This document discusses neuromuscular blocking drugs, specifically curare alkaloids. It begins by introducing neuromuscular blockers and their uses in anesthesia and for muscle spasms. It then describes the two types - peripherally and centrally acting, listing examples of each. The main focus is on curare alkaloids, covering their types, mechanism of action by competitively blocking acetylcholine receptors, chemistry as isoquinoline or indole alkaloids, uses historically and in modern medicine, and some associated clinical features and disorders related to hypomagnesemia.

1. Neuromuscular blocking drugs
Presented by : Komal jain.
Pharmaceutical(chemistry)
Curare alkaloid

2. Contents
 Introduction
 Types of neuromuscular blockers
 Curare alkaloids
 Types of curare alkaloids
 Mechanism of action
 Chemistry of curare
 Uses of curare
 Clinical features and associated disorders.

3. Introduction
 The neuromuscular blocking agents
are used primarily in conjunction
with general anaesthetic to provide
muscle relaxation for surgery ,while
centrally acting muscle relaxants
are used mainly for painful muscle
spasms and spastic neurological
conditions.

4. Types of Neuromuscular blockers
Neuromuscular blocking agents are of two types
1.Peripherally acting:
A. Non depolarizing agents
i. Long acting : d-Tubocurarine , Pancuronium ,
Pipecuronium , Doxacurium
ii. Intermediate acting : Vecuronium , Atracurium
, Rapacuronium
iii. Short acting : Mivacurium
B. Direct acting : Dantrolene sodium , Quinine

5. 2 . Centrally acting :
• Metaxalone , Diazepam , Baclofen ,
• Tizanidine , Chlorzoxazone.

6. Mechanism of action
• . Curare is a nondepolarizing and
competitive inhibitor of
acetylcholine (ACh) at
neuromuscular junctions preventing
the binding of ACh to their
Nicotinic ACh Receptor .
• These postsynaptic nicotinic
receptors are responsible for
generating action potentials
resulting in muscle contraction .
• Thus, binding of the curare
prevents action potentials from
occurring at the postsynaptic
membrane and as a result, leads to
paralysis of voluntary muscle group
.

7. Chemistry of Curare
• The active ingredient in crude
curare is D-tubocurarine.
• Curare is an organic compound
classified as either an
isoquinoline or indole alkaloid.
In other words, they are
aromatic, nitrogen-containing
structures.
• Does not cross blood-brain-
barrier (BBB) due to two
quaternary nitrogens = polar
molecule
D-tubocurarine

8. Uses of curare
o Increased urination, reduce fever, promote
menstruation, reduce fever, and relaxation of
skeletal muscle.
o Antibacterial, anti-inflammatory, and antiseptic.
o When used for abdominal pain and treatment of
worms/parasites.
o Used as a muscle relaxant in electric shock therapy
to prevent traumatic complication.
o Curare was used in conjunction with general
anaesthetics.

9. Clinical features and associated disorders

Hypomagnesemia may be asymptomatic, yet when it is
symptomatic, the neurological manifestations include agitation,
tremor, myoclonus, seizures (rarely), confusion , coma, muscle
fasciculations, weakness, the presence of Chvostek's and
Trousseau's signs, tetany, and hyper‐reflexia.
 When the clinical manifestations of Mg deficiency are
determined by induction of deficiency in human , GI features
(anorexia, nausea, and vomiting), CNS features (weakness and
personality change), PNS features (positive Trousseau's and
Chvostek's signs) , tremor, and muscle fasciculations may be
observed.