Info-graphic on skeletal muscle relaxants.

1. SKELETAL
MUSCLE
RELAXANTS
D R . R A J P U S H PA L A B H

2. DEFINITION
• SKELETAL MUSCLE RELAXANTS ARE DRUGS THAT ACT
PERIPHERALLY AT NEUROMUSCULAR JUNCTION/MUSCLE
FIBRE ITSELF OR CENTRALLY IN THE CEREBROSPINAL AXIS TO
CAUSE PARALYSIS OR REDUCE THE MUSCLE TONE.

3. NEUROMUSCULAR JUNCTION

6. NEUROMUSCULAR RECEPTOR

7. MECHANISM OF ACTION
• NON DEPOLARISING BLOCK(COMPETITIVE BLOCK)
• DEPOLARISING BLOCK

8. NON DEPOLARSING BLOCK

9. DEPOLARISING BLOCK
• THEY DEPOLARIZE MUSCLE END PLATES BY OPENING Na⁺ CHANNELS(i.e., STIMULATION)
AND PRODUCES TWITCHING AND FASCICULATIONS.
• THIS STIMULATION IS TRANSIENT AND LONG LASTING WHICH LEAD TO REPETITIVE
EXCITATION OF MUSCLE FIBRE(CAUSES SUSTAINED CONTRACTION).
• THESE DRUGS DO NOT DISSOCIATE FROM RECEPTOR AND ARE NOT HYDROLYSED BY
AChE.

10. DEPOLARISING BLOCK
• CHOLINESTRASE
INHIBITOR WILL
INTENSIFY THE
RESPONSE TO SCh
DURING PHASE 1
BLOCK.
• THEY MAY
REINITIATE MUSCLE
CONTRACTION IF
ADMINISTERED
DURING LATE
PHASE 11 BLOCK.

11. SKELETAL MUSCLE
RELAXANTS
PERIPHERAL ACTING CENTRAL ACTING

12. NOTES ON INDIVIDUAL COMPOUNDS

13. PRIPHERALLY ACTING DRUGS
SUCCINYLCHOLINE
• MOST COMMONLY USED MUSCLE RELAXANT FOR PASSING TRACHEAL TUBE.
• IT INDUCES RAPID,COMPLETE AND PREDICTABLE PARALYSIS.
• SCh IS USED BY CONTINOUS i.v. INFUSION FOR PRODUCING CONTROLLED
MUSCLE RELAXATION FOR LONGER DURATION.
• SHOULD BE AVOIDED IN YOUNGER CHILDREN BECAUSE RISK OF
HYPERKALEMIA AND CARDIAC ARRYTHMIAS.

14. PANCURONIUM
• SYNTHETIC STERIODAL COMPOUND MORE POTENT AND LONGER
ACTING THAN d-TC.
• RAPID i.v. INFUSION CAUSES RISE IN BP AND TACHYCARDIA.
• ELIMINATION BY KIDNEY.
• USE RESTRICTED TO PROLONGED OPERATIONS ESSPECIALLY
NEUROSURGERY.

15. USES

16. PERIPHERALLY ACTING MUSCLE RELAXANTS
• ADJUVANTS TO GENERAL ANAESTHESIA.
• ASSISTED VENTILATION.
• CONVULSION AND TRAUMA FROM ELECTROCONVULSIVE THERAPY CAN BE
AVOIDED.
• SEVERE CASES OF TETANUS AND EPILEPTICUS.

17. CENTRALLY ACTING MUSCLE RELAXANTS
• ACUTE MUSCLE SPASMS.
• TORTICOLLIS,LUMBAGO,BACKACHE,NEURALGIAS.
• ANXIETY AND TENSION.
• SPASTIC NEURALGIC DISEASE.
• TETANUS.
• ELECTROCONVULSIVE THERAPY.
• ORTHOPEDIC MANIPULATIONS.