Mechanism of Action of Eperisone
Eperisone is a centrally acting muscle relaxant that works through multiple mechanisms including inhibition of mono- and multisynaptic reflexes in the spinal cord, regulation of blood supply to skeletal muscles, and calcium channel blocking effects.
Primary Mechanisms
- Eperisone inhibits gamma-efferent firing in the spinal cord, reducing both mono- and multisynaptic reflexes, which decreases muscle tone and relieves muscle spasm 1
- It acts as a calcium channel antagonist, blocking voltage-dependent calcium influx at smooth muscle cell membranes, which contributes to its muscle relaxant and vasodilatory effects 2
- Eperisone improves blood circulation to skeletal muscles through vasodilation, which is particularly important since muscle contracture can compress small blood vessels and induce ischemia that leads to pain 1
Pharmacokinetic Properties
- Eperisone is rapidly absorbed after oral administration with a peak plasma concentration (Tmax) reached at approximately 1.6 hours, consistent with its fast-onset muscle relaxant activity 3
- It has a short biological half-life of about 1.87 hours and undergoes rapid elimination from the body 3
- The drug does not accumulate in the body with repeated dosing, making it suitable for both short-term and long-term use 3
Advantages Over Other Muscle Relaxants
- Unlike many other centrally acting muscle relaxants, eperisone has minimal adverse effects on the central nervous system (CNS), such as drowsiness or sedation 1
- This favorable side effect profile is due to its more selective action on spinal reflexes without significant CNS depression 1, 4
- The combination of muscle relaxant properties and vasodilatory effects makes eperisone particularly effective for conditions involving both muscle spasm and pain 1
Clinical Applications
- Eperisone is effective in treating acute musculoskeletal spasm associated with low back pain 4
- It is also used in the management of muscle contractures and spasticity 3
- The drug shows significant improvement in reducing both spontaneous and provoked pain, as well as progressive decontracture of spinal muscles 1
Related Compounds
- Silperisone is a related compound with similar centrally acting muscle relaxant properties, though it has a longer duration of action (elimination half-life of 12-16 hours in humans) 5
- Both eperisone and silperisone are similar to tolperisone in their mechanism of action, though with some differences in potency and pharmacokinetic properties 5
Precautions
- The Mayo Clinic recommends holding eperisone on the day of surgical procedures to avoid potentiating anesthetic agents 6
- The drug is contraindicated in patients with significant hepatic or renal dysfunction 6
- Patients with hepatic or renal impairment may have altered eperisone metabolism, potentially increasing interaction risks 6