Tenofovir Disoproxil Fumarate + Diclofenac = Precautionary

Effect on Concentration

Tenofovir Disoproxil Fumarate
Increase
Applies within class?
No
Diclofenac
Unknown
Applies within class?
No

Pharmacologic Effects

Tenofovir Disoproxil Fumarate
Effect
N/A
Applies within class?
No
Diclofenac
Effect
N/A
Applies within class?
No

Interaction History

N/A

Last Updated 22-Nov-2022

Summary

The investigators indicated that diclofenac may increase TFV-associated nephrotoxicity by increasing concentration of TFV in the proximal tubular cells as a consequence of interaction between diclofenac and TFV. Therefore, diclofenac should be used with caution in patients on TFV therapy, especially in those with hypophosphataemia. While studies have not assessed the coadministration of other NSAIDS, such as ibuprofen and naproxen, recommend cautious use of the minimum effective dose of any NSAID in a patient already taking tenofovir.

Sources

Tenofovir disoproxil fumarate vs diclofenac ^

Study Design

This study is a retrospective analysis of all patients from the Frankfurt HIV Cohort who had prescriptions for diclofenac between 2008 and 2012. Among the 89 patients with diclofenac use, 61/89 (68.5%) were receiving tenofovir disoproxil fumarate (TFV), whereas 28/89 (31.5%) were on a TFV- sparing combination antiretroviral therapy (cART).

Study Results

13 patients (14.6%) developed acute kidney injury (AKI) shortly after initiating diclofenac. AKI occurred exclusively in TFV-treated patients who previously had stable renal function. All cases were found to have newly developed proximal tubule damage, such as normoglycemic glycosuria and hypophosphatemia. In contrast, Diclofenac did not affect renal function in patients not on tenofovir; patients receiving diclofenac exhibited no change in renal function while receiving tenofovir-sparing combination ART. In univariate analysis, risk factors for AKI were TDF-containing cART (P = 0.0076) and pre-existing hypophosphataemia (P = 0.0086).

Study Conclusions

References

M Bickel, P Khaykin, C Stephan, K Schmidt, M Buettner, K Amann, T Lutz, et al. Acute kidney injury caused by tenofovir disoproxil fumarate and diclofenac co-administration. Hiv Medicine. 2013; 10: 633-638.