MED305_Spasmolytics.pdf

MED305 Spasmolytics and miscellaneous drugs Said KALKIŞIM, MD PhD School of Medicine, Department of Medical Pharmacology [email protected] muscle relaxants neuromuscular blockers Spasmolytics and Antispasmotics In surgeries and intensive care units To reduce muscle spasm and pain Spa...

MED305 Spasmolytics and miscellaneous drugs Said KALKIŞIM, MD PhD School of Medicine, Department of Medical Pharmacology [email protected] muscle relaxants neuromuscular blockers Spasmolytics and Antispasmotics In surgeries and intensive care units To reduce muscle spasm and pain Spasmolytic and antispasmodic drugs • Spasmolytics → motor neuron-induced spasms • Antispasmodics → Peripheral spasms • Spasticity, manifested by temporary or permanent involuntary contraction of skeletal muscles and tension in reflexes     • Cerebral Palsy Spinal injury Multiple sclerosis Cerebrovascular accident Reflex arc modifying drugs can reduce this response in the muscles. Contraction of flexor muscles after spasticity Diazepam • Benzodiazepine group drug. • It enhances the GABAA effect in the CNS. The GABAA receptor exerts an inhibitory effect by providing the passage of Cl- ion to the nerve cell. • It also has a sedative effect. Dantrolene • Binds to ryanodine receptors, inhibiting them. Thus, the output of Ca++ from the sarcoplasmic reticulum is suppressed • It is used in the treatment of malignant hyperthermia (IV) • The oral form can also be used as a general-purpose spasmolytic. Baclofen • GABAB receptor agonist. • It makes hyperpolarization in presynaptic and postsynaptic neurons. (Cl- entry into the cell) • Compared to diazepam, it has less muscle relaxant effect and sedation. • It can be administered intrathecally in cases with severe muscle spasms. Tizanidine • α2 sympathetic receptor agonist. • The presynaptic receptors of this receptor in neurons have a sympatholytic effect. • However, tizanidine exerts a myorelaxant by an unknown mechanism • Among other α2 agonists, only tizanidine is used for this purpose because it exerts this effect at doses with less cardiovascular effects than other α2 agonists. • It is thought to inhibit the presynaptic and postsynaptic nerves located in the spinal cord. Botulinum Toxin • It is the most potent poison known. The lethal dose in men is 1.3-2.1 ng/kg. • It inhibits the release of acetylcholine (ACh) from vesicles. For this reason, ACh cannot be released into the synaptic space and Ach-mediated effects cannot be observed. • In cases with tic disorder or spasm • In wrinkle removal operations for aesthetic purposes • Extraocular muscles in the treatment of strabismus • In the treatment of excessive sweating • Administered locally. Clostridium botulinum Antispasmodics • carisoprodol, chlorphenesin, chlorzoxazone, cyclobenzaprine, metaxalone, methocarbamol, orphenadrine, and thiocolchicoside • It is used against local muscle spasms due to trauma • Combined use with painkillers • Mechanisms of action are not clear  Thought to be effect on CNS • AE: Sedation, muscle weakness • Care should be taken with alcohol