Page 79 - HIVMED_v21_i1.indb

Page 6 of 8 Guideline

Finally, the topical dapivirine vaginal ring has just been peri-menopausal women and those with a history of
recommended by the European Medical Agency as a PrEP fragility fractures), the use of TAF or episodic TDF (to reduce
intervention for women unable to safely utilise oral PrEP. exposure) could be considered.
This preventive tool was shown to reduce HIV acquisition
by about 30% in women at risk of HIV acquisition in two Hepatitis B: Tenofovir disoproxil fumarate is also an
44
RCTS conducted in Africa. antiviral treatment for hepatitis B. For this reason, screening
for hepatitis B surface antigen is recommended prior to
Updates to adverse events and drug–drug starting PrEP, but should not prevent PrEP start. Hepatitis
interactions B infection is also not a contraindication for PrEP use in
Adverse events individuals who would benefit. Caution when stopping
Tenofovir disoproxil fumarate and TAF are safe and well- PrEP may be required in those who are hepatitis B surface
tolerated drugs. Side effects do not occur in 90% or more antigen positive. Rebound of hepatitis B virus resulting
clients who start PrEP. Initial minor side effects including in liver injury has been described in the setting of ART and
headache and gastrointestinal upset (i.e. diarrhoea, nausea not PrEP but remains a theoretical concern. Hepatitis B
and loss of weight) may be experienced in up to 10% of vaccination is recommended for those who are hepatitis
people taking PrEP, but are self-limiting, with resolution surface antigen negative.
within 2–3 weeks. These can be managed symptomatically.
3
Tolerance improves over time. Drug resistance: Drug resistance mostly occurs when PrEP
is initiated at a time when the client is acutely HIV infected
Renal toxicity: A creatinine clearance (CrCl) test is and is seroconverting. During these times, viral replication
recommended at the time of PrEP commencement to occurs rapidly in the blood. Pre-exposure prophylaxis drug
exclude asymptomatic renal disease but is not essential in concentrations are still suboptimal. Clients who seroconvert
well individuals under the age of 40 years and should not should stop PrEP use immediately and initiate ART as soon
delay PrEP start. Tenofovir may cause a 5 mL/min – 6 mL/ as possible. Monitoring of ART should follow adult
min reduction in CrCl in the first few months of use and if treatment guidelines.
this prompts a PrEP pause, PrEP may be re-introduced in
most cases without further problems. Drug–drug interactions
Transgender women on feminising hormonal treatment
In pregnant women, individuals > 40 years of age, those with were thought to be in danger of drug–drug interactions
a chronic disease and those using concomitant medications, with reduced efficacy of PrEP; however, a recent study
creatinine should be drawn the same day as PrEP start has shown this is not the case. 45
(results can be communicated later) and repeated at months
6 and 12. More frequent monitoring of renal function may be Tenofovir disoproxil fumarate is largely eliminated by the
required for people with chronic diseases such as kidneys. There are few drug interactions of note, but TDF
hypertension and diabetes, as per the plan for that should be used with caution with medications that cause
comorbidity. Tenofovir disoproxil fumarate should not be renal toxicity (see Table 3).
commenced if the CrCl is < 50 mL/min, and should be
stopped if the CrCl declines below 50 mL/min. The client Conclusion
can re-test within 1 month to establish if their CrCl changes
and can start PrEP then. Where renal toxicity is an issue, We expect guidelines to be updated on a regular basis in
TAF/FTC may be considered as an alternative agent because line with ongoing research on vaginal rings, new drugs
of its renal sparing properties (see Table 2). (including TAF), new regimens and injectable PrEP.
South Africa is involved in several clinical trials.
Bone mineral density: There is evidence for bone density Longer term and, on-demand modalities are compelling
loss with long-term use of TDF. For those with risk factors alternatives for individuals who either do not want to
for reduced bone mineral density (BMD) (e.g. adolescents, take a daily pill and, or want to take PrEP intermittently.
people using recreational drugs such as amphetamines, Emerging modalities such as vaginal films, microneedles
people > 60 years of age, with known low BMD, post- and and subdermal implants have numerous advantages but

TABLE 2: Creatinine monitoring with tenofovir disoproxil fumarate pre-exposure prophylaxis.
Variable At PrEP start At PrEP follow-up
Well individual, ≤ 40 years Recommended, not essential Not required
> 40 years Recommended 6 and 12 months
Pregnant Recommended 6 and 12 months; not required after pregnancy if
≤ 40 years
Comorbidities Recommended 6 and 12 months
Concomitant chronic medication Recommended and essential or contra-indicated if nephrotoxic 6 and 12 months/contraindicated
concomitant medication
PrEP, pre-exposure prophylaxis.

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