Category: Teaching

Health Care Series 20090611: Acetaminophen Concerns

THURSDAY NIGHT IS HEALTH CARE CHANGE NIGHT, a weekly Health Care Series (cross-posted at ePluribus Media. I have been invited to contribute this installment. I originally was going to post about high fructose corn sweetener, but between the time of the invitation and now FDA came out with a new warning about acetaminophen. Acetaminophen is one of the most widely used pain and fever relievers in the United States. Much of the widespread use has to do with the fact that it causes less stomach upset and GI bleeding than aspirin or ibuprofen. It is not linked to Reye Syndrome as is aspirin, making it a good choice for children and teens with flu. Another very large reason for widespread use is heavy marketing.

However, acetaminophen has a very dark side.  According to CDC, right at half of all cases of acute liver failure (ALF) in the United States is directly caused by acetaminophen.  I will not be as geeky in this post as I normally am in my regular Sunday evening series, Pique the Geek, where we try to delve fairly deeply into the science of various topics.  However, some scientific and historical background is necessary to understand the process of liver toxicity produced by this material.In 1887 a drug called phenacetin was first marketed for fever and pain. It is actually made from acetaminophen and is metabolized in the body to it.  It was withdrawn from the United States market in 1983 due to concerns over carcinogenicity.  However, acetaminophen had already replaced it in a large share of the market.  The reason that phenacetin was used for so long had to do with sloppy research in the early 20th century.

Acetaminophen was first introduced in 1953 by Winthrop, but in 1955 McNeil began marketing Tylenol Children’s Elixir, and the Tylenol brand is still probably the most widely recognized brand name in the United States.  Now it outsells aspirin, and I believe this is a dangerous situation.

All medications are eliminated from the body, mostly as metabolites of the parent drug.  The major site of metabolism is the great chemical factory of the body, the liver.  There are three major pathways, two of them harmless.  The first one is addition of glucuronic acid (a sugar derivative) in the liver, producing a metabolite that is nontoxic and is eliminated by the kidneys.  It is thought that, in MOST people, about 40% of the drug is eliminated that way.

A second pathway, also harmless, is addition of sulfate in the liver, forming a water soluble metabolite that is carried away by the liver.  In MOST people this accounts for around 20% to 40% of the total load.

The third pathway, accounting for about 15% of drug clearance, involves the cytochrome P450 set of liver enzymes (the ones that are increased by drinking alcohol).  A toxic intermediate called NAPQI is formed, and that is cleared by combination with the natural antioxidant glutathione and eliminated by the kidneys.  Here is where the problem arises.

NAPQI is highly reactive and combines with the lipids in liver cell membranes, killing the cells.  When combined with gluatathione, it becomes nontoxic, but glutathione is essential for liver protection from the thousands of other reactive oxidizing agents that it processes constantly.  Reduction of glutathione thus also damages the liver, since it is not available to protect the liver from other bad actors.

In most people, the recommended dose of acetaminophen does not cause any outward sign of trouble.  However, there are behaviors that increase sensitivity towards toxicity.  As mentioned before, moderate to heavy alcohol intake induces the very enzyme that is responsible for the “bad” pathway, so drinkers are naturally more susceptible.  Besides, alcohol in large doses is a liver toxin in its own right, so that is a double whammy.

Another risk factor is fasting and low protein diets.  Since glutathione is derived from protein, restriction of protein intake reduces its availability, thus decreasing its protective effect on the liver.

A third risk factor may be caffeine.  Some fairly recent work is consistent with the hypothesis that caffeine induces a liver enzyme that also causes the production NAPQI, presumably Cytochrome P450.  Now this is problematic for a couple of reasons.  First, many folks drink a lot of coffee.  Second, caffeine is often added to painkiller medications to increase their potency.  Some of these combinations include acetaminophen.

There are also other drugs that induce these enzymes, particularly anticonvulsants.  The barbiturates are potent inducers, and a few combination products contain a barbiturate, a narcotic, and acetaminophen.

In most normal people with no other risk factors, four grams of acetaminophen will show up on liver function tests after a few days for about a third of the population.  Well, four grams a day is the maximum recommended dose for Tylenol Extra Strength products according to the Tylenol website.  So, recommended doses affect liver function in one third of people with no other risk factors.  This is not good.

Six grams a day for two days can cause significant liver function disturbances in normal (that is, no other risk factor) individuals.  Now, I know a lot of folks who have the attitude, “if two tablets will help, three will help more.”  Here is how we start getting into trouble.

Thursday Medical Post

I thank the members here for asking me to post my science essays here as a primary site. I hope to make many new friends here. The next one has to do with acetaminophen, a very dangerous drug. If I am not welcome to post it here as my new primary site, please let me know. Warmest regards, Doc

Thursday Medical Post

I thank the members here for asking me to post my science essays here as a primary site.  I hope to make many new friends here.  The next one has to do with acetaminophen, a very dangerous drug.  If I am not welcome to post it here as my new primary site, please let me know.

