PrEP or pre-exposure prophylaxis is a combination of anti-viral medications which has to be taken in advance before engaging in sexual activities/other activities that could potentially transmit HIV to a person already not infected with HIV. People who are HIV negative are eligible to take PrEP to avoid getting HIV, from a potential high risk exposure.
PrEP is known to be very safe, if taken under guidance of doctors.
There are different ways of initiating PrEP in men who have sex with men. Regular / daily PrEP has shown to give best results.
The PrEP medicines must be taken strictly under medical guidance.
A. Daily dosing regimen/ Regular PrEP
- One pill has to be consumed at the same time everyday starting 7 days prior to one’s date of planned exposure. This singular daily dosage at the same time, every day, has to be continued, as long as one is sexually active under high risk conditions.
- Two pills have to be consumed together on full stomach at the same moment, 2-24 hours before the time of one’s planned exposure and then has to be continued as a singular dosage (one pill) at the same time, on full stomach, every day, as long as one is sexually active or unless one feels that the high risk factors to contract a potential HIV infection have come down for oneself.
B. On demand PrEP
Two pills have to be consumed 2-24 hours prior to the time of one’s planned exposure and then considering, the day of exposure as day 0, the medication has to be continued as singular dosage on day 1 and day 2 and then can be stopped. In other words, the one pill has to be taken daily for 2 days after the exposure has occurred.
The reason for starting PrEP as singular dosage daily, 7 days prior to the date of planned exposure or 2 pills together at same moment, 2-24 hours prior to one’s time of planned exposure, is that it takes 7 days of daily singular dosage of PrEP medications or 2-24 hours with 2 pills consumed together at the same moment; to reach the bioactive concentration levels in the anorectal tissue so that if at all there is an entry of HIV during penp-anal intercourse, it can be checked by the active levels of PrEP in the ano-rectal tissue then and there, itself.
However, on-demand PrEP regimen is not encouraged over the methods of daily dosage regimen as frequent or irregular cycles of initiation and stoppage of PrEP medications can lead to PrEP failure where in a person may turn seropositive for HIV despite consuming PrEP owing to the phenomenon of drug resistance, which is most commonly precipitated due to frequently or irregularly starting and stopping PrEP.
Similarly, the method of initiating PrEP in females is different. Females, however, don’t have the option of starting PrEP on an on-demand basis as there is no research data available, in this regard. Thus, females have only the option of initiating PrEP as daily singular dosage. One pill has to be consumed, at the same time every day, on full stomach, starting from 20 days prior to one’s date of planned exposure and then continuing this singular daily dosage at the same time, on full stomach, every day, as long as one is sexually active or unless one feels that the high risk factors to contract a potential HIV infection, have come down for oneself. Just like for the men who have sex with men, the reason for having such a regimen in women is that it takes 20 days of daily singular dosage of PrEP medications to reach the bioactive concentration levels in the cervico-vaginal tissue so that if at all there is an entry of HIV during peno-vaginal intercourse, it can be checked by the active levels of PrEP in the cervico-vaginal tissue then and there, itself.
PrEP has to be taken strictly under medical guidance, after doing the required tests and understanding the risks of taking PrEP.