Parecetamol, Panadol, Tylenol, Captin, Dyamadon, Frenadol, y más...

[Andrés Amado Zuno Arce]

Normalmente se comercializa como suspensión líquida, en comprimidos o como supositorio. El Panadol, que se vende en Europa, America Latina, Asia y Australia, es la marca más extendida, vendida en más de 80 países. En Norteamérica, el paracetamol se vende como genérico o bajo varias marcas: por ejemplo Tylenol (McNeil - PPC, Inc), Anacin 3 y Datril.

En algunas formulaciones el paracetamol se combina con el opioide codeína, a veces llamado co-codamol, como por ejemplo el Algidol (Almirall) en España, lo que lo convierte en más tóxico, lo mismo que en todas las convinaciones. En los Estados Unidos y Canadá se vende como Tylenol 1/2/3/4; en los EE.UU. sólo se puede adquirir con receta médica, lo contrario que en Canadá. En el Reino Unido y en otros muchos países, esta combinación se vende como Tylex CD y Panadeine. Otras marcas disponibles son: Captin, Disprol, Dymadon, Fensum, Hedex, Mexalen, Nofedol, Pediapirin,atamel y Perfalgan. En España puede adquirirse indistintamente como genérico o como medicamento "de marca", como el muy conocido Efferalgan de (Upsa), Termalgin (Novartis), Gelocatil o Frenadol (compuesto con Dextrometorfano, ácido ascórbico y clorfelamina comercializado por McNeil).

También se puede combinar con oxicodona, por ejemplo el Percocet en EEUU.

La FDA estima que cerca de 400 Americanos mueren anualmente debido a la toxicidad de acetaminophen. Muchos más que las supuestas epidemias de influenza aviar y porcina, que han sido solamente brotes, por su cuantía.

