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Page 2 of 8 Guideline

The 2012 PrEP guideline was last updated in 2016. • Whilst TDF/FTC is available for all populations, TAF/FTC
The current (2020) guideline provides further options has so far only been shown to be efficacious in men and TG
1
regarding drug use and the practice of oral PrEP, including women. Studies in cisgender women are planned.
(1) broadened eligible groups to include pregnant and • Pre-exposure prophylaxis at this time is in the form of
breastfeeding women, (2) reduced clinical and health oral pills only, but topical rings and long-acting injectables
system barriers to simplify PrEP initiation and are under investigation. 27
administration (e.g. same-day PrEP), (3) broadened PrEP
delivery to include on-demand PrEP in MSM and TG
women, (4) provided updates of adverse events and relevant Who is pre-exposure prophylaxis for?
drug–drug interactions and (5) suggested parameters with Pre-exposure prophylaxis is an effective prevention option
which to measure PrEP rollout and success. We also for any sexually active person who might be exposed to HIV
introduce alternative oral antiretroviral (ARV) agents and through contact with HIV-infected body fluids (genital and
new modalities on the horizon. We present an updated blood). Pre-exposure prophylaxis is suitable for people of
lexicon for PrEP clients and users in Figure 1. any sex, gender and sexual orientation.

Quick facts on oral pre-exposure The WHO recommends that PrEP should be scaled up for
prophylaxis populations where the incidence of HIV is 3% or greater.
24
Although risk is unevenly distributed across sub-
At this time, PrEP is the daily use by the HIV-uninfected of oral populations and geographic areas in Southern Africa, a
TDF or tenofovir alafenamide (TAF)/Emtricitabine (FTC) very large number of sexually active people are exposed to
co-formulated with emtricitabine (TDF/FTC or F/TAF) or this degree of risk. Whilst many PrEP efforts have focused
variations of this, for example, TDF on its own on specific ‘high-risk’ or key population groups, at an
or co-administered with lamivudine (3TC) to prevent
HIV acquisition (transmission). The most commonly used individual client level, anyone who reports that he or she is
preparation and the one licensed in South Africa for oral PrEP at risk of HIV infection might benefit from PrEP. In these
is TDF/FTC. Pre-exposure prophylaxis has been shown to be cases, PrEP education should be provided and intervention
effective amongst a wide range of HIV-negative populations. should be offered.
There are other drugs and other routes of administration
under investigation, for example, a topical dapivirine vaginal On the contrary, the use of a risk scoring tool is not
ring and long-acting injectable cabotegravir. The registration recommended but rather that an accurate sexual history is
of TAF is currently under review in South Africa. These elicited from clients to identify sexual behaviours that justify
guidelines will be updated as new data become available : consideration of improved or enhanced HIV prevention
21
strategies. This is because risk scores fail when risk is not well
• Pre-exposure prophylaxis has a long history of
effectiveness in the setting of preventing vertical HIV judged and individual risk levels are dynamic; in addition,
transmission. Protective in utero foetal ARV drug levels no single risk score has been validated for generalised use.
are optimised prior to delivery (exposure). 23 Given the high ongoing rates of HIV transmission in South
• Consistent adherence to PrEP reduces the risk of HIV Africa and low current PrEP demand and no saturation in
21
transmission from sex by > 95%. 2 both the private and public sectors, people seeking PrEP
• For those at risk, daily PrEP has been confirmed to be should be encouraged to initiate PrEP, provided that they are
effective in the prevention of sexual and injecting drug sexually active and there is a reasonable risk that they might
use HIV transmission. Where adherence is suboptimal, be exposed to HIV (see Table 1).
PrEP is less effective (unreliable) as protective drug (ARV)
levels at the time and site of exposure may be too low. Differing pharmacokinetic (PK) data play a role in different
Daily use is the most dependable way to ensure recommendations for dose frequency in different populations.
effectiveness. 24 Tissue drug concentrations in genital and anal mucosa vary
• Condom use is still recommended as PrEP does not with higher levels and steady states reached more rapidly in
protect against other sexually transmitted infections anal compared with vaginal mucosa. Pharmacokinetic
28
(STIs), such as syphilis, chlamydia and gonorrhoea. modelling studies have suggested that fewer doses may be
• Pre-exposure prophylaxis has no contraceptive effect. required to reach effective concentrations in anal compared
The drugs used in PrEP do NOT interact with with vaginal mucosa. This has led to three recommendations
hormonal contraception. that depend on whether exposure is via vaginal (heterosexual
• Pre-exposure prophylaxis is safe to take when pregnant sex) or anal mucosal routes:
or breastfeeding. 19,25
• On-demand PrEP (for MSM and TG women only): Two • Pre-exposure prophylaxis where the HIV exposure is via
pills are taken 2–24 h before sex. If sex occurs, the vaginal mucosa should be dosed daily.
individual who is or is presumed to be HIV-uninfected • Pre-exposure prophylaxis where the HIV exposure is via
follows up with one pill per day for 2 days after sex. 26 vaginal mucosa may require up to 7 days of dosing before
• Pre-exposure prophylaxis is generally well tolerated. being fully effective.
Occasional side effects include nausea, bloating and/or • On-demand PrEP is not recommended where exposure is
headaches in approximately one in 10 users. via vaginal mucosa.

http://www.sajhivmed.org.za 67 Open Access