Skip to main content

Nelfinavir (Oral)

Generic name: nelfinavir [ nel-FIN-a-vir ]
Brand name: Viracept
Drug class: Protease inhibitors

Medically reviewed by Drugs.com. Last updated on May 12, 2023.

Uses for nelfinavir

Nelfinavir is usually used in combination with other medicines in the treatment of the infection caused by the human immunodeficiency virus (HIV). HIV is the virus that causes acquired immune deficiency syndrome (AIDS).

Nelfinavir will not cure or prevent HIV infection or AIDS. It helps keep HIV from reproducing and appears to slow down the destruction of the immune system. This may help delay the development of problems related to AIDS or HIV disease. Nelfinavir will not keep you from spreading HIV to other people. People who receive this medicine may continue to have other problems usually related to AIDS or HIV disease.

This medicine is available only with your doctor's prescription.

Before using nelfinavir

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of nelfinavir in children 2 years of age or older. However, safety and efficacy have not been established in children younger than 2 years of age.

Geriatric

Appropriate studies on the relationship of age to the effects of nelfinavir have not been performed in the geriatric population. However, no geriatric-specific problems have been documented to date.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

Proper use of nelfinavir

Take this medicine exactly as directed by your doctor. Do not take it more often, and do not take it for a longer time than your doctor ordered. Also, do not stop taking this medicine without first checking with your doctor. Keep taking nelfinavir for the full time of treatment, even if you begin to feel better.

It is important to take this medicine together with other medicines for HIV. Be sure to take all of the medicines your doctor ordered, and to take them at the right times.

This medicine comes with a patient information leaflet. Read and follow these instructions carefully before starting treatment and each time you refill your prescription. Ask your doctor if you have any questions.

Nelfinavir works best if it is taken with food.

If you are also using didanosine (Videx®), take it 1 hour before or at least 2 hours after taking nelfinavir.

If you cannot swallow the tablet whole, you may dissolve it in a small amount of water. Be sure to drink or swallow the entire mixture right away. Then refill the glass with water and drink it so none of the medicine is left on the sides of the glass.

Measure the powder carefully using the measuring scoop provided with the medicine. 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 apple sauce. After mixing your medicine with a liquid, use the mixture right away. Be sure to drink or swallow all of the mixture. If not used right away, you may store this mixture in the refrigerator for up to 6 hours.

This medicine works best when there is a constant amount in the blood. To help keep the amount constant, do not miss any doses. Also, it is best to take the doses at evenly spaced times during the day. For example, if you are to take three doses each day, the doses should be spaced about 8 hours apart. If you need help in planning the best times to take your medicine, check with your doctor.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep the bottle tightly closed. Keep the medicine in the original bottle that you were given at the pharmacy.

Precautions while using nelfinavir

If you will be taking this medicine for a long time, it is very important that your doctor check the progress of you or your child at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Do not use this medicine if you are also using alfuzosin (Uroxatral®), amiodarone Cordarone®), lovastatin (Advicor®, Altocor®, Mevacor®), lurasidone (Latuda®), oral midazolam (Versed®), pimozide (Orap®), quinidine (Quinaglute®), rifampin (Rifadin®), sildenafil (Revatio®), simvastatin (Simcor®, Vytorin®, Zocor®), triazolam (Halcion®), or ergot medicines (eg, dihydroergotamine, ergotamine, methylergonovine, DHE 45®, Ergomar®),

Using this medicine while you are pregnant can harm your unborn baby. Birth control pills may not work as well to prevent pregnancy when used with this medicine. Use another form of birth control (eg, condoms, spermicide) along with your pills. If you think you have become pregnant while using this medicine, tell your doctor right away.

This medicine may increase blood sugar levels. Check with your doctor right away if you or your child notice a change in the results of your blood or urine sugar tests, or if you have confusion, nausea or vomiting, increased hunger, thirst or urination, or unusual tiredness or weakness.

This medicine may cause you to have excess body fat. Tell your doctor if you or your child notice changes in your body shape, including an increased amount of fat in the upper back and neck, or around the chest and stomach area. You might also lose fat from the legs, arms, and face.

Your immune system may get stronger when you start taking HIV medicines. Tell your doctor right away if you notice any changes in your health. Sometimes the immune system will start to fight infections that were hidden in your body, such as pneumonia, herpes, or tuberculosis. Autoimmune disorders (eg, Graves' disease, polymyositis, and Guillain-Barré syndrome) may also occur.

This medicine will not keep you from giving HIV to your partner during sex. Make sure you understand this and practice safe sex, even if your partner also has HIV, by using a latex condom or other barrier method. This medicine will not keep you from giving HIV to other people if they are exposed to your blood. Do not re-use or share needles with anyone.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription and nonprescription (over-the-counter [OTC]) medicines, and herbal (eg, St. John's wort) or vitamin supplements.

Side Effects of nelfinavir

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

Incidence not known

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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

Commonly used brand name(s)

In the U.S.

Available Dosage Forms:

Therapeutic Class: Antiretroviral Agent

Pharmacologic Class: Protease Inhibitor

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.