HIV PEP Singapore | Shim Clinic

HIV post-exposure prophylaxis (PEP) is an emergency course of prescription antiretroviral medicine taken after a possible exposure to HIV. It must be started quickly: ideally as soon as possible and no later than 72 hours after the event. Every hour matters because PEP is intended to stop HIV from establishing infection. If you are worried about a recent exposure in Singapore, contact Shim Clinic promptly for a private medical assessment rather than waiting for symptoms or for the window to pass.

PEP is usually taken every day for 28 days. It can substantially reduce the chance of acquiring HIV when it is appropriate, started promptly, and taken exactly as prescribed, but it is not 100% effective. It is not a cure for an infection that was already established before treatment began, and it is not designed as routine prevention for frequent exposure.

When should you seek an urgent PEP assessment?

You should seek advice immediately if a possible exposure occurred within the last 72 hours. Situations that can warrant assessment include condomless vaginal or anal sex, a condom breaking or slipping, sharing needles or other injecting equipment, a needlestick injury, sexual assault, or blood or potentially infectious genital fluid contacting a mucous membrane, open wound, sore, or damaged skin.

Not every incident carries the same likelihood of HIV transmission, and not every concern requires PEP. Saliva, urine, tears, and sweat are generally not regarded as infectious fluids for HIV. The source person’s HIV status and viral suppression, the body fluid involved, the exposure site, whether skin was intact, and the time since exposure all affect the decision. A clinician needs to consider these details with you rather than make a decision from one fact alone.

Do not delay attendance while trying to obtain information about the other person. You can begin with what you know. If your exposure was more than 72 hours ago, PEP is generally outside its effective initiation window, but you should still arrange medical advice about HIV testing and other appropriate care.

What happens at Shim Clinic?

We begin with a focused, confidential consultation. We will ask when the event occurred, what type of contact took place, whether a condom or needle was involved, what is known about the source, and whether you have had other recent exposures. We will also review your health, allergies, current medicines and supplements, and relevant pregnancy or breastfeeding considerations.

PEP is intended for someone who does not have HIV or does not know their current HIV status. A baseline HIV test is therefore commonly part of assessment. Depending on your circumstances and the proposed medicines, baseline blood tests may include kidney and liver function. Testing for other sexually transmitted infections may also be discussed because PEP only addresses HIV: it does not prevent other infections and does not prevent pregnancy.

The purpose of baseline testing is not to create a reason for unnecessary delay. When PEP is indicated, the priority is rapid initiation within the 72-hour window. Your doctor will explain the recommended regimen, how to take it, what to do if a dose is missed, possible interactions, and the follow-up plan.

How HIV PEP works

After HIV enters the body, it needs to infect cells, make copies of itself, and spread before infection becomes established. The antiretroviral medicines used for PEP interfere with that process. Starting sooner gives the medicines a better opportunity to interrupt early replication. Once infection is established, a short PEP course cannot remove it, which is why timely assessment is essential.

The prescribed course is normally 28 days. Taking each dose on schedule and completing the full course gives PEP its best chance of working. Do not stop or change the medicine on your own, even if you feel well. Speak with us first if you miss doses, vomit after a dose, develop troublesome symptoms, or find it difficult to continue.

The most important practical points are:

• seek medical assessment immediately and start PEP within 72 hours if it is recommended;
• take every dose as prescribed for the complete 28-day course;
• tell your doctor about prescription medicines, over-the-counter products, supplements, alcohol, and recreational drugs;
• attend scheduled safety checks and follow-up HIV tests; and
• avoid new exposures and use appropriate prevention while follow-up is ongoing.

Side effects and medicine interactions

Current PEP medicines are generally manageable for most people, although side effects can occur. Reported effects include nausea, reduced appetite, diarrhoea or loose stools, tiredness, muscle aches, difficulty sleeping, and vivid dreams. The exact effects depend on the regimen and the individual. Many minor effects can be managed, but you should contact us if a symptom is persistent, severe, or worrying rather than discontinuing treatment yourself.

Drug interactions matter. Some prescription and non-prescription products can affect PEP medicines or be affected by them. Your kidney or liver health may also influence regimen selection or monitoring. Give your doctor a complete list of everything you take. If another clinician proposes a new medicine while you are on PEP, let them know about your PEP and check before starting it.

PEP can be considered during pregnancy or breastfeeding. This requires prompt individual assessment so that a suitable regimen can be selected and your broader care needs can be addressed.

Follow-up tests after starting PEP

A negative baseline HIV result only describes what the test can detect at that time; it cannot immediately exclude infection from the exposure that prompted your visit. Follow-up testing is therefore an essential part of PEP care. Evidence sources commonly describe repeat HIV testing around four to six weeks and again at three months, with the exact schedule determined by the test used, clinical guidance, and your circumstances.

You may also need follow-up kidney or liver tests to monitor medicine safety. If the exposure was sexual, testing for other sexually transmitted infections can be arranged at clinically appropriate times. Seek medical advice sooner if you develop symptoms, have a new exposure, cannot take the medicine consistently, or experience significant side effects.

While taking PEP and during follow-up, reduce the possibility of another exposure. Use condoms correctly and do not share needles or injecting equipment. A new exposure can change the assessment and testing timeline, so tell your doctor promptly if one occurs.

PEP and PrEP are different

PEP is emergency treatment started after a possible exposure. Pre-exposure prophylaxis (PrEP) is planned prevention taken before exposure for people with ongoing HIV risk. PEP should not be treated as a recurring substitute for PrEP or other prevention measures.

If you find that you need PEP repeatedly, or expect continuing exposure, discuss PrEP with us. Planning this transition before finishing PEP can help avoid gaps in protection. The right approach depends on your HIV test results, adherence, kidney health, pattern of exposure, and individual preferences.

Acting within the 72-hour window

An HIV exposure concern can be stressful, but the immediate decision is straightforward: obtain a professional risk assessment without delay. Do not wait for symptoms, because early HIV infection may not cause recognisable symptoms and PEP eligibility is governed by time. Bring the names or photographs of medicines you currently use and any reliable information about the exposure, but do not postpone attendance if those details are unavailable.

At Shim Clinic, we will assess your situation personally, explain whether PEP is appropriate, arrange relevant baseline tests, and provide a clear treatment and follow-up plan. PEP is time-sensitive, lasts 28 days when prescribed, and works best with early initiation and complete adherence. If the possible exposure happened within the last 72 hours, contact us now.

References

1. Shim Clinic
2. World Health Organization: HIV
3. US Centers for Disease Control and Prevention: Preventing HIV with PEP
4. MedicineSG

• HIV pep @ Wikipedia