10/17/2011 12:35 EDT | Updated 12/17/2011 05:12 EST

Confused by the wall of pain relief meds? Choosing by need, not price a good idea

TORONTO - Go into any pharmacy looking for something to cure a headache or get rid of a backache and the options are overwhelming. How do you choose when you are standing in front of the wall of pain relief?

Do you want acetaminophen or naproxen? Aspirin or Aleve? Gel caps or standard pills? In 24-, 48- or 100-pill packs? It's easy to see why some people grab what's on sale, or gravitate to the brand they've always used.

For healthy people, that approach to selecting an analgesic is probably fine, experts say. But for some people, or in some circumstances, pain medication — even the over-the-counter kind — ought to be selected with more care, they advise.

For starters, pharmacologist Dr. Muhammad Mamdani thinks we as a society ought to think first about whether we need an analgesic before reaching for one. We take too many of these drugs, in his opinion.

Too many is a judgment call, but there is no doubt we take a lot of them.

IMS Brogan, a division of health information provider IMS, tracks drug sales in Canada. It says manufacturers and wholesalers sold $190.8 million worth of non-prescription analgesics to Canadian hospitals and pharmacies in 2010. The runaway favourite was Extra Strength Tylenol, with sales of over $43.7 million.

Mamdani says non-drug options like massage therapy, exercise, or ice or heating packs can help with pain.

"Pain is highly subjective and ... in many cases can be managed without drugs," says Mamdani, who is director of the Applied Health Research Centre in the Li Ka Shing Knowledge Institute at Toronto's St. Michael's Hospital.

But if you are going to take an analgesic, his advice to healthy people is simple: "Take what works for you. Go with the lowest dose and the shortest duration."

The "take what works for you" portion of that message refers to a quirk about analgesics that doctors can't currently explain, but nevertheless know is real. On an individual level, people respond better to some analgesics than others. Where acetaminophen is the bee's knees for some people, it does nothing for others. They may find naproxen does the trick for them.

Dr. David Henry of the Institute for Clinical Evaluative Sciences in Toronto advises the so-called "suck it and see" approach — try different kinds until you find something that does work for you. (Though you probably want to swallow, not suck, these pills.)

A few decades ago, it was all so much simpler.

Pharmaceutical giant Bayer had the ache-and-pain relief market sewn up with Aspirin, the brand name for the drug acetylsalicylic acid. The company even sold a children's formulation — baby Aspirin, which came in tiny pink chewable tablets.

But Aspirin's star began to fade when doctors discovered a nasty side-effect — the drug was very hard on the stomachs of people who took it.

"It really irritates the stomach lining, like no other drug in common use," Henry explains.

"I trained as a gastroenterologist. And if you put an endoscope down into someone's stomach and had a look after they've had a couple of doses of Aspirin, it's a lining that only a mother could love. It looks really bad."

It was also discovered that kids who took Aspirin when they had the flu or the chickenpox could develop Reye's syndrome, a sometimes fatal condition that attacks the brain and the liver. Aspirin is no longer recommended for children.

While Bayer Aspirin's distinctive yellow and brown boxes are still displayed among the products for sale on pain relief shelves of pharmacies, the drug is now mostly sold as a blood thinner used by seniors to lower their risk of heart attack.

As Aspirin fell out of favour, the market shifted to acetaminophen, sold as Tylenol in North America and Paracetomol in other parts of the world.

Later came medications known as non-steroidal anti-inflammatory drugs, or NSAIDs. There's ibuprofen, sold under the brand names like Advil and Motrin. Another is naproxen, sold as Aleve or Naprosyn.

Each has its pros and cons.

Acetaminophen is easier on the stomach than Aspirin and should probably be the choice of people who have or who are prone to stomach ulcers, Henry says. He suggests it may also be the safest pain relief option for pregnant women, if they have to take anything.

Mamdani agrees that the drug is pretty mild and a good starting place for people looking for pain relief. It may also be safer, from a heart-health point of view, than some of the other drugs, he says.

As well, acetaminophen doesn't have the same blood thinning powers that Aspirins and NSAIDs do. So someone told to avoid pain meds in advance of surgery or a procedure such as a colonoscopy might be able to use acetaminophen safely. (It's a good idea, though, to check with your doctor.)

People with asthma may find acetaminophen their best choice too. Aspirin and NSAIDs can aggravate asthma, Henry notes.

But one big negative with acetaminophen is the potential to damage critical internal organs. Too much of this drug can cause serious liver problems and kidney damage too. Henry says deaths due to accidental acetaminophen overdoses are not uncommon.

The potential for liver damage means acetaminophen and alcohol are an especially poor mix, Mamdani adds.

Ibuprofen and naproxen are NSAIDs, the non-steroidal anti-inflammatory drugs. As the name implies, they combat inflammation, which is helpful if you want to bring down the swelling on a sprained ankle or ease an achy back.

NSAIDs aren't as gentle on the stomach as acetaminophen, but they are easier to take than Aspirin. And of the two, ibuprofen is probably kinder to the stomach lining, Mamdani says.

On the other hand, naproxen is probably easier on the heart, which is something people with cardiovascular problems ought to consider, Henry notes. He co-authored a recent study looking at the risks analgesics pose to people with cardiovascular problems.

If you are taking naproxen, take it with food to protect the stomach, Mamdani warns.

Seniors and people who take Aspirin as a blood thinner need to choose an analgesic with care if they want to take one. That's because ibuprofen interacts with Aspirin, undermining the older drug's ability to play the blood thinning role. Henry says acetaminophen would be a safer bet.

But he says older, sicker people really ought to use these drugs with care. "People with heart and kidney complaints really need to consult their doctors before taking non-steroidal anti-inflammatory drugs."

Old or young, normally healthy or afflicted with chronic ailments, everyone ought to be careful about how many analgesics they take during cold and flu season, Mamdani and Henry agreed.

The over-the-counter cold and flu formulations — be they powders dissolved into hot water or pills — will all have one of these compounds in them already. Taking doses of analgesics on top of cold and flu meds is doubling up on the dose.