Meds and you

27 September 2013


Efavirenz is an antiretroviral. Antiretrovirals are drugs that suppress the activity or replication of retroviruses such as HIV.


(Also known as EFV, EFZ)

Efavirenz is the active ingredient of Stocrin Capsules (Nappi Code: 893536-008, 862371-007) and Stocrin Tablets (Nappi Code: 703318-001).

General information
Efavirenz is an antiretroviral. Antiretrovirals are drugs that suppress the activity or replication of retroviruses such as HIV. This specific antiviral is classified as a nucleoside reverse transcriptase inhibitor, meaning that it directly inhibits an enzyme which is essential for the virus to multiply.

In South Africa efavirenz is registered for the treatment of infection with the human immunodeficiency virus (HIV), often in combination with two other antiretroviral drugs.

If not treated, HIV will advance to weaken the body's immune system, gradually chipping away to create grounds for other infections, which the body will find more and more difficult to protect itself against. HIV develops into acquired immune deficiency syndrome (AIDS) when your immune system has been severely weakened.

For efavirenz to be effective it has to be taken regularly. By skipping even a few doses the risk for treatment failure increases substantially. Try to ensure that you take all your doses, and at the correct time.

It should be understood that efavirenz is not a cure for HIV or AIDS, but is one of a variety of drugs that only restricts the advance of the virus, keeping the immune system up-and-running. It is used in combination with other antiretroviral drugs and should not be prescribed on its own.

Efavirenz does not reduce transmission of HIV. You can still infect another person with the virus and the use of appropriate precautions to prevent spread to other persons is highly recommended.

How does efavirenz work?
When HIV infects a human T cell, a type of white blood cell that plays a key role in the functioning of the immune system, viral genetic information in the form of RNA needs to be converted to DNA for the virus to be able to multiply. It makes use of an enzyme called reverse transcriptase to achieve this conversion. This drug, a reverse transcriptase inhibitor, binds directly to this enzyme and prevents the conversion of RNA to DNA thereby preventing the spread of HIV.

Fast facts

Drug schedule: schedule 4
Available as: efavirenz is available as tablets and capsules.
What does it do? Efavirenz is an anti-viral drug.
Overdose risk: medium
Dependence risk: low
Is efavirenz available as a generic? no
Is efavirenz available on prescription only? yes

User information

Dietary advice: efavirenz should best be taken with a high-fat meal.
Stopping this medicine: do not stop taking this drug without consulting your doctor.
Prolonged use: side-effects may develop with long-term use and frequent blood tests may be required with prolonged therapy to determine liver function.

Special precautions
Consult your doctor before using this drug if:

  • you have known liver or kidney problems

  • you have a history of psychiatric illness

  • you are taking other medication

Pregnancy: avoid. Potential risk to the foetus has been reported. Consult your doctor before use, or if you are planning to fall pregnant.
Breastfeeding: avoid. Not only can HIV infection be passed to your baby through breast milk, but efavirenz is also present and transmitted in breast milk.
Porphyria: avoid. It is unknown how this medication may affect your condition. Consult your doctor before use.
The elderly: caution is advised in the elderly as side effects may be more severe.
Infants and children: this medication is not intended for use in children under the age of 3 years.
Driving and hazardous work: caution is advised as use of this medication may lead to dizziness. Avoid such activities until you know how this medication affects you.
Alcohol: avoid concomitant use of alcohol with this medication.

Possible side effects

Side Effect
Consult your doctor

Only if severe
In all cases




abdominal pain


skin rash

abnormal thoughts












impaired concentration




Drug interactions

nelfinavir increased levels of nelvinavir in the body
oral contraceptives risk of reduced contraceptive effect
St. Johns Wort, Rifampicin reduced effect of efavirenz
amprenavir, indinavir, lopinavir, nelfinavir, ritonavir, saquinavir reduced effect of these agents

Many other drugs may interact with efavirenz. It is important to consult your doctor or pharmacist before combining any drug with efavirenz.

Disease interactions
Contact your doctor if you have a liver or kidney disease or if you have been diagnosed with a psychiatric illness.

Overdose action
A small overdose is no cause for concern. In case of intentional large overdose seek emergency medical attention.

Recommended dosage
Adults: oral, 600 mg/day

This material is not intended to substitute medical advice, but is for informational purposes only. Please consult a physician for specific treatment and recommendations.

Read Health24’s Comments Policy

Comment on this story
Comments have been closed for this article.