1
Q
What is the MOA of Thiopental?
A
- decrease the rate at which GABA dissociates from the receptor
- Increase duration of GABA activation
- Increases chloride conductance- hyperpolarizes the cell
- Decreases neuronal transmission
- Decreases sympathetic ganglia transmission- hypotension
- decrease postsynaptic membrane sensitivity to AcH- muscle relaxation
- Decrease RAS- sleep
2
Q
What are the pharmacokinetics of thiopental?
A
- 70% protein bound
- highly lipid soluble
- crosses BBB
- onset-fast
- rapid redistribution in 2-4 minutes
- E1/2t 11.6 hours (hangover effect)
- metabolized by CYP450 with some extrahepatic metabolism and renal excretion
- Induces CYP450 which increases metabolism of Dilantin, anticoagulants, Vitamin K, TCAs, steroids.
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3
Q
What are the side effects of thiopental?
A
- decreased CBF, ICP, & CMRO2
- isoelectric EEG
- decreased IOP
- decreased BP, cardiac depression
- respiratory depression
- HISTAMINE release
- decreased laryngeal cough reflexes
- Increased heme production- bad in porphyria
- N/V
- anaphylaxis with high mortality
4
Q
What are the contraindications to thiopental?
A
- porphyria
- asthma
- pregnancy
- watch in drugs metabolized by CYP450
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5
Q
What is the dose of thiopental?
A
3-5mg/kg IV
6
Q
What is the drug class/ chemical description of thiopental?
A
- barbiturate
- thiobarbiturate with sulfur at carbon #2
7
Q
A
