Pharmacokinetic interactions between eperisone hydrochloride and aceclofenac: a randomized, open-label, crossover study of healthy Korean men.

BACKGROUND

Eperisone hydrochloride, a centrally acting muscle relaxant, is a calcium antagonist that causes vasodilation and antispastic actions. Aceclofenac, an anti-inflammatory analgesic and antipyretic drug, has similar efficacy and improved gastrointestinal tolerance compared with other nonsteroidal anti-inflammatory drugs, such as diclofenac. Although eperisone hydrochloride and aceclofenac are frequently coadministered, no published studies have reported on the pharmacokinetic interactions between these 2 drugs.

OBJECTIVE

The aim of this study was to investigate any pharmacokinetic interactions between eperisone hydrochloride and aceclofenac in healthy Korean men.

METHODS

This was a randomized, open-label, crossover study. Each participant was randomly assigned to 1 of 6 treatment sequences and received eperisone hydrochloride (3 doses of 50 mg each), aceclofenac (2 doses of 100 mg each), or both as a single dose with a 7-day washout period between each dose. Blood samples were collected ≤ 24 hours after dosing, and plasma eperisone hydrochloride and aceclofenac concentrations were determined using validated LC/MS-MS. Pharmacokinetic analyses were conducted using noncompartmental methods. A safety profile was determined using the measurement of vital signs, ECG, and clinical laboratory tests.

RESULTS

A total 24 of men were enrolled, and all completed the study. The geometric mean ratios (90% CIs) of the Cmax and AUC0-∞ values for eperisone were 1.18 (0.828-1.673) and 1.12 (0.836-1.507), respectively. The geometric mean ratios (90% CIs) of the Cmax and AUC0-∞ for aceclofenac were 0.93 (0.847-1.022) and 1.01 (0.979-1.036), respectively. A total of 7 adverse events were reported in 7 men. All adverse events were mild, and no significant differences were found between treatment groups.

CONCLUSION

No clinically significant pharmacokinetic differences exist between 150 mg eperisone hydrochloride and 200 mg aceclofenac when administrated as a monotherapy or in combination.