| SHORT COMMUNICATION
|Year : 1995 | Volume
| Issue : 3 | Page : 183-185
Rifampicin pretreatment reduces bioavailability of diclofenac sodium
Kumar J Surya, Mamidi NVS Rao, T Chakrapani, DR Krishna
Diclofenac sodium 100 mg (2 x 50 mg enteric coated tablets) alone and in combination with rifampicin 600 mg as a single dose (group I and group II respectively) was administered to six healthy human volunteers in a cross over design. In the second study diclofenac sodium 100 mg was administered after a six day treatment with rifampicin 450 mg daily (Group Ill). Plasma concentrations of diclofenac were determined during a 8 hour period following drug administration. The mean peak plasma concentrations (Cmax) were 5.28, 6.68 and 2.99 fig/ml, time taken to reach. the peak (Tmax) were 3.17, 3.25 and 2.5 hrs and area under curve[AUC(0-()] were 14.17, 13.74 and 4.63 ug.hr/ml in the groups I, II and Ill respectively. Statistically a significant difference was observed in Cmax , AUC(0-() (P < 0.01) and Cl/f (P < 0.05) of diclofenac sodium when administered after six days treatment with rifampicin. However, there was no difference in pharmacokinetic parameters when diclofenac was administered with rifampicin as a single dose.
Kumar J Surya
Source of Support: None, Conflict of Interest: None