PrEP and nPEP are both treatment regimens used for HIV prophylaxis. However, both treatment regimens are very different from each other in their indications and the time of use.
PrEP, or pre-exposure prophylactic treatment, is – as the name suggests – a pre-exposure regimen that is taken regularly to stay protected from possible HIV exposures. On the other hand, nPEP is a post-exposure regimen, meaning that it is only used in emergencies – for example, when a possible exposure to HIV has already taken place. Other differences between the two regimens include a choice of approved drugs, their duration of use, and the level of protection they provide. None of the regimens can be referred to as HIV treatment since they only prevent HIV, not treat the infection.
Both of these regimens are extremely effective in preventing HIV, granted that certain prerequisites are met timely. Your doctor may prescribe either one depending on whether the exposure to HIV has already occurred or not.
KEY DIFFERENCES BETWEEN PrEP AND nPEP
To understand the key differences between these two regimens, exploration of each of these treatment modalities is important.
PrEP, as mentioned above, is used to provide prophylaxis against HIV before a possible HIV exposure. This means that an individual takes the drugs included in this regimen before being exposed to the virus. PrEP is for people who are at a greater risk of acquiring HIV. These people exhibit certain risk behaviors, including having multiple sexual partners, having frequent unprotected sex, and having an HIV-positive partner, among others. PrEP is a choice that provides excellent protection against HIV when taken regularly.
The other prophylactic treatment modality for HIV is nPEP, which protects from HIV after a possible exposure to HIV has already taken place. As is evident, nPEP is taken in emergencies. The treatment has to be started within 36 hours of possible HIV exposure, and it is most effective when taken within the first 24 hours.
Other than the indications for both these treatment regimens, there are other differences as well. PrEP needs to be taken regularly before the drug levels in a patient's blood reach a high enough amount to confer adequate protection against HIV. Typically, a person has to take PrEP for 7 days before indulging in anal sexual intercourse and 20 days before having vaginal intercourse to enjoy viable protection. On the other hand, nPEP is taken within 24 hours of exposure, and it starts to provide immediate protection against the virus. However, nPEP is still taken for at least 28 days straight after a high-risk exposure to ensure maximum protection.
The levels of protection conferred by both these regimens are also different. PrEP, when taken regularly, can provide up to 99% protection against HIV. However, the level of protection decreases significantly when doses are missed. The other regimen, nPEP, provides up to 80% protection from the virus when taken within the first 24 hours of exposure and taken for 28 days straight.
HOW IS HIV TREATED?
Since HIV is not curable, the treatment persists for the rest of your life once you acquire the infection. The treatment for HIV is centered on lowering the "viral load" in your bloodstream.
The viral load of HIV is the detectable amount of HIV in your blood that is picked up by different HIV tests. The lower the viral load, the better the prognosis for the disease. Ideally, your viral load should remain undetectable while on medication for HIV. An undetectable viral load means the virus in your blood is negligible, HIV tests cannot pick it up.
Important to note here is that neither PrEP nor nPEP treat HIV. Both of these treatment regimens are prophylactic and not curative in nature. Typically, HIV is treated with antiretroviral therapy. Antiretroviral therapy, or ART, attacks the viral genome directly. Up to 4 to 6 months after starting treatment with ART, your viral load can become undetectable.
Once undetectable viral loads are achieved, your chances of transmitting the virus to anyone through sexual contact decrease significantly. Thus, an undetectable viral load not only lowers your symptoms and improves your immunity but also protects those close to you.
Note that regular visits to your physician or healthcare provider are essential to prevent future flare-ups even after achieving undetectable viral loads. Getting tested for other sexually transmitted diseases (STDs) is also important since seropositive individuals are at a greater risk of acquiring other STDs.
HOW ARE PrEP AND nPEP SIMILAR?
Despite their key differences, there are quite a lot of similarities between the two HIV prophylactic regimens. For starters, both PrEP and nPEP are only for people who are HIV-negative. Granted that they have different indications (one pre-exposure and the other post-exposure), but their primary aim is still to prevent HIV and not treat it. Therefore, only seronegative people qualify for both these regimens.
Both PrEP and nPEP require HIV testing before and after starting the treatment. This ensures that the person starting treatment is seronegative and remains seronegative throughout treatment. However, more frequent testing may be required with PrEP since this regimen is taken far longer than nPEP. Your doctor may also require some other tests in conjunction with HIV testing on your follow-up visits.
One key similarity between the two prophylaxis regimens is that none protect against STDs other than HIV. Therefore, it is important to use a condom still while having sex – especially if you have multiple sexual partners or live with an HIV-positive partner. It is also important to note that once an HIV infection has ensued, both PrEP and nPEP are rendered useless.
PrEP OR nPEP, WHICH ONE IS RIGHT FOR ME?
The choice between the two prophylactic regimens for HIV depends upon one major factor: a high-risk HIV exposure. If you suspect that you have had a high-risk HIV exposure in the last 24 hours, you must talk to your doctor about it and get further testing done. Depending upon the nature of exposure, your doctor may start you on nPEP and order further testing simultaneously.
If you haven't had a recent high-risk HIV exposure but are concerned about getting the infection, you should talk to your doctor about this concern. Your doctor will ask you several questions about your personal and sexual life to evaluate your risk of acquiring HIV. Your doctor may also order some lab tests to evaluate the situation a little better. If you belong to a high-risk group for acquiring HIV, your doctor may advise you to start using PrEP therapy.
You are a candidate for taking PrEP if you exhibit any one of these high-risk behaviors for acquiring HIV:
- Sharing injecting needles for drug use
- Having unprotected sexual intercourse
- Having unprotected sexual intercourse with multiple partners
- Sharing oral hygiene products
- Having anal intercourse
The behaviors listed above are extremely high-risk for acquiring HIV. However, this is not an exhaustive list. There are many more factors that put you at a greater risk for acquiring the virus than others. For example, if your partner is HIV-positive, your chances of acquiring the virus through sex increase by manifolds. Other factors such as having an STD other than HIV also puts you at a greater risk for acquiring HIV.
Frequent testing is essential if you believe that you exhibit any of the high-risk factors mentioned above. You should talk to your doctor as soon as possible if you have any concerns regarding your sexual health.