauce). Do not mix nelfinavir with water in the original container.

Nelfinavir controls HIV infection but does not cure it. Continue to take nelfinavir even if you feel well. Do not stop taking nelfinavir without talking to your doctor. If you stop taking nelfinavir or skip doses, your infection may get worse or become resistant to medications.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Are there OTHER USES for this medicine?

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

What SPECIAL PRECAUTIONS should I follow?

Before taking nelfinavir,

  • tell your doctor and pharmacist if you are allergic to nelfinavir, any other medications, or any of the ingredients in nelfinavir tablets or powder. Ask your pharmacist for a list of the ingredients.
  • tell your doctor if you are taking alfuzosin (Uroxatral); amiodarone (Cordarone, Pacerone); cisapride (Propulsid) (not available in the U.S.); ergot-type medications such as bromocriptine (Parlodel), cabergoline (Dostinex), dihydroergotamine (D.H.E. 45, Migranal), ergoloid mesylates (Gerimal, Hydergine), ergotamine (Cafergot, Ergomar, in Migergot, others), and methylergonovine (Methergine); lovastatin (in Advicor, Altoprev, Mevacor); midazolam (Versed) by mouth; pimozide (Orap); quinidine (Quinaglute, Quinalan, Quinidex, others); rifampin (Rimactane, Rifadin, in Rifater, in Rifamate); sildenafil (only Revatio brand used for lung disease); simvastatin (in Simcor, in Vytorin, Zocor); and triazolam (Halcion). Your doctor will probably tell you not to take nelfinavir if you are taking one or more of these medications.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: azithromycin (Azasite, Zithromax, Zmax); bosentan (Tracleer); certain calcium-channel blocking medications such as amlodipine (Norvasc, in Caduet, Lotrel), felodipine (Plendil, in Lexxel), isradipine (DynaCirc), nicardipine (Cardene), nifedipine (Adalat, Nifedical, Procardia), nimodipine (Nimotop), and nisoldipine (Sular); carbamazepine (Carbatrol, Epitol, Equetro, Tegretol, others); certain cholesterol-lowering medications (statins) such as atorvastatin (Lipitor) and rosuvastatin (Crestor); colchicine (Colcrys); delavirdine (Rescriptor); fluticasone (in Advair, Flonase, Flovent); indinavir (Crixivan); medications that suppress the immune system such as cyclosporine (Gengraf, Neoral, Sandimmune), sirolimus (Rapamune), and tacrolimus (Prograf); methadone (Dolophine, Methadose); nevirapine (Viramune); certain phosphodiesterase inhibitors (PDE-5 inhibitors) used for erectile dysfunction such as sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra); phenobarbital; phenytoin (Dilantin, Phenytek, others); proton-pump inhibitors such as esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec), pantoprazole (Protonix), and rabeprazole (AcipHex); rifabutin (Mycobutin); rifampin (Rimactane, in Rifamate, in Rifater, Rifadin); ritonavir (Norvir in Kaletra); salmeterol (in Advair, Serevent); saquinavir (Fortovase, Invirase); tadalafil (Adcirca); trazodone; and warfarin (Coumadin, Jantoven). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with nelfinavir, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • tell your doctor and pharmacist what herbal products you are taking, especially St. John's wort. You should not take St. John's wort during your treatment with nelfinavir.
  • if you are taking didanosine (Videx), take it 1 hour before or more than 2 hours after nelfinavir.
  • tell your doctor if you are taking birth control pills. Nelfinavir can decrease the effectiveness of oral contraceptives. You should use another method of birth control while taking this medication. Talk to your doctor about birth control while taking nelfinavir.
  • tell your doctor if you have or have ever had diabetes, hemophilia (a group of inherited bleeding disorders in which the ability of blood to clot is not normal),or liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking nelfinavir, call your doctor. You should not breast-feed if you have HIV infection and are taking nelfinavir.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking nelfinavir.
  • you should be aware that your body fat may increase or move to different areas of your body, such as your upper back, neck ('buffalo hump'), breasts, and around your stomach. You may notice a loss of body fat from your face, legs, and arms.
  • you should know that you may experience hyperglycemia (increases in your blood sugar) while you are taking this medication, even if you do not already have diabetes. Tell your doctor immediately if you have any of the following symptoms while you are taking nelfinavir: extreme thirst, frequent urination, extreme hunger, blurred vision, or weakness. It is very important to call your doctor as soon as you have any of these symptoms, because high blood sugar that is not treated can cause a serious condition called ketoacidosis. Ketoacidosis may become life-threatening if it is not treated at an early stage. Symptoms of ketoacidosis include: dry mouth, nausea and vomiting, shortness of breath, breath that smells fruity, and decreased consciousness.
  • if you have phenylketonuria (PKU, an inherited condition in which a special diet must be followed to prevent mental retardation), you should know that nelfinavir oral powder is sweetened with aspartame that forms phenylalanine.
  • you should know that while you are taking medications to treat HIV infection, your immune system may get stronger and begin to fight other infections that were already in your body. This may cause you to develop symptoms of those infections. If you have new or worsening symptoms at anytime during your treatment with nelfinavir, be sure to tell your doctor.
What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Nelfinavir may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • diarrhea
  • nausea
  • gas
  • stomach pain
  • loss of appetite
  • rash

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

  • hives
  • itching
  • difficulty breathing or swallowing

Nelfinavir contains a chemical found to cause cancer in laboratory animals. The Food and Drug Administration (FDA) has asked the manufacturer to make changes in the way nelfinavir is made to decrease the amount of this chemical in nelfinavir products. The risk to humans is unknown, but may be higher in children and pregnant women. Talk to your doctor about the risks of taking nelfinavir.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at Web Site] or by phone [1-800-332-1088].

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). After nelfinavir powder has been added to liquid, the mixture may be kept at room temperature for up to 6 hours. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

What should I do in case of OVERDOSE?

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to nelfinavir.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Keep a supply of nelfinavir on hand. Do not wait until you run out of medication to refill your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: September 15, 2012.