how travel sickness medication works (e.g. Kwells)?



how travel sickness medication works (e.g. Kwells)?

In: Chemistry

Believe it or not, your brain has an area that tells you to throw up. Unsurprisingly, it’s called the “vomit center” of the brain and is located in the medulla obongata. There are multiple pathways to activate the vomit center, but since you asked about motion sickness we will talk about that one. Basically, your inner ear plays a big role in how you balance and orient yourself. When you have motion sickness, it can be because there is a disconnect between what your inner ear feels and what your eyes see. When this happens, your body panics and says “oh no, I’ve been poisoned!” and sends a signal to your vomit center, which in turn makes you nauseous and puke. Of course you haven’t been poisoned, but your body can be stupid sometimes and can’t differentiate between certain stimuli and just assumes that if two of your systems don’t agree that there is something in your body that shouldn’t be. Ergo, the vomit.

So how do the medications work? Basically, the inner ear and the brain don’t “talk” directly to each other; the inner ear sends a messenger to the brain to tell it what’s going on. This messenger’s name is acetylcholine. Acetylcholine travels up to the vomiting center, says “stuff is all messed up yo,” the brain says “no problem, I got you” and then you barf. Medications like Kwells (which is hyoscine or scopolamine) are called anticholinergics, as in anti-acetylcholine (technically they’re antimuscarinics, but that’s not important). Acetylcholine takes a message from the inner ear and tries to go to the brain, but the anticholinergic medication says “sorry bro, can’t let you talk to the brain.” The message doesn’t get delivered and you don’t end up praying to the porcelain gods.