Dear Andres Amado, The following articles and publications are now available online: Worst Pills, Best Pills Newsletter Articles Another Chapter in the Long History of Exposing the Dangers of the Most Popular Drug in America LA MÁS POPULAR DROGA EN EUA: This article documents how long it has taken the FDA to fully implement a reccomendation from its own advisory committee 32 years ago stating that: "Do not exceed the recommended dosage [acetaminophen--as in Tylenol] because severe liver damage may occur." Other countries have done more.  Este artículo documenta cuánto tiempo ha tomado a la FDA para llevar a cabo una total recomendación  de su propio comité consultivo que declaró eso hace 32 años: "No exceda la dosificación recomendada [el acetaminofenol--como en Tylenol] porque  lesión hepática severa puede ocurrir." (Pero la presentación "extra-strength" tablets of 500 milligram acetaminophen" tiene dosis, extra, sí,  dañinas) Otros países han hecho más. (Favor de informar a quienes toman eso, por su bien) El acetaminophen, el nombre impronunciable para el calmante de dolor más ampliamente usado en los Estados Unidos (TYLENOL), puede destruir al hígado en dosis ordinarias o  cerca de ordinarias. Ese hecho será una nueva para muchos consumidores pero algo sabido para los especialistas en hígado, y ahora se reconoció finalmente oficialmente en abril, 2009, por la Administración de Comida y Droga (FDA) de EUA. El que tomó a la  FDA 31 años para sacar esta conclusión habla sobre la manera "casual" de que tantos americanos tragan el calmante de dolor, y también sobre los agujeros en el sistema regulador para la seguridad de las drogas—sobre todo cuando involucra drogas encontradas en casi cada botiquín americano, ya que el acetaminofenol está en marcas populares como TYLENOL y más de 100  productos. ARTÍCULO COMPLETO, AL FINAL. MÁS: Muscle Damage from Interactions Between Statins and Other Commonly Prescribed Drugs The article lists 38 prescription drugs that can harmfully interact with statin drugs. The article also advises that No matter what statin you are taking and regardless of any interacting drugs, you should notify your prescriber immediately if you develop muscle pain, weakness or a darkening of your urine. . No More Free Drug Samples? The article discusses a variety of reasons why it is neither in the best interests of doctors to prescribe or patients to use free samples. The truism that "there is no such thing as a free lunch" rings true once again. Additional Information from Public Citizen Public Citizen's Response to FDA Draft Guidance on Conduct of Clincial Trials in Community-Acquired Bacterial Pneumonia (HRG Publication #1886) The Food and Drug Administration’s recent draft guidance on community-acquired bacterial pneumonia (CABP) is significant step forward from the previous draft guidance, issued in 1998. However, it includes recommendations that contradict established principles of rigorous clinical trial conduct, as defined in the International Conference on Harmonization documents E-9 and E-10, and a number of issues are left unaddressed. Testimony of Peter Lurie, M.D., M.P.H and Hillary Peabody, M.P.H before the FDA Transparency Task Force (HRG Publication #1883) Dr. Lurie and Hillary Peabody testify that pre-approval documents should be made available to the public, the FDA’s Freedom of Information Act (FOIA) processes should be made more efficient and consistent, and the FDA should expedite the production of standardized drug information for patients. Critique of New Antiarrhythmic Drug Dronedarone Published in the New England Journal of Medicine (HRG Publication #1878) James Floyd M.D. criticizes the new antiarrhythmic drug dronedarone. Testimony of James Floyd, M.D. at Meeting of Anti-Infective Drugs Advisory Committee on Cethromycin for the Treatment of Community-Acquired Bacterial Pneumonia (HRG Publication #1875) James Floyd, M.D. testifies about the design flaws in the studies conducted on cethromycin for the Treatment of community-acquired bacterial pneumonia. Letter Urging the FDA to Halt its Review of Prasugrel (HRG Publication #1876) Dr. Serebruany, Dr. Floyd and Dr. Wolfe encourage the FDA to stop its review of prasugrel until a new Phrase 3 study can be conducted with appropriate lower doses of prasugrel and properly defined outcomes. Go to Worstpills.org and log in to read these important drug updates. Don't forget to click on Recent Postings from any page on the site (except the home page) to check for updates more frequently, and remember - all of this information is now available in the Worstpills.org database simply by searching for the drug, disease, drug-induced disease, drug family, or policy issue discussed in each item. tell a friend | manage account | about | contact | join public citizen Public Citizen 1600 20th Street, NW Washington, DC 20009

Artículo completo sobre Tylenol:

Another Chapter in the Long History of Exposing the Dangers of the Most Popular Drug in America

     Worst Pills Best Pills Newsletter article July, 2009
    

The following article was written by Patrick Malone and Anne Larson. Patrick Malone is author of The Life You Save: Nine Steps to Finding the Best Medical Care — and Avoiding the Worst (published July 2009; Da Capo Lifelong 2009; www.lifeyousave.com). Anne Larson, M.D., is medical director of liver transplantation at University of Texas Southwestern Medical School, Dallas.

Acetaminophen, the unpronounceable name for the most widely used pain reliever in the United States (TYLENOL), can destroy the liver in ordinary or near-ordinary doses. That fact will be news to many consumers but is old hat to liver specialists, and now was finally acknowledged officially late in April 2009 by the Food and Drug Administration (FDA).

That it took the FDA 31 years to reach this conclusion speaks volumes about both the overly casual way that many Americans swallow pain relievers, and also about the holes in the regulatory system for drug safety — especially when it involves drugs found in nearly every American medicine cabinet, as acetaminophen is through popular brands like TYLENOL and more than 100 other products.

In 1977, an FDA advisory panel rocked the highly competitive world of over-the-counter (OTC) pain relievers when it proposed that acetaminophen, which had only become OTC a few years before, carry this warning on all packages: "Do not exceed the recommended dosage because severe liver damage may occur."

The makers of aspirin products, which carry their own risk of stomach bleeding but no risks to the liver, quickly trumpeted their own safety but in short order had to mute their horns when in the 1980s Reye’s Syndrome, a deadly disorder in children with viral diseases, was linked to aspirin consumption, and a whole generation of parents stopped giving their children baby aspirin and switched to what was then the only OTC alternative, acetaminophen.

