PrEP is the abbreviation for pre-exposure prophylaxis. This is intended to prevent the transmission of an HIV infection during unprotected sexual contact with a possibly HIV-positive partner (according to study data 86-99%, depending on the accuracy of the application) if condoms are not used. In this case, the (HIV negative) partner takes TDF/ FTC before and after sexual contact, a drug that is also approved for HIV therapy in combination with other substances.
Since 1 September 2019, these drugs have been covered by the statutory health insurance funds for people with an increased risk of infection.
HIV PrEP prevents the HIV viruses from multiplying and spreading in the body and in the immune cells.
For the lasting benefit of PrEP, the continuous daily intake of one tablet of the combination active substance TDF/ FTC is recommended by the German-Austrian guidelines. The active substances are well accumulated in the anal and intestinal mucosa, which means that in the case of exclusively anal intercourse, study data suggest that sufficient protection is built up two days after the start of daily PrEP. The same is assumed for the penile mucosa. However, this has not yet been scientifically substantiated.
The vaginal mucosa does not absorb the active substances so well and also breaks them down again more quickly, so it is assumed here that a sufficiently high active substance level only exists after 7 days of intake before sexual contact.
In cases where anal intercourse is planned for a short time without regular intake of the medication (so-called occasion-related intake), the combination can also be taken in double dosage 2-24 hours before the planned sexual contact. The shortest possible and safest interval is 2 hours before intercourse. Continue to take one tablet daily until two days after the last sexual contact. Occasional use is not generally recommended, it is a so-called “off-label-use” of the medication. This method is not to be used for vaginal contact.
Before taking and prescribing PrEP, which may only be prescribed by doctors qualified to do so, regular and special blood tests are necessary. These include an HIV test and screening for hepatitis B infection as well as checking kidney function parameters and examinations for possible STIs such as syphillis, gonococci, hepatitis C and chlamydia or mycoplasma.
If an HIV infection is unknowingly present, resistance can develop during PrEP use, which should be avoided at all costs. Hepatitis B infections should also be checked before taking the medication, as otherwise undetected hepatitis B infections can flare up and develop dangerous courses when PrEP is discontinued.
Rarely, there are HIV virus strains that are resistant to components of the PrEP medication. In this case, an HIV infection can occur despite PrEP, as it then has no effect on the existing virus. Worldwide, there have only been a few such cases so far. These examinations should take place at regularly scheduled intervals, so it is important to have continuous medical care from doctors experienced in PrEP.
Please contact us if you are interested in PrEP or if you would like individual advice on possible side effects.