pharmacology: Spasmolytic drug

Spasmolytic drug: 

These drugs reduce abnormally elevated muscle tone that's spasm; without paralysis; without complete muscle paralysis relaxation, without loss strength of muscle

Spasmolytic agent don't ressemble Ach in the structure while both are competitive blocker.

All spasmolytic drugs are used orally; because these are highly potent compounds and unabsorbable when they are taken orally.

Spasmolytic don't act on neuromuscalar junction itself; but they are acting either:

• centrally on CNS 
• directly on muscle fiber

Drug acting on CNS centrally and spinal cord:

Diazepam:

• still used as sedative or hypnotic and some times as anticonvulsive effect
• its main effect is facilitated GABA amino gluetric acid mediated transmition 

Tizandine:

• act on spinal cord mainly
• clonidin like in their structure; used as anihypertensive 
• said to be an alpha 2 agonist

Drug acting on the muscle fiber:

Dantolene:

• act directly on the muscle fibe
• preventing Ca release from these muscle fiber; reducing the contraction or muscle tone.