Efavirenz

Brand Name:Sustiva

Prescription needed: Yes

What is this drug used for?

Efavirenz is used in combination with other medications to treat HIV infection. It works to slow down the growth of the virus and to decrease the production of new virus particles in the body. As a result, this may help to delay and/or prevent the development of complications. This drug is not a cure for HIV and it will not prevent the virus from being spread to others.

Is there any reason not to take this drug?

You should not take this drug if you are allergic to efavirenz or if you are pregnant. Before taking this medication, tell your doctor specifically if you have or have ever had:
  • a problem with alcohol or drug abuse
  • hepatitis B or C
  • problems with your liver or kidney
  • problems with mental illness
  • feelings of depression or thoughts of suicide
  • seizures

What about possible side effects?

The most common side effects of this medication include:
  • rash
  • nausea, vomiting, diarrhea
  • dizziness
  • drowsiness
  • fatigue
  • trouble falling or staying asleep
  • difficulty concentrating

Other less common side effects include:

  • increase in cholesterol levels
  • infrequent cases of hepatitis (inflammation of the liver) have been reported.– greater chance if have hepatitis B or C
  • feeling depressed, suicidal, paranoid or having hallucinations (greater chances if have history of mental illness) – contact your doctor if this occurs
  • increase in waist size through redistribution of fat around the middle

This is not a complete list of side effects. If you are concerned about these or other unusual symptoms while taking this medication, ask your doctor and/or pharmacist for more information and advice.

What if I am taking other drugs?

Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications and herbal/natural products) as they may interact with and/or may change the safety or effectiveness of either drug. Tell your doctor specifically if you are taking any of these drugs as he/she may need to make changes or monitor you more closely:
  • amprenavir, atazanavir, ritonavir, indinavir, saquinavir (may see changes in the amount of these drugs in the blood)
  • clarithromycin (may increase levels of clarithromycin, increase chances of having a rash)
  • ergot derivatives (ergotamine, dihydroergotamine, methylergot; increased chance of side effects to these medications)
  • methadone (may decrease the amount of methadone in the blood)
  • midazolam (may see increase in the amount of midazolam in the blood)
  • rifabutin (may see a decrease in the amount of rifabutin in the blood)
  • rifampin (may see a decrease in the amount of efavirenz in the blood)
  • carbamazepine, phenytoin (may see a lower amount of these or efavirenz in the blood)
  • sertraline (may decrease the amount of sertraline in the blood)
  • St. John's wort (Hypericum perforatum) (may decrease the amount of efavirenz in the blood)
  • voriconazole, ketoconazole, itraconazole (may see lower amounts of these drugs in the blood)
  • warfarin (may see changes in the amount of warfarin in the blood)

This is not a complete list of drug interactions. Ask your doctor or pharmacist to review your list of medications.

Other information:

When to take: Although it is generally recommended that this medication be taken on an empty stomach, you should discuss this with your pharmacist or doctor first. They may give you different instructions depending on the other medications that you are taking.

Women: Women of childbearing age should use two different forms of birth control while taking this drug: a barrier method and an oral or other hormonal method of contraception.

Lab Tests: Your doctor will likely require regular blood tests to see how well the drug is working against the virus and to look for changes in cholesterol and triglyceride levels.

Children: Not prescribed to children under the age of 3. Lower dose is necessary in older children.

Seniors: Reduced dose may be necessary.

Pregnancy: Not recommended. Can cause harm to the baby, especially in the first trimester. Talk to your doctor.

Women who are nursing: Not recommended. Safety not established. Talk to your doctor.

People who drive or operate machinery: Should not do so until they know the impact this drug has on them personally.

Overdose: If you experience any unusual reactions or if you seriously exceed the recommended dosage, call your doctor or 911.

Stopping the drug: Always talk to your doctor before you stop taking this drug. When people stop this medication or similar medications for HIV, it is usually because of side effects. Before doing so, talk to your doctor or pharmacist about ways that the side effects could be decreased. They will likely have advice on ways that the medication can be taken to help with the side effects.

If you miss a dose: Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next dose, then return to your regular dosing schedule. It is important not to regularly miss doses of efavirenz since the virus may develop resistance to the medication and the medication may not work anymore. If you are unsure of what to do, talk to your doctor or pharmacist.

Storage conditions: Closed container; cool, dry location away from excess moisture (not in the bathroom); direct light, always out of reach of children.

Alcohol: Try to minimize consumption as alcohol may increase your chances of experiencing some side effects to efavirenz.

Dietary Precautions: See above.