Drug safety evaluation of oral tenofovir disoproxil fumarate-emtricitabine for pre-exposure prophylaxis for human immunodeficiency virus infection

Evaluation of pharmacokinetics of Tenofovir Alafenamide (TAF) and Tenofovir Disoproxil (TDF) in pregnant and postpartum women in South Africa: PrEP-PP PK study

BACKGROUND

There are few data on tenofovir-diphosphate (TFV-DP) concentrations in pregnant and postpartum women on Tenofovir Disoproxil Fumarate-Emtricitabine (TDF-FTC) or Tenofovir Alafenamide-Emtricitabine (TAF-FTC).

METHODS

Eligible pregnant women were randomized to TDF-FTC or TAF-FTC and followed for 16 weeks (8-weeks pregnant, 8-weeks postpartum) with weekly collection of dried blood spot (DBS) and 4-weekly peripheral blood mononuclear cells (PBMC). PrEP dosing was observed daily via asynchronous videos sent via cell phone. We report geometric means (GM) and their ratios (GMR) with 95% confidence intervals (CIs) for TFV-DP in PBMC and DBS from pregnancy and postpartum.

RESULTS

We enrolled N = 39 participants (n = 19 TDF-FTC, n = 20 TAF-FTC): median age was 28 years (IQR:25-34); median gestational age was 24-weeks (IQR:21-28). For TDF-FTC, TFV-DP DBS concentrations at 8-weeks did not differ significantly between pregnancy (GM: 675; 95%CI:537-849) and postpartum (GM: 583; 95%CI:471-722; GMR-TDF = 1.16; 95%CI:0.74-1.80). For TAF-FTC, TFV-DP DBS concentrations at 8-weeks were 44% higher in postpartum (GM: 1199; 95%CI:929-1549) versus pregnancy (GM: 832; 95%CI:751-922; GMR-TAF = 1.44; 95% CI: 1.01-2.06). In PBMC analysis of TDF-FTC, 8-week median TFV-DP (pmol/10^6 cell) was 71 (IQR 44-112) in pregnancy and 73 (IQR 50-102) in postpartum (GMR = 1.04; 95%CI:0.44-2.44). In TAF-FTC, median PBMC at 8-weeks was 580 (IQR:341-985) in pregnancy and 666 (IQR:396-1123) in postpartum (GMR = 1.15; 95%CI:0.30-2.49).

CONCLUSION

TFV-DP concentrations were overall lower during pregnancy than postpartum for TAF-FTC. We found high concentrations of TFV-DP in PBMC in pregnancy and postpartum on TAF-FTC, suggesting PrEP efficacy is maintained. Efficacy and safety studies are warranted to evaluate TAF-FTC for PrEP in pregnant and postpartum women.

Knowledge, Attitudes and Practices Regarding Pre-Exposure Prophylaxis (PrEP) in a Sample of Italian Men Who Have SEX with MEN (MSM)

BACKGROUND

Pre-exposure prophylaxis (PrEP) is suitable for high human immunodeficiency virus (HIV)-infection risk people, foremost among whom are males who have sex with other males (MSM). This study evaluated knowledge, attitudes and practices regarding PrEP in a sample of Italian MSM, in order to hypothesize strategies to implement PrEP awareness and use. No previous study has assessed this issue; Methods: An online survey was given to an opportunistic sample of Italian MSM. The questionnaire investigated sexual behaviour and habits, HIV/acquired immune deficiency syndrome (AIDS) knowledge and PrEP awareness, attitudes and practices. Univariable and multivariable logistic regressions were conducted to identify factors associated with PrEP knowledge; Results: A total of 196 MSM participated in this survey. Overall data showed that 87.2% of participants knew what PrEP is, but only 7.5% have ever used it. The main reason for not using PrEP was the cost of the therapy (26.9%). The principal source of PrEP information was the Internet (68.4%). Being regularly tested for HIV was significantly associated with PrEP knowledge (adjusted odds ratio (AdjOR) = 3.16; confidence interval (CI) = 1.06-9.29); Conclusions: Knowledge regarding PrEP was well established, but PrEP use was not equally widespread. It is necessary to improve research on PrEP usage in order to PrEP access to be granted.

