Highlighting pharmacokinetics, pharmacodynamics and mechanism of action


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US brand name: BuSpar
Generic name: buspirone


BuSpar’s Half-Life & How Long Until It Clears Your System

Half-life: 2 to 3 hours. Clearance: one day, three days at the most.

Steady State

Half-life is the average time it takes for you to process half of the drug’s active ingredient. If a drug has a half-life of around 24 hours and you take a dose of 100mg, you’ll have roughly the equivalent a 50mg dose after one day, a 25mg dose after two days, and so on. The rule of thumb is: multiply the half-life by five and you get how long it is for the dose you took to be cleared from your bloodstream1.

Steady state is the flipside of half-life. This is when you can expect to get over side effects caused by fluctuating amounts of a medication in your bloodstream. Often, but not always the same amount of time as the plasma clearance above.

How buspirone Works

the current best guess at any rate
[:moa: As with most of these crazy meds it’s easier to say what BuSpar doesn’t do. BuSpar doesn’t do any of the fun benzodiazepene fuck-you-up-and-get-high effects. BuSpar doesn’t knock you out. BuSpar doesn’t hit GABA.

What BuSpar does do is to keep serotonin within the 5HT1A neurons, thus fooling your brain into thinking it has more serotonin than it actually has. BuSpar also does some noticeable dopamine agonism-antagonism on the dopamine D2 receptor. When combined with an SSRI this can help with sexual dysfunction and to prevent SSRI poop-out, per Dr. Stahl in Essential Psychopharmacology. :]

Active Ingredient

buspirone hydrochloride

The active ingredient is usually the same as the generic name, but more often than not it’s a chemical salt of the substance identified as the generic. E.g. Fluoxetine is the generic for Prozac, but the active ingredient is fluoxetine hydrochloride (or HCl). It usually doesn’t make much of a difference outside of the more esoteric aspects of a drug’s pharmacology, but not always.

Shelf Life

3 years

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Pages and Forum Topics Google Thinks are Relevant to Your Mental Health

1 After five times the half-life you'll have reached what's called "Plasma clearance," or "not enough left in your bloodstream to latch onto your brain and do anything." It's based on Julien's calculations from A Primer of Drug Action, and half-life multiplied by five is the generally accepted estimate of how long it takes a single dose of any given drug to be eliminated from the blood stream/plasma of someone with a normal metabolism. That's also the rough estimate for steady state if they can't get, or won't provide a number for that.
The next level is "Complete clearance", and is a complex equation based on a lot of factors which may or may not: be published in the PI sheet, include personal data like your weight, or even completely figured out by corporate and independent researchers. It usually winds up being within (as in usually, but not always, after) 2-5 days of plasma clearance no matter what, but sometimes can take weeks. Sometimes a drug will clear from your brain and other organs before it clears from your blood.
That's how it works for crazy meds. I have no idea what the average complete clearance is for other types of medications. For all I know there are drugs that utterly vanish from your system in under five passes, and others that won't let go of your squishy bits for years after you stop taking them.

Last modified on Wed, 04 May, 2016 at 16:43:39 by JerodPoorePage Authors Date created Friday, 8 July 2011 at 10:56:00
“BuSpar (buspirone) Pharmacology” by JessicaAllan is copyright © 2011 JessicaAllanPublished online 2011/07/08

BuSpar, and all other drug names on this page and used throughout the site, are the trademarks of someone else. BuSpar’s PI Sheet will probably have the name of the manufacturer and trademark owner (they’re not always the same company) at or near the very bottom. Or ask Google who the owner is. The way pharmaceutical companies buy each other and swap products like Monopoly™ real estate, the ownership of the trademark may have changed without my noticing. It may of changed hands by the time you finished reading this article.

Page design and explanatory material by Jerod Poore, copyright © 2003 - 2016. All rights reserved. See the full copyright notice for full copyright details.
Don’t automatically believe everything you read on teh Intergoogles. No warranty is expressed or implied in this information. Consult one or more doctors and/or pharmacists before taking, or changing how you take any neurological and/or psychiatric medication. Your mileage may vary. What happened to us won’t necessarily happen to you. For more details see the Crazymeds big-ass disclaimer.

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