cocaine problem

[dr barb]

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I missed the lecture in pharmacology where he discussed the relative absorption of cocaine in its free base and HCL forms and he did not cover the material well in the notes. Can anybody explain to me which form is absorbed better? My guess is that since the HCL form is charged, that it will not penetrate membranes very well and therefore the preferred form to take if someone wanted to get high would be the free base form (hence the term - 'free basing'). Can anyone out there elucidate the details for me?

 

[A.D.O.R.]

seeing as how ritalin (d/l-methylphenidate HCl) is sold in its hydrochloride form and due to its mechanistic similarity to cocaine, I can only assume that HCl is needed for absorption. Otherwise why would money-conscious drug companies waste money on this extra step? Anyway, I'm curious about the correct answer to this question.

 

[Zweihander]

I used to work with the stuff; my understanding is that the free base doesn't dissolve as easily, whereas the HCl (what I used) dissolves VERY easily (in water).

Also, cocaine should never have to penetrate membranes -- as it is a dopamine reuptake inhibitor, it's work is done outside of the cell (unlike, say, amphetamine) by blocking the DAT.

Hope that helps.

 

[A.D.O.R.]

what did you use to do with the stuff (cocaine)?

 

[Zweihander]

Originally posted by A.D.O.R.
what did you use to do with the stuff (cocaine)?

I made some lucky rats very, very happy.😀


I was actually doing research for a while on drug-driven synaptic plasticity, studying mechanisms of action and (when appropriate) potential mechanisms of addiction.

Lots of neurochemistry. Fun stuff.


-Z

 

[ckent]

Originally posted by Zweihander
I used to work with the stuff; my understanding is that the free base doesn't dissolve as easily, whereas the HCl (what I used) dissolves VERY easily (in water).

Also, cocaine should never have to penetrate membranes -- as it is a dopamine reuptake inhibitor, it's work is done outside of the cell (unlike, say, amphetamine) by blocking the DAT.

Hope that helps.

Yes, that's true. Cocaine hcl is used for IV drug abuse, whereas the free base form must be smoked. Among other things, cocaine inhibits NE and Epi reuptake.

 

[A.D.O.R.]

are crack and free-base cocaine synonymous? also, does cocaine cost more because of the extra preparation step? i'm not considering a career as a street-corner pharmacist but i've always been curious about these things.

 

[....]

"are crack and free-base cocaine synonymous? also, does cocaine cost more because of the extra preparation step?"

Yes they are. If your black the news says your on crack. If you a white you are "freebasing", much more elegant. Oh well thats the media.

I actually think i costs less. A gram of coke is about 40 bucks, a vial of crack is 10 i think, but i dont know how much is in that. I know crack gives you more bang for your buck. The "serving size of each is a unit of the above prices.

I wonder why your lungs prefer the non polar form, but your nasal epithilium prefers the HCL salt......guess ill learn in med school.

 

[Adcadet]

a few things....

as to why the nasal epithelium "prefers" the salt (HCl) and the lungs prefer the free base - I don't think this is really true. I would guess that the salt (HCl) simply can't easily be smoked. I'm sure you can snort the base, but that wouldn't be as good (pharmacokinetically) as smoking it.

As to the claim that the charge on cocaine makes no difference as it does not have to cross a membrane to work: while the mechanism may not require crossing a membrane, it's pharmacokinetic parameters are highly influenced by the charge. But regardless of the mechanism of preparation, I would assume that cocaine will have whatever charge it wants as soon as it hits the bloodstream.

My impression (from being in a pharmacokinetic lab that used to, and still does cocaine) is that crack is all about maximizing absorption.

 

[doc05]

remember that the free base form (crack) can be smoked, which means it is easily absorbed via the lungs. the powered form is unstable at high temperatures and must be snorted.

 

[UnderDoc]

Crack and freebase cocaine are both the free base form of the drug but they differ in terms of their preparation. Apparently, crack cocaine is prepared via the addition of baking soda to a coke HCl solution whereas freebase preparation involves the use of NH4+ followed by ether extraction to yield a more pure product.

I found this info at this site ... gotta love the Internet...

 

[dr barb]

thanks for info everyone. leave it to med students to have such an extensive knowledge of crack and cocaine😀

 

[Goofyone]

THERE HAVE BEEN REPORTS of problems at some US medical schools. So, Dr.Goofy, on a quest for truth, interviewed several medical students across the country, via the student doctor forums. This is some of the disturbing comments he heard when asking students about reported school problems.

Dr. Goofy: "As a medical resident, what can you tell me about cocaine?"
Reply: "I used to work with the stuff"

Dr. Goofy: "So why, in your opinion, is science losing credibility?"
Reply: "I made some lucky rats very, very happy."

Dr. Goofy: "So are you saying you use cocaine?"
Reply: "Yes, I smoke it."

Dr. Goofy: "So why not inject it?"
Reply: "Remember that the free base form (crack) can be smoked, which means it is easily absorbed via the lungs."

Dr. Goofy: "As a black medical student, do you feel that the media, myself excluded, is putting too much pressure on you for your habit?"
Reply: "Yes they are. If your black the news says your on crack. If you a white you are "freebasing", much more elegant. Oh well thats the media."

Dr. Goofy: "Don't you think you're being irresponsible spending more money on cocaine than on your medical education?"
Reply: "I actually think i costs less. A gram of coke is about 40 bucks, a vial of crack is 10 i think, but i dont know how much is in that. I know crack gives you more bang for your buck. The "serving size of each is a unit of the above prices.

Dr. Goofy: "So, what have you learned from all of this?"
Reply: "My impression (from being in a pharmacokinetic lab that used to, and still does cocaine) is that, 'If you can't learn to do something well, learn to enjoy doing it poorly.'


This is Dr. Goofy, signing off. Just to prove my point, this was PROOF that medical schools are getting LESS COMPETITIVE!!!!


My apologies for butchering comments and quoting out of context at the expense of a good laugh, it was worth it.

 

[Zweihander]

 

[ramsestiger]

Hey, I was just studying similar info for my biochem test on Monday. Basically , you have to know the structure of the molecule to know the correct answer. Phenobarbitol is unionized and therefore more potent in its acidic form.

The ionization of the drugs is extremely important, because if the drugs are much more potent (larger % of unionized form) than "prescribed," then the body starts to use the bicarbonate system to buffer and compensate for the drug. As the bicarbonate system is disturbed, the blood's pH starts to lower or raise (can be seen clearly with the Henderson-Hasselbalch equation). The body starts to hyperventilate if the drug is more potent in its acidic form to raise the blood conc of CO2 to restore the HCO3- to CO2 ratio of 20/1. The person can go into a coma and even die if the blood pH isn't restored quickly enough. In this situation, the doctor must quickly administer HCO3- to the patient or the patient could DIE!

That's why it's extremely helpful to the medical staff if they know exactly which drug or toxin the patient took before passing out. Hope that helps.