The Johnson & Johnson subsidiary, McNeil, which makes TYLENOL, fought hard to persuade the FDA that "severe liver damage" was an unnecessarily alarming statement for the official product label because, it maintained, the only people who suffered such injury had taken massive overdoses, usually in suicide attempts. In 1988, the FDA issued a "tentative final monograph" agreeing with McNeil’s position, despite the accumulation of a series of case reports in the liver disease literature that "therapeutic misadventures" at or near recommended dosing levels caused acute liver failure. Most of the reports concerned alcohol drinkers who took three or more drinks a day and thus primed their livers to convert acetaminophen to a toxic byproduct through the same enzyme (cytochrome P450 2E1) that the liver uses to process large amounts of alcohol. In 1999, the FDA mandated an alcohol warning on acetaminophen labels.

As the regulatory gears ground slowly, liver transplant centers and intensive care units across the country treated a steady stream of acetaminophen victims: desperately ill patients every week who had succumbed to sudden liver failure. Their histories often involved generous dosing at or a little more than the recommended four grams a day (eight "extra-strength" tablets of 500 milligram acetaminophen). Often the patients did not realize they were exceeding the dosing limit because they were taking more than one pain reliever with acetaminophen. (For example, prescription pain relievers like acetaminophen and oxycodone [PERCOCET] and propoxyphene and acetaminophen [DARVOCET] contain acetaminophen, in addition to a narcotic, as indicated by the "-cet" in the name.) In less than half of these cases the patients were alcoholics.

A multi-center report led by investigators at UT-Southwestern documented that acetaminophen ingestion is the leading cause of acute liver failure in the United States. Acetaminophen ingestion accounted for 46 percent of cases, outstripping viral hepatitis and dwarfing liver failure due to all other drugs combined. The FDA estimates that around 400 Americans die annually due to acetaminophen toxicity.

The new package warning, which takes effect one year from now (a blink of an eye in the multi-decade history of this issue before the FDA), is very close to the original proposal from 1977. The packaging will state on 500-mg products:

Liver warning: This product contains acetaminophen. Severe liver damage may occur if you take more than eight tablets in 24 hours, the maximum daily amount.

It will also warn against using it with other acetaminophen products or with alcohol use of three or more drinks a day. The FDA rejected a request from the TYLENOL manufacturer McNeil to water down the warning by removing the word "severe" and adding the word "overdose," which the agency said could lead consumers to believe they had to greatly exceed the recommended dosage before jeopardizing their livers.

Two questions remain: Why did the FDA wait until 2009 to require what liver disease experts asked it to do in 1977? And what more needs to be done to protect the public?

The "final rule" published in April in the Federal Register makes it clear that many questions about who is at risk for acetaminophen poisoning remain unanswered. The FDA is calling for large safety studies, but it lacks any power to force manufacturers to fund them and has no budget for its own safety investigations. The studies that have been published over the years typically have featured a few score of patients whose cases are cobbled together on shoestring research budgets. An additional impediment to clear answers is that unlike most other advanced countries, the United States has only a voluntary system for adverse event reports for drugs and medical devices.

Other countries also restrict acetaminophen sales to discourage inadvertent overuse. The British Parliament passed legislation in 1998 limiting package size and mandating blister packaging which limits impulsive use and the likelihood of overdosing. These measures have been associated with a significant reduction in the number of intensive care admissions and liver transplantation for acetaminophen. The FDA may take up that issue at another hearing in June 2009. Items for consideration should include unbundling of the narcotic/acetaminophen compounds, since these have recently been associated with many unintentional overdoses and should certainly include discussion of limiting package size, since 500-tablet bottles and advertising that emphasizes its safety don’t fit with the overall picture of a potentially lethal drug.

--
         andreszuno.com

Lic. Andrés Amado Zuno Arce.
       

--
         andreszuno.com

Lic. Andrés Amado Zuno Arce.