The Potential Effect of Using the Cockcroft-Gault Method on Tenofovir-Associated Renal Impairment Reports and on Clinical Decisions Regarding Tenofovir Use in Individual Patients: Implications for the Future

Francis Kalemeera,Amos Massele,Brian Godman,Ester Naikaku,Marike Cockeran,Dan Kibuule,Mwangana Mubita

doi:10.4172/2329-8731.1000170

Francis Kalemeera, Amos Massele + Show 5 more

Open Access

https://doi.org/10.4172/2329-8731.1000170

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Abstract

Introduction: In Namibia, the Cockcroft-Gault (C-G) method is recommended for monitoring renal function in HIV patients receiving Tenofovir Disoproxil Fumarate (TDF)-containing Combination Antiretroviral Therapy (cART). However, there are concerns with the potential over-reporting of TDF-associated renal impairment. Methods: Retrospective study comparing the renal function of patients receiving 2nd line cART with either C-G or Chronic Kidney Disease-Epidemiology (CKD-EPI) methods. Results: 71 patients were included. The majority (62%) received TDF-containing 1st line ART. All received 2ndline cART containing TDF/Lamivudine (3TC)/Zidovudine (AZT) and LPV/r. Before switching to 2nd-line cART, 40.8% and 8.5% had abnormal eGFR according to C-G and CKD-EPI methods respectively. During 2nd-line cART, 47.9% and 7% of patients had abnormal eGFR by C-G and CKD-EPI methods, respectively, and 4.1% and 2.8% respectively experienced a decline in eGFR. There was a significant lack of agreement between the two methods. Conclusion: The C-G method has the potential to report more cases of TDF-associated renal impairment. Consequently, national guidelines in Namibia and other pertinent countries should be reviewed if this is the recommended method for monitoring renal function.

Highlights

In Namibia, the Cockcroft-Gault (C-G) method is recommended for monitoring renal function in Human ImmunoDeficiency Virus (HIV) patients receiving Tenofovir Disoproxil Fumarate (TDF)-containing Combination Antiretroviral Therapy
The computations of eGFR were based on the last recorded SeCr measurements before patients were switched to second-line Combination Antiretroviral Therapy (cART) and the last SeCr measurements during second-line cART
Our study has shown that the wrong eGFR computations by the C-G method may not influence clinical decisions at the individual patient level, at least not within 2.6 years of second-line cART

Summary

Introduction

In Namibia, the Cockcroft-Gault (C-G) method is recommended for monitoring renal function in HIV patients receiving Tenofovir Disoproxil Fumarate (TDF)-containing Combination Antiretroviral Therapy (cART). Sub-Saharan Africa, being the most affected region of the world with the HIV pandemic, has gained tangible benefits from the use of combination antiretroviral therapy (cART) [3,4,5] Despite these tangible benefits, ARV medicines are associated with adverse drug reactions, the impact, incidence, and prevalence of which is not completely measured at the time these medicines are approved for clinical use especially if patients have greater co-morbidities than those enrolled into Phase III trials [6]. In Namibia, any TDF dosage adjustments or withdrawals were generally prompted by the estimated CrCl via the C-G formula

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