How safe is your painkiller?
People pop painkillers for headaches, body aches, fever and arthritis, but even the safest medicine can become toxic if misused.india Updated: May 14, 2006 02:17 IST
People pop painkillers for headaches, body aches, fever and arthritis, but even the safest medicine can become toxic if misused. Perhaps the best example is that of the ubiquitous aspirin (acetylsalicylic acid). Few people know that children under 16 years should not be given aspirin because of its links with Reye’s syndrome, a rare but potentially fatal disorder in children that can harm the brain and liver.
That’s not all the harm packed in this little pill, which is often hailed as one of the biggest gifts to modern medicine. Aspirin can trigger a life-threatening reaction in one in five asthmatics. It may also cause brain haemorrhage in people who take it over a long period of time.
So, what should be the first line of treatment for pain?
All painkillers provide pain relief by blocking the action of cyclo-oxygenase (COX), an enzyme that helps in the production of a chemical called prostaglandin. One of prostaglandin’s many actions is to trigger signs of inflammation such as pain, swelling and redness in response to injury or certain diseases.
“Paracetamol is the safest for those under 16 years, while aspirin, paracetamol and ibuprofen are the best choices for those over 16 years,” says drug expert Dr CM Gulati, editor, Monthly Index of Medical Specialities. Though paracetamol does not possess the anti-inflammatory properties other pain relievers have, it is widely accepted because it’s safe for all age groups and pregnant and lactating women, and at the recommended dosage (over 150 mg of paracetamol per kg body weight for children, and over 12 gm or 24 500-mg tablets for adults), there are virtually no side effects. It’s also recommended for people who are allergic to aspirin and for those with peptic ulcers because it rarely produces stomach irritation and does not interfere with blood clotting.
But paracetamol has its limitations. Because it lacks anti-inflammatory properties, it is not as effective as non-steroidal anti-inflammatory drugs (NSAIDs) for long-term pain-relief needed for conditions such as rheumatoid arthritis and osteoarthritis.
Aspirin, on the other hand, is a COX inhibitor that is excellent for adults as it also lowers risk of heart attack and stroke. Unlike paracetamol, aspirin has anti-inflammatory properties and reduces fever, redness and swelling. The most common side effect of aspirin is irritation of the tissue that lines the stomach, which can lead to an upset stomach or bleeding in people with a history of peptic ulcers or gastrointestinal tract disorders.
“Lactating women, people going for surgery and those prescribed other anti-coagulants (blood thinners) should not have aspirin,” says Dr Anoop Misra, senior consultant in internal medicine at Fortis Hospitals.
Last come prescription NSAIDs that block COX enzymes — COX1 and COX 2 — selectively to lower inflammation, pain, and fever. The most commonly prescribed NSAIDS are diclofenac, ibuprofen and naproxen, which bring down inflammation as well as pain. “Ibuprofen and diclofenac is the best and safest options for long-term use when taken on prescription,” says Misra.
COX-2 selective NSAIDS have been associated with increased heart and stroke risk, leading US Food and Drug Administration asking manufacturers to revise the labelling (package insert) to include a boxed warning highlighting increased risk of heart attack and stroke and potential life-threatening gastrointestinal bleeding.
While valdecoxib and rofecoxib have been voluntarily withdrawn from the US market by the manufacturers, mandatory celecoxib labelling is required to contain safety data from long-term treatment trials with celecoxib.
Staying alert for the first signs of toxicity helps. Expert say you should discontinue use of the medication and consult a doctor at once if you spot allergic reactions such as rashes, wheezing, swelling of the face and mouth, or side effects such as ringing in the ears or hearing loss, stomach irritation, blood-stained or black stools.