Tenofovir Disoproxil Fumarate + Emtricitabine = Unknown or no reaction

Effect on Concentration

Tenofovir Disoproxil Fumarate
No change
Applies within class?
No
Emtricitabine
No change
Applies within class?
No

Pharmacologic Effects

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

Interaction History

N/A

Last Updated 19-Jul-2018

Summary

Sources

Tenofovir Disoproxil Fumarate versus Emtricitabine ^

Study Design

This was a phase 1, open-label randomized 3-way crossover study conducted at a single study center to evaluate the steady state pharmacokinetics of emtricitabine and tenofovir DF when administered alone and together in healthy volunteers. Eighteen eligible adults were randomized to receive each of three treatments over a 21 day period. Treatment one was emtricitabine 200 mg in the morning for seven consecutive days. The second treatment was tenofovir DF 300 mg administered every morning for seven consecutive days. The third treatment was a combination of emtricitabine 200 mg and tenofovir DF 300 mg administered simultaneously for seven consecutive days. There was no washout interval between treatments. The order in which each patient received the treatments was determined by randomization

Study Results

Drug Cmax (mcg/ml) AUC (mcg*h / ml) Cmin (mcg/ml) Tenofovir Alone 0.279 2.84 0.054 Tenofovir (with Emtricitabine) 0.288 2.8 0.054 Emtricitabine Alone 1.77 10.2 0.064 Emtricitabine (with Tenofovir) 1.69 10.7 0.075 The GMR of emtricitabine plus TDF versus emtricitabine alone for emtricitabine AUC, Cmax and Cmin were 1.07 (100% - 114%), 0.96 (87%-106%), and 1.2 (112%-129%), respectively, which were all within the 70% - 143% no effect boundary for a conclusion of no clinically significant differences in emtricitabine pharmacokinetics between treatments. The GMR of tenofivir plus emtricitabine versus tenofovir DF alone for tenofovir AUC, Cmax and Cmin were 1 (92%-109%), 1.03 (95%-111%), and 1.02 (92%-113%) respectively.

Study Conclusions

In an open label, three period cross over study in healthy volunteers, when emtricitabine and tenofovir DF were coadministered, no significant effect on steady state Cmax or AUC was observed for either drug relative to values obtained when administered alone for 7 days. The authors concluded that concomitant administration with of these two agents did not affect the pharmacokinetics of either drug.

References

Blum MR, Chittlick GE, Begley JA, Zong J. Steady‐state pharmacokinetics of emtricitabine and tenofovir disoproxil fumarate administered alone and in combination in healthy volunteers. Journal Of Clinical Pharmacology. 2007; 6: 751-759.