Barbiturates Flashcards
1
Q
Method of Action
A
Bind GABAa at allosteric site different to that of benzos and others (increase duration of opening)
Longer T1/2 than benzos with more hangover (not thiopental)
2
Q
Thiopental
A
Ultra-short acting
Used for induction in rapid sequence intubation
Administered I.V.
30 seconds for effect
Lipid soluble and immediately enters CNS
5-10min duration due to redistribution into fat and skeletal muscle
3
Q
Phenobarbital
A
Treat generalised and focal seizures Administration is slow Causes prolonged sedation High risk of hypoventilation and hypotension T1/2: 75-100 hours
4
Q
Primidone
A
Phenobarbital is an active metabolite
Used to manage seizures
Used with propanolol to treat essential tremor
5
Q
Side Effects
A
Hypotension Respiratory depression Coma Always avoided in the elderly Exacerbated by other CNS depressants Tolerance and physical dependence Addiction
6
Q
Pharmacokinetics
A
Metabolised by CYP450
Inducer of this system- increase metabolism of Warfarin and Statins