skeletal muscle relaxant vs. thiopental

1. Drug Incompatibility
skeletal muscle relaxant vs.
thiopental
BY LAITH J. ABDULREDHA

2. Skeletal muscle relaxant :
 Muscle relaxants are medicines that
block cholinergic transmission of
nerve impulses to the muscles.
( motor nerve ending and NM end
plate of skeletal muscle )
 They sometimes are also referred to
as neuromuscular blocking
agents.

3. What are they used for?
 Facilitate intubation of
the trachea
 Optimized surgical
working conditions

4. Skeletal muscle relaxant :
 Atracurium
 Cistracurium
 Pancuronium
 Vecuronium
 Rocuronium
 Mivacurium

5. Thiopental sodium
 Barbiturate used for induction of
anesthesia
 Administered by slow intravenous
injection or continous IV infusion

6. Incompatibility
 There is a chemical incompatibles
between muscle relaxant and
thiopental
 Muscle relaxants are Incompatible
with high pH solutions, must be
administered separately to drugs with
high pH such as thiopental to prevent
precipitation

7.  The issue of precipitation becomes very
important in rapid sequence inductions of
anesthesia when a muscle relaxant is
injected immediately after thiopental.
 Precipitation is more likely to occur
when the IV fluid does not flow freely
and with use of small-bore
angiocatheters (22-gauge or smaller)

8. pH of thiopental and SMR
Drug pH
thiopental 11-12
mivacurium 4 -5
vecuronium 4
Rocuronium
m
4
atracurium 3.5

10. Solution of problem :
 a combination of a free-flowing drip
as well as fluids running through it
can minimize potential difficulties
 When no fluids are being
administered, then a generous saline
flush clear cannula and vessel
 alter the drugs used

11.  Precipitation of Thiopental by Some
Muscle Relaxants/ Chambi, Denis MD;
Omoigui, Sota MD Anesthesia & Analgesia:
November 1995 - Volume 81 - Issue 5 - p 1112
 Mixing medicines: how to ensure
patient safety /The Pharmaceutical
Journal14 APR 2015By John Bentley, Katie
Heard, George Collins, Chris Chung