Post Exposure Prophylaxis - The AIDS InfoNet

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New Mexico AIDS InfoNet

Fact Sheet Number 154

POST EXPOSURE PROPHYLAXIS

WHAT IS POST EXPOSURE PROPHYLAXIS?
WHO SHOULD USE PEP?
SHOULD PEP BE USED FOR NON-OCCUPATIONAL
EXPOSURE?
HOW IS PEP TAKEN?
WHAT ARE THE SIDE EFFECTS?
THE BOTTOM LINE
FOR MORE INFORMATION

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WHAT IS POST-EXPOSURE PROPHYLAXIS?

Prophylaxis means disease prevention. Post-exposure prophylaxis

(or PEP) means taking antiviral medications as soon as possible

after exposure to HIV, so that the exposure will not result in

HIV infection. These medications are only available with a prescription.

WHO SHOULD USE

PEP?

Workplace exposure: PEP has been standard procedure

since 1996 for healthcare workers exposed to HIV. Workers start

taking medications within a few hours of exposure. Usually the

exposure is from a “needle stick”, when a health care

worker accidentally gets jabbed with a needle containing HIV-infected

blood. PEP reduced the rate of HIV infection from workplace exposures

by 79%. However, some health care workers who take PEP still get

HIV infection.

Other exposure: In the last few years, community

activists and researchers began asking why PEP shouldn’t be used

after HIV exposures that are not work-related. People can be exposed

to HIV during unsafe sexual activity, when a condom breaks during

sex, or if they share needles for injecting drugs. Infants can

be exposed if they drink breast milk from an infected woman. In

a study of PEP in 400 cases of possible sexual exposure to HIV,

not one person became infected with HIV.

SHOULD PEP BE

USED FOR NON-OCCUPATIONAL EXPOSURE?

HIV exposure at work is usually a one-time accident. Other HIV

exposures may be due to unsafe behaviors that can occur many times.

Some people think that PEP might encourage this unsafe behavior

if people think that PEP is an easy way to avoid HIV infection.

There are other reasons why PEP might not be a good idea for non-occupational

exposure:

There is no research to show that PEP works for non-occupational
exposure. We don’t know how soon after exposure to HIV someone

has to start PEP.
PEP is not a “morning-after pill”. It is a program
of several drugs, several times each day, for at least 30 days.

PEP costs between $600 and $1,000.
For best results, you have to take every dose of every PEP
medication. Missing doses could mean that you develop HIV infection.

It could also allow the virus to develop resistance to the medications.

If that happens they would no longer work for you.
The medications have serious side effects. About 40% of health
care workers did not complete PEP because of the side effects.

Despite these concerns, a few cities are starting to offer

PEP for non-occupational exposure. These programs include counseling

to inform and encourage people to avoid exposure to HIV.

HOW IS PEP TAKEN?

PEP should be started as soon as possible after exposure to HIV.

The medications used in PEP depend on the exposure to HIV. The

following situations are considered serious exposure:

Exposure to a large amount of blood
Blood came in contact with cuts or open sores on the skin
Blood was visible on a needle that stuck someone
Exposure to blood from someone who has a high viral load
(a large amount of virus in the blood).

For serious exposures, the U.S. Public Health Service recommends

using a combination of three approved antiviral drugs for four

weeks. For less serious exposure, the guidelines recommend four

weeks of treatment with two drugs: AZT

and 3TC.

In January 2001, the Centers for Disease Control warned against

using nevirapine for PEP because of the risk of liver damage.

See Fact Sheet 431 for more

information on nevirapine.

WHAT ARE THE SIDE

EFFECTS?

The most common side effects from PEP medications are nausea and