Question 1

How do you remember Dantrolene?

Accepted Answer

Dantrolene breaks down as DANT = damp + ROLENE = ryanodine. Break dantrolene into DANT (sounds like damp) and ROLENE (sounds like ryanodine). Dantrolene damps ryanodine receptors, so calcium stays locked away, and the muscle stops moving. Next time you think of ryanodine, think of damp - ryanodine instead.

Question 2

What class of drug is Dantrolene?

Accepted Answer

Dantrolene is a Ryanodine Receptor Blocker • Malignant Hyperthermia • Direct Muscle Relaxant.

Question 3

How is Dantrolene tested on the USMLE?

Accepted Answer

Dantrolene blocks the ryanodine receptor on the sarcoplasmic reticulum, preventing calcium release into the cytosol. Without that calcium, the muscle cannot sustain contraction, which is why it is the antidote for malignant hyperthermia triggered by succinylcholine or volatile anesthetics.

Question 4

Dantrolene and baclofen both reduce muscle contraction but act at entirely different sites. Where does dantrolene act, and why does that site make it effective in malignant hyperthermia?

Accepted Answer

A - Malignant hyperthermia is driven by a defective ryanodine receptor dumping calcium out of the sarcoplasmic reticulum, so the fix has to happen inside the muscle cell. Dantrolene damps that receptor directly, stopping the calcium release at its source.

Dantrolene

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