Whether or not you have anxiety, you’ve probably heard of Xanax.
Somewhere north of 50 million Americans have a prescription for the drug, making it the
3rd most prescribed medication in the country.
That’s a lot of pills.
What’s in them?
How do they work?
This is your anxious brain, and this is your anxious brain on Xanax.
First let’s talk about what anxiety looks like in the brain.
Doctors are still working out the root causes of anxiety--the brain is a complicated thing.
What they’ve noticed though is that when people are feeling anxious or panicked, there’s
an uptick in activity in these parts of the brain responsible for processing emotions
and making decisions.
We don’t fully understand why that’s happening.
It may be that natural checks on overactivity are on the fritz.
But it helps explain why Xanax works.
Xanax--also called alprazolam--is part of a class of drugs called triazolobenzodiazepines.
Molecule names are like one of those German words that’s really a whole sentence smashed
together.
When scientists hear that crazy-sounding keysmash, they can actually tell how each syllable relates
to the molecule’s structure.
Since xanax’s structure is key to how it works, let’s take a quick dive in.
Triazolo refers to these three nitrogen atoms at the top.
Benzo is for benzene, the ring of carbon atoms on the left.
And diazepine is the ring between them with two nitrogens.
Xanax’s shape lets it interact with proteins on the outside of neurons in your brain.
These GABA-A receptors are gates that let chloride ions into your neurons.
Chloride ions are really important because they disrupt the balance of electrical charges
between the inside and outside of the neuron.
Charge is crucial since neurons use electrical impulses to send their signals.
Here’s what I mean.
Your neurons are like wires that send signals all through your body.
Where one neuron meets another, the messages are carried by molecules.
But inside the neuron, the signals are electric.
When the charge balance is disrupted, the signal’s get interrupted.
It’s a bit like a relay race.
The runner is an electrical signal moving down the axon.
At the end of her leg, she passes a molecular baton across the synapse.
But if you’ve taken a Xanax, the charge balance along the axon is out of whack wherever
there’s a GABA-A receptor.
Almost like someone dug a bunch of holes along the relay racer’s track.
That’s going to make it a lot harder for her to get the baton to the next neuron.
She might not be strong enough to hand the baton off at the end, she might not even make
it through her leg, or she might never leave the starting blocks to begin with.
The Xanax molecule is like a key that fits in the GABA-A lock.
The shape, structure and orientation of the rings helps Xanax fit snugly in GABA-A’s
binding pocket.
That triggers the flood of chloride ions into your neurons.
If there’s no signal to the next neuron, your brain quiets down.
There are biological molecules in your brain that do the same thing to GABA-A; Xanax is
just copying their work.
For whatever reason, those natural processes aren’t working in the right way in the anxious
brain.
So by activating their GABA-A receptors and quieting their neurons, Xanax is like hugging
your dog during a thunderstorm and telling her everything is going to be okay.
But for your brain.
Kind of nice, right?
On the flip side though, one of the side effects of Xanax is sleepiness or sluggishness.
The drug is basically stopping your brain from talking so much, and it starts to feel
like nap time.
Now, scientists don’t know exactly which neurons or parts of the brain cause anxiety.
Recent research points to some likely culprits.
What we do know is that Xanax is effective for helping people with acute anxiety live
a normal life.
Unfortunately, Xanax can lead to addiction, especially for people who are abusing it and
not taking it under doctor’s orders.
Overdoses are a problem too.
Xanax and other benzodiazepines are among the drugs that send people to the ER the most,
at least in the USA.
Some doctors worry that Xanax and other drugs in its class are being prescribed too often
or too casually.
That said, for the millions around the world who use it to treat panic attacks and other
anxiety issues, Xanax can be a lifesaver.
Have any other chemistry questions about how the body works?
Or want to know how other drugs do what they do?
Leave them in the comments and we might tackle them in a future episode.
Thanks for watching.