You should consider PEP if you have been exposed to the bodily fluids (such as semen, vaginal fluids, blood, etc.) of an HIV-positive person, or even when you’re not able to rule that possibility out. If you’re not sure about the HIV status of your partner, it’s best to make a decision based on the activity and possible exposure you had, so please consult with a specialist at KARADA Internal Medicine Clinic. Here is a list of possible exposures, from higher to lower risk of HIV transmission: receptive anal intercourse > insertive anal intercourse > receptive penile-vaginal intercourse > insertive penile-vaginal intercourse > oral intercourse.
[Source] http://www.cdc.gov/hiv/policies/law/risk.html

While there is no clear research data answering this question, studies have shown that the probability of success in preventing infection decreases over time. Therefore, it is extremely important to start taking the medication as soon as possible. Preventing infection is crucial, as there are currently no medications available to cure HIV. Chances are you are now reading this because you feel at risk; please note that this is the only treatment currently recommended by medical professionals. Although the medication is expensive and its effectiveness may decrease over time, it might be your only option for preventing infection, you can consult with a specialist at our clinic before starting the actual treatment, so please reach out to us.

Although limited to reports within certain occupations in the US, there have been no cases of HIV infection established after the introduction of PEP treatment since 1999, except for one single case (details unclear, under special circumstances). Similarly, in the UK, there have been no reports of infection during the same period. Considering there were hundreds of confirmed and suspected cases of infection before, one can get an idea about the effectiveness of this treatment.

Individuals infected with the hepatitis B virus may experience worsening of hepatitis B if they stop taking this medication. If you have hepatitis B, please consult with a specialist at KARADA Internal Medicine Clinic. Additionally, it is crucial to check whether you are not already infected with HIV before starting PEP, as it could impact your future HIV treatment.

Generic drugs generally contain the same active ingredients as new drugs. New drugs require significant investment in research and development and are priced to cover these costs, along with a period for evaluating efficacy and safety after release. On the other hand, the development costs for generic drugs are said to be about 1% to 1‰, allowing them to be offered at a lower price but with the same effectiveness. However, you should be aware that Japan’s Relief System for Health Injuries does not cover any side effects that may occur from imported PEP/PrEP generic drugs.

Confirming HIV infection
It is necessary to rule out the possibility of already being infected before starting treatment. While PEP and Prep are preventive measures, they are not effective for HIV-positive patients, who need to undergo a different treatment. Furthermore, taking PrEP or PEP while being unknowingly HIV-infected can increase the likelihood of creating a virus that is resistant to future medication.

Possible side effects
It is also necessary to check kidney function before starting medication. It’s important to assess whether undergoing treatment is safe and whether there are (although rare) any kidney function impairments after starting medication.