Health Profession Students' Awareness, Knowledge, and Confidence Regarding Preexposure Prophylaxis: Results of a National, Multidisciplinary Survey

BACKGROUND

Preexposure prophylaxis (PrEP) is a highly effective, pharmacologic method of HIV prevention. Despite its safety and efficacy, PrEP prescription remains low in those patients who are at highest risk for HIV infection. One possible reason for this may be the lack of inclusion of PrEP and HIV prevention discussions within the curricula of health professions education.

METHODS

An online survey was administered to a cross-sectional sample of future prescribers (osteopathic/allopathic medical and physician assistant students), future nurses, and future pharmacists (n = 2085) in the United States between January and July 2019 to assess and compare awareness of PrEP, PrEP education, PrEP knowledge, and confidence in 2 areas related to PrEP.

RESULTS

We show that, overall, awareness of PrEP is high among future health care providers (81.6%), with the future pharmacists reporting the greatest awareness (92.2%; P < 0.001) and more commonly reporting PrEP education (71.0%). Students had mixed knowledge of PrEP, with future pharmacists reporting the highest knowledge of PrEP. Approximately 30% of students in all disciplines reported having low confidence counseling a patient about PrEP and low confidence educating a colleague about PrEP. Knowledge of PrEP was a significant predictor of confidence counseling a patient about PrEP (P < 0.001) and educating a colleague about PrEP (P < 0.001).

CONCLUSIONS

This study identifies opportunities to improve and incorporate evidence-based strategies for educating future health care providers about PrEP for HIV prevention within health professions curricula.

Assessing the Potential for Nurse-Led HIV Pre- and Postexposure Prophylaxis in Ontario

BACKGROUND AND PURPOSE

HIV prevention efforts in Ontario require increased implementation of strategies including post- and pre-exposure prophylaxis. Access to these interventions could be improved by their provision through nurse-led models of care. We assessed nurses' readiness to deliver these interventions using a behavioral change framework.

METHODS

We distributed an online survey to nurses in every Ontario sexual health clinic, HIV clinic, and community health center between March-June 2018, to determine the level of support for nurse-led postexposure prophylaxis/pre-exposure prophylaxis; we also explored nurses' "capabilities," "opportunities," and "motivations" for providing postexposure prophylaxis/pre-exposure prophylaxis.

RESULTS

Overall, 72.7% of respondents supported implementation of both nurse-led postexposure prophylaxis and pre-exposure prophylaxis. More experienced nurses were less likely to support nurse-led postexposure prophylaxis and pre-exposure prophylaxis (adjusted odds ratio = 0.55 per decade nursing, 95% confidence interval (0.37, 0.82)). Nurses reported a high degree of knowledge of topics related to postexposure prophylaxis/pre-exposure prophylaxis, with the exception of creatinine interpretation.

CONCLUSIONS

Ontario nurses report high levels of support for nurse-led postexposure prophylaxis and pre-exposure prophylaxis and are well positioned to provide these interventions. Targeted education and implementation efforts are needed to engage these nurses in postexposure prophylaxis and pre-exposure prophylaxis delivery.

Impact of pharmacogenetics and pregnancy on tenofovir and emtricitabine pharmacokinetics

AIM

Treatment and prevention of mother-to-child transmission of HIV in pregnancy utilizes tenofovir (TFV) and emtricitabine (FTC) as NRTI backbone in combination with a third agent from a different class. We hypothesized that combined effect of pregnancy and pharmacogenetics significantly changes TFV and FTC pharmacokinetics (PK). Therefore, this study aims to evaluate the role of SNPs of transporters (ABCC2 and ABCC4) on TFV and FTC PK during pregnancy.

METHOD

61 pregnant or postpartum women on TFV and FTC were selected from a group of pregnant and postpartum Nigerian women and both SNPs and drug levels were evaluated.

RESULTS

Pregnancy decreases TFV plasma concentration by 26% (log₁₀ β = -0.131 [-0.228, -0.034; p = 0.009] at median [range] time-point postdose 14 [7-18.5h]). FTC concentration in individuals with ABCC2 12:g.154962860T>C TT genotype were one- to twofold higher than heterozygous (CT) and homozygous (CC) women. All other evaluated SNPs were not significant.

CONCLUSION

Pregnancy decreased TFV concentration and significant relationship was found between FTC and ABCC2 12:g.154962860T>C wild-type allele. However, the interplay between pregnancy and pharmacogenetics on TFV and FTC PK is unclear but require further evaluation.