Thursday, July 31, 2008

Acetaminophen: Over the Counter Danger?

As an analgesic that can be bought over the counter with ease – even without prescription, does the general public know the inherent dangers posed by acetaminophen / paracetamol medication?

By: Vanessa Uy

Despite the medication’s widespread use, most of the general public remain oblivious when it comes to the inherent health risk posed by apparently harmless over the counter analgesics like acetaminophen - also known as paracetamol. Even though most of these analgesics have warnings clearly posted on their box that these medications can cause liver failure in high doses, incidences of acetaminophen overdoses still occur.

Persons taking high doses of acetaminophen – especially those not overseen by a qualified physician – often run the risk of liver damage and / or impaired liver function. The liver can be overwhelmed in metabolizing high doses of acetaminophen / paracetamol. Young children are especially at risk. The established recommended dose of acetaminophen is around 50 milligrams per kilogram of body weight per day. While the upper limit maximum dosage – usually administered in special cases – is 3 to 4 grams (3,000 to 4,000 milligrams) per day even though this amount can be harmful to a statistically significant portion of the population. Susceptibility to liver damage by high doses of acetaminophen is not just limited to overweight persons – as previous studies suggest – but also on healthy individuals as well. Even though precautions about taking paracetamol / acetaminophen is clearly posted in the medication’s packaging, why then there are still incidences of individuals overdosing on this specific drug?

The still common incidence of overdosing on acetaminophen is largely blamed on medical professionals prescribing the drug for pain in which the drug has shown only marginal effectiveness like pre and post operative dental work – i.e. toothache. Given acetaminophen’s somewhat marginal effectiveness in relieving such maladies the patient often resort to taking the drug in doses far beyond their doctor or dentist’s recommended dose just to relieve existing pain.

Even though acetaminophen is primarily utilized to decrease fever by a hypothalamic effect leading to sweating and vasodilation the drug can also cause analgesia (pain relief) by inhibiting Central Nervous System prostaglandin synthesis; however, due to minimal effects on peripheral prostaglandin synthesis, acetaminophen has no anti-inflammatory or uricosuric effects. Unlike aspirin, which this particular drug was designed to replace, acetaminophen does not cause any anticoagulant effect or ulceration of the gastrointestinal tract. But compared to nonsteroidal anti-inflammatory drugs like Bextra and Vioxx which has gained widespread press notoriety due to it’s unforeseen side-effects, acetaminophen / paracetamol is still magnitudes safer compared to those drugs. Yet a degree of prudence still needs to be exercised in taking supposedly safe medication because the old adage still holds true today that the difference between a medicine and a poison is in the dosage.

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