I need help to make this diary series to make sense.  New here, I do not understand the conventions.  Help would be appreciated.

Warmest regards,

Doc

First Amendment Friday 7 – New York Times v Sullivan

Happy Friday and welcome to the 6th in the Dog’s First Amendment Friday series. This series is following the syllabus for the class called The First Amendment and taught at Yale Law School by Professor Jack M. Balkin. As with the Friday Constitutional series this is a layman’s look at the Law, specifically the Supreme Court opinions which have shaped the boundaries of our 1st Amendment Protections. If you are interested in the previous installments you can find them at the links below

Originally posted at Squarestate.net

First Amendment Friday 6 – Planned Parenthood V. ACLA

Happy Friday and welcome to the 6th in the Dog’s First Amendment Friday series. This series is following the syllabus for the class called The First Amendment and taught at Yale Law School by Professor Jack M. Balkin. As with the Friday Constitutional series this is a layman’s look at the Law, specifically the Supreme Court opinions which have shaped the boundaries of our 1st Amendment Protections. This week we don’t actually have a Supreme Court case, as the High Court refused to take up the appeal on this one. It is still part of Professor Balkin’s syllabus and as we look at the details you will see why it is an important First Amendment case. If you are interested in the previous installments of this series you can find them below:

In the beginning, god created…

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First Amendment Friday 5 – Bridges V California

Happy Friday and welcome to the 5th in the Dog’s First Amendment Friday series. This series is following the syllabus for the class called The First Amendment and taught at Yale Law School by Professor Jack M. Balkin. As with the Friday Constitutional series this is a layman’s look at the Law, specifically the Supreme Court opinions which have shaped the boundaries of our 1st Amendment Protections. This week we will look at two cases which deal with the Press’s right to report and comment on cases still before the Courts.

The cases were decided together in an opinion titled Bridges V California. If you are interested in the previous installments of this series you can find them at the links below:

Café Discovery: Context, 1964

I was a sophomore at Lake Oswego High School for the first half of 1964 and a junior at at the end of it.  

Like 1963, the music ranged from the Beatles at the beginning of the year…to the Beatles at the end of the year.  The meaningful music, as far as I was concerned, was in between.

I pulled the news from 1964 out of wiki, every fifth story or so.  I’ve added some content and some memories and followed a few threads forward.

I found it an interesting study.  I hope you do, too.

Europe’s First Police State

So I know you were just sitting around wondering, “What are the origins of the modern police state?,” and maybe, “Can an effort at genocide, if sustained long enough, actually work?,” or possibly, “What would happen if a bunch of religious zealots were in a position to exercise spiritual, temporal, political, and military authority over all they survey?”   Well, Pope Innocent III, the same guy who launched the Fourth Crusade, certainly asked himself these questions, and he sought to answer them through direct action.

So join me, if you will, in the Cave of the Moonbat, to get a glimpse of a nobly enlightened culture as it is extinguished by the hate-filled love of the Medieval Church.  We’ll also see the heretical Cathars subjected to travesties that only these people would not find barbaric…

Why 137?

I’ve decided that I want to write about physics for a while…

I’ll get started by explaining my username. Well, the r and the b aren’t very exciting (they’re my initials), but the 137 represents a story about one of the fundamental constants in the universe: the Fine Structure Constant. The story, though, has to do with the way people tend to think about science.

First Amendment Friday’s 4 – Brandenburg V Ohio – Right To Assemble

Happy Friday and welcome to the 4th in the Dog’s First Amendment Friday series. This series is following the syllabus for the class called The First Amendment and taught at Yale Law School by Professor Jack M. Balkin. As with the Friday Constitutional series this is a layman’s look at the Law, specifically the Supreme Court opinions which have shaped the boundaries of our 1st Amendment Protections. So far we have been working through cases that have had to do with seditious speech. If you are interested in the previous installments in this series you can find them at the following links:  

The Nika Riots

The truly beautiful thing about history is the way it informs on such a multitude of levels.  Depending on the way one reads things, the same story can be anything from a simple, cautionary tale, to an eerily-similar depiction of current events, to a cause for awe and celebration of human achievement, to an inspiration for future generations – and all manner of interpretations in between.  But, since the understanding of history is ultimately a personal thing, I’ll leave it to my fellow historiokossians to figure out how we as a community should look at the story of the Nika Riot.

Join me, if you will, in the Cave of the Moonbat, for a look a one of the most divisive times in the history of one of the world’s great civilizations.  Now, far be it from me, a lowly historiorantologist, to claim that we as a community might see a bit of ourselves in the story – but I do confess to a hope that (if we have indeed laid waste to a third of our metaphorical city in the recent flamewars) the minds and passions here are capable of raising from the ashes our own Hagia Sofia.

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