Sketchy Pharm: Barbiturates

Question 1

Although both the benzodiazepines and barbiturates activate the GABA(A) channel, they have different effects. Explain!

Answer 1

Benzodiazepines cause GABA(A) to open more frequently (just like how the pamcakes cause Ben’s diner to open more frequently), while barbiturates cause it to stay open longer (like how you get LONG hair cut at the BARBershop).

Question 2

There is a barbiturate that takes effect quickly and has its effect wear off quickly. What is it and why does this occur?

Answer 2

Thiopentol (THe Ol’ quick shave); it goes straight to the brain and then redistributes to adipose tissue – used for intubation, given IV.

Question 3

Why is phenobarbital not first-line for seizure treatment?

Answer 3

It has some bad side effects: hypoventilation, cardiac depression, CNS depression to the point of coma, and an extremely long half-life (think of the long, tapering barber flag).

Question 4

A low dose of _________, along with propranolol, can treat essential tremor.

Answer 4

primidone (Perm is Done!)

Question 5

Phenobarbital and other barbiturates are potent ________ of the CYP450 system.

Answer 5

inducers (the kid getting cranked up with his CYP450 chrome bumper) – so they increase the metabolism of warfarin and other hepatically metabolized drugs –