Frequently asked questions about PEP (Post Exposure Prophylaxis)

What is PEP?  

PEP is the after exposure medication i.e antiretroviral medicines (ART) taken within 72 hours upon suspected HIV exposure. PEP is a combination of pills that need to be for 1 month. 

How effective is PEP?

Research has shown that PEP can prevent approximately 90% who have been exposed from being infected by HIV if taken properly as directed. 

What are the original drugs for PEP? Is there any difference with the generic drugs?

Truvada is the original HIV drug and considered as a “backbone” medication. That means it’s one of the drugs that an HIV treatment plan is based on. Truvada is used in combination with other HIV drugs such as Isentress or Tivicay as PEP. Furthermore, Truvada is the only drug that is approved by US Food and Drug Administration (FDA) for PrEP use since 2012.

Truvada has its generic counterpart, called Tenof-Em or Tenvir-EM. So, is there any difference?

Generic medicine, in general, should work in the same way and provides the same clinical benefit as its original version. However, bear in mind that the only studies on the effectiveness to prevent HIV, and their side effects, was done only on the original drugs (Truvada) and not on the generic ones.

Can you take PEP each time you have unprotected sex?

No. PEP should only be used in emergency situations. Thus, it is not the right choice for people who are frequently exposed to HIV and it is not intended to replace regular use of other HIV prevention methods.

So if you keep having unsafe sex, your doctor will usually offer help with having safer sex so you won’t be given PEP lots of times. Besides, the side effects such as stomach aches, nausea, diarrhoea, body pain and lethargy often put people off wanting to take PEP more than once.

For example, if you often have sex with a partner who is HIV-positive, it’s recommended to take other proven HIV prevention methods, such as pre-exposure prophylaxis (PrEP) and using condoms every time you are having sex.

What are the differences between PreP and PEP?

As mentioned previously, PEP is used after a suspected high risk exposure to HIV virus. PEP is a month-long course of drugs and must be started within 72 hours after possible exposure.

PrEP (pre-exposure prophylaxis), on the other hand, is a prevention method used by people who are engaged in high risk behaviour on a regular basis. PrEP is a once-daily dosing of the medication that reaches its protection effect after at least 7 days of daily use.

Studies have shown that PrEP reduces the risk of getting HIV from sex by about 99%. PrEP can be taken for as long as you are at risk of contracting HIV. Research also showed that PrEP can be taken up to 5 years without significant health effects.

Read more about PrEP here.

If you are on PEP, does that make you immune to HIV while you are on it or once you have stopped taking it?

No. PEP doesn’t make you immune to HIV. In addition, further high risk exposure such while you are on PEP may cause a new infection.

Remember, PEP does not protect you lifelong like a vaccine. Furthermore, even after you have finished taking PEP and stayed HIV negative. The chances of you becoming infected after that will be the same like any other HIV negative person if practice unsafe sex again.

Does it matter so much if people don’t use condoms since now we have PEP?

Here’s why PEP doesn’t change the need for condoms:

  • Using a condom reduces the chance of HIV being passed on significantly.
  • Condoms don’t have the side effects of PEP
  • PEP has to be taken for 4 weeks – but condom is only for as long as the sex lasts 
  • PEP doesn’t protect you from other STDs such as syphilis, gonorrhea or chlamydia.

Do you need to do an HIV test before starting PEP?

Yes, you should consider doing a blood test for HIV since PEP is for prevention of HIV but if you are already HIV positive you should be getting treatment. While you are at it, you should screen for other STDs as well such as Hepatitis B, gonorrhoea, chlamydia, herpes and syphilis.

Can you stop taking PEP if you choose to (as in not complete 28 days)?

No. If you stop taking PEP halfway or you do not complete the PEP course. This might  lead to treatment failure and in turn resulting in HIV seroconversion (HIV positive). It’s important that you take every pill as directed and don’t skip dosage. Otherwise, PEP will not be as effective. Multiple studies have shown that the effectiveness of PEP in preventing HIV serocoverison is very dependent on the person taking the medications as prescribed.

Is PEP a cure for HIV?

There is no cure for HIV. However, PEP can help prevent HIV infection if it was taken very early on after HIV enters the body. HIV virus will take around 72 hours to establish itself in the body following exposure. 

If PEP is given within this period, it will prevent the  HIV that’s already in your body from reproducing and replicating in your body.

Who should consider taking PEP? 

PEP might be right for people who may have been exposed to HIV in the last 72 hours:

  • If you had sex with someone who may have HIV and didn’t use a condom, or the condom broke
  • If you had shared needles with someone who may have HIV
  • If you are sexually assaulted

Is PEP fail proof if taken within 72 hours?

Although in certain cases it does fail. However, it reduces the chances of you becoming infected with HIV significantly if taken properly. In this certain unfortunate circumstances, the treatment might failed due to :

  • Poor compliance with the medication – the person fails to take the drug as prescribed
  • In rare occasion, the anti-HIV drugs don’t work against some strains of HIV (due to HIV drug resistance) 

What to do AFTER you have completed your 28 days course of PEP?

Once you have completed your PEP, your doctor would recommend a HIV test. Then, you should be tested again for HIV after 3 months of your last exposure for the final confirmation.

Does PEP have side effects?

PEP is generally well-tolerated by patients. Though, side effects can still happen such as stomach aches, nausea, diarrhoea and lethargy. However, these side effects aren’t dangerous and they usually get better with time, once your body gets used to PEP. 

However, in some people, although uncommon, it could still also get worse. This includes rash, renal impairment and liver toxicity but these side-effects occur very rarely.

There have been occasional reports with the use of certain PEP combinations causing muscle-related adverse events such as myalgia (muscle pain), and rhabdomyolysis (muscle damage that can lead to renal complications). Thus, caution should, therefore, be taken in individuals with a history of pre-existing kidney problem or who are using other medications associated with these conditions (such as statin-induced rhabdomyolysis).

Next read: A Guide To Pills That Prevent HIV / AIDS (HIV PEP & HIV PrEP)

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