Mehlman pharm cyclobenz/benz/diphenhydr/dantrolene Flashcards
Cyclobenzaprine. mechanism?
Structurally similar to TCAs; helps modulate pain sensation at brain stem.
Cyclobenzaprine. indication?
Muscle relaxant used for spasms
Structurally similar to TCAs; helps modulate pain sensation at brain stem?
Cyclobenzaprine
Benztropine. mechanism?
Muscarinic (cholinergic) receptor antagonist.
Muscarinic (cholinergic) receptor antagonist?
Benztropine.
Used to treat acute dystonia due to anti-psychotics?
Benztropine.
Benztropine. indication?
Used to treat acute dystonia due to anti-psychotics.
what is dystonia?
Dystonia is a brain condition that causes uncontrollable muscle movements.
Q:If patient starts antpsychotic and then gets stiff neck, oculogyric crisis (abnormal eye movements), or muscle rigidity WITHOUT fever, the answer = Tx?
benztropine
Diphenhydramine /
Chlorpheniramine. group?
First-generation histamine-1 (H1) antagonists.
First-generation histamine-1 (H1) antagonists.?
Diphenhydramine /
Chlorpheniramine.
Diphenhydramine /
Chlorpheniramine.
Diphenhydramine is quite possibly the highest-yield drug on USMLE.
.
Diphenhydramine /
Chlorpheniramine.
used when?2
acute dystonia, similar to benztropine, as well as motion sickness
Diphenhydramine /
Chlorpheniramine.
what side effects?
nasty anti-cholinergic
(anti-muscarinic) side-effects.
acute dystonia, similar to benztropine, as well as motion sickness?
Diphenhydramine /
Chlorpheniramine.
Diphenhydramine /
Chlorpheniramine.
anticholinergic side effects are good when we want to treat what?
acute dystonia
Diphenhydramine /
Chlorpheniramine.
Psych Qs will either list benztropine or diphenhydramine (or chlorpheniramine) as the answer, but not both at the same
time.
.
Diphenhydramine /
Chlorpheniramine.
For whatever reason, anti-cholinergic effects treat motion sickness.
what very specific drug used for motion sickness?
Scopolamine
is an anti-cholinergic used to treat motion sickness classically.
Diphenhydramine /
Chlorpheniramine.
I’ve seen NBME ask diphenhydramine straight-up for this (motion sickness) as well – i.e., the nasty anti-cholinergic side-effects are, once again, a good thing if the aim is Tx of motion sickness.
.
Diphenhydramine /
Chlorpheniramine.
1st-gen H1 blockers can cause what dysfunction and what other symptom?
1st-gen H1 blockers can cause cognitive dysfunction (delirium, as well as worsening of dementia) and drowsiness
Diphenhydramine /
Chlorpheniramine.
in what patients to avoid and why?
avoid in elderly and
locomotive/machine operators if at all possible.
cause cognitive dysfunction (delirium, as well as worsening of dementia) and drowsiness
Diphenhydramine /
Chlorpheniramine.
1st-gen H1 blockers can also ……?
cause anti-a1 adrenergic effects (orthostatic
hypotension)
Dantrolene. mechanism?
block ryanodine Ca2+ channel.
block ryanodine Ca2+ channel?
Dantrolene.
Dantrolene. Tx for what?2
for neuroleptic malignant syndrome (NMS) and malignant hyperthermia (MH).
Dantrolene.
NBME will sometimes give vignette of NMS or MH, and then the answer for Tx is mentioned mechanism of drug.
Blocks ryanodine Ca2+ channel/decreases sarcoplasmic calcium release.
If patient gets muscle rigidity and fever following commencement of antipsychotic, or following administration of succinylcholine during surgery, Tx?
Dantrolene.
In NMS and MH, the ryanodine channel, which allows calcium to move from the sarcoplasmic reticulum into the cytosol, gets stuck open, so high amounts of calcium moves into the cytoplasm. The cell then needs to use a lot of ATP to pump the calcium back into the sarcoplasmic reticulum. This generates heat -> fever.
Dantrolene closes this channel.
.
