Nelfinavir can cause serious, life-threatening side effects. These include liver problems in people with moderate or severe liver impairment and life-threatening drug interactions. Nelfinavir oral powder contains aspartame and should not be used by people with phenylketonuria.
While taking nelfinavir, it is important to keep all of your appointments with your health care provider.
What is nelfinavir?
Nelfinavir is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in adults and children 2 years of age and older. Nelfinavir is always used in combination with other anti-HIV medicines.
Nelfinavir is a type of anti-HIV medicine called a protease inhibitor (PI). Nelfinavir works by blocking protease, an HIV enzyme. This prevents HIV from replicating and lowers the amount of HIV in the blood.
Nelfinavir does not cure HIV/AIDS. It is not known if nelfinavir reduces the risk of passing HIV to other people.
What should I tell my health care provider before taking nelfinavir?
Before taking nelfinavir, tell your health care provider:
- If you are allergic to nelfinavir or any other medicines.
- If you have liver disease. People with moderate or severe liver disease should not use nelfinavir.
- If you have kidney disease.
- If you have phenylketonuria (PKU). Nelfinavir oral powder contains aspartame and should not be used by people with phenylketonuria.
- If you have diabetes or high blood sugar.
- If you have hemophilia.
- If you have any other medical condition.
- If you are pregnant or plan to become pregnant. Whether nelfinavir can harm an unborn baby is unknown.
- If you are breastfeeding or plan to breastfeed. Do not breastfeed if you are infected with HIV or are taking nelfinavir.
- About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Nelfinavir may affect the way other medicines or products work, and other medicines or products may affect how nelfinavir works. Taking nelfinavir with certain medicines or products may cause serious and/or life-threatening side effects.
How should I take nelfinavir?
Nelfinavir comes in the following forms and strengths:
- 250-mg tablets (brand name: Viracept).
- 625-mg tablets (brand name: Viracept).
- 50-mg/g oral powder (brand name: Viracept).
Take nelfinavir according to your health care provider’s instructions.
Nelfinavir tablets should always be taken with a meal. If you or your child has trouble with swallowing the tablets, you can dissolve the tablets in a small amount of water. Once the tablets are dissolved, the liquid will be cloudy. Mix the cloudy liquid well and drink immediately. The glass should be rinsed with water, and then the rinse should be swallowed.
Nelfinavir oral powder is another option for people who have trouble with swallowing nelfinavir tablets. The oral powder may be mixed with a small amount of water, milk, formula, soy formula, soy milk, or liquid dietary supplements. Do not mix oral powder in the container that it comes in. Do not mix the powder with any acidic food or juice. Once mixed, the entire amount must be taken. If the mixture is not consumed immediately, it must be stored in the refrigerator, but not for longer than 6 hours.
If you are also taking the anti-HIV medicine didanosine (brand name: Videx; Videx EC), take nelfinavir with food 1 hour after or more than 2 hours before you take didanosine.
Always take nelfinavir in combination with other anti-HIV medicines.
If you take too much nelfinavir, contact your local poison control center (1-800-222-1222) or go to the nearest hospital emergency room right away.
For more information on how to take nelfinavir, see the FDA drug label from DailyMed. (DailyMed is a federal website that includes the most recent drug labels submitted to FDA.) Toward the end of the label is patient information for people taking nelfinavir.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. But if it is almost time for your next dose, skip the missed dose and just take your next dose at the regular time. Do not take two doses at the same time to make up for a missed dose.
What side effects can nelfinavir cause?
Nelfinavir can cause serious, life-threatening side effects. These include liver problems in people with moderate or severe liver impairment and life-threatening drug interactions. Nelfinavir oral powder contains aspartame and should not be used by people with phenylketonuria. (See the WARNING above.)
Other possible side effects of nelfinavir include:
- Diabetes and high blood sugar (hyperglycemia).
- Increased bleeding in people with hemophilia.
- Changes in body fat (lipodystrophy).
- Changes in your immune system (immune reconstitution inflammatory syndrome).
Tell your health care provider if you have any side effect that bothers you or that does not go away.
These are not all the possible side effects of nelfinavir. Ask your health care provider or pharmacist for more information on possible side effects of nelfinavir.
How should nelfinavir be stored?
- Store nelfinavir tablets and oral powder at room temperature, 59°F to 86°F (15°C to 30°C).
- Store nelfinavir in its original container and keep the container tightly closed.
- Safely throw away nelfinavir that is no longer needed or expired (out of date).
- Keep nelfinavir and all medicines out of reach of children.
Where can I find more information about nelfinavir?
More information about nelfinavir is available:
Last Reviewed: September 13, 2012
Last Updated: August 23, 2013