Cleaning out the medicine cabinet is like cleaning out the fridge, but with a lot less "ewwws!"

The expired medications and health stuff you find may be years past the best-before date, but at least it's not leftovers covered in fuzzy green mould or foul-smelling, stomach-turning black slime.

The worst thing Kory Sloan of St. Albert, Alta., encountered while cleaning out his grandfather's cupboards was a bottle of really old pain-relieving tablets that smelled like vinegar. The smell is a sign the medication has gone bad.

Not that you should stick your nose into an expired container before deciding to chuck it out.

"The first thing they teach you in pharmacy school is don't put your nose into anything," says Edmonton pharmacist Ali Damani.

"If it's toxic, you could pass out from it."

Damani's advice is to wave a hand over the opened container to get a sniff of the air wafting out of it. But generally, checking the expiry date and eyeballing the contents is enough to tell you whether or not something needs to be tossed, he says.

There is, however, a growing body of research that finds some medicines remain potent beyond their expiry date. The leading evidence comes from a U.S. Food and Drug Administration program that tests drugs for the U.S. military. The results through July 2006 found 88 per cent of tested medicines remained potent for at least a year past expiration, and some for up to 14 years.

Still, some officials from the FDA, drug industry and research community, as well as pharmacists such as Damani, discourage taking expired drugs, because they're not a sure thing.

"Yes, some medications are totally stable past the expiry date, but that's based on a medication sitting in a sealed bottle on a shelf at perfect conditions," he says.

The other thing is, if the potency isn't there for an expired headache medication and you end up taking one and it doesn't work, and you take a second one, maybe even a third, you don't know what dose you've taken, and there are specific limits over time, Damani says.

For example, the maximum amount of Tylenol you can take in six hours is about 1,000 mg or two extra-strength Tylenols.

"That's as much as the liver can process," he says. "Not everybody is a physician or pharmacist or they don't have that background where they know that or can make an assessment.

"If you don't know, then why would you want to guess or try it?"

This is especially true with expired drugs designed to cure illness or control a chronic condition.

Drugs that degrade quickly, such as nitroglycerine, liquid antibiotics, insulin, blood thinners, anti-convulsants, oral contraceptives and eye drops should never be used beyond the best-before date.

That's why it's important for people to cull their medications on a regular basis, not only for their own safety, but for the safety of other people in the home, particularly children, Damani says.

So starting now, the pharmacist recommends including the medicine cabinet in your annual spring cleaning.

First thing, remove all medications from the medicine cabinet. Store them somewhere out of reach of children and pets, such as a hallway closet or pantry, in a covered plastic container, on a high shelf.

Damani used to keep medication in the bathroom medicine cabinet, too, he says, until he got to pharmacy school and found out that it's actually the worst location, because changes in humidity and temperature from showers and steam really degrade medication. (The same thing is true for cosmetics.)

The expiration date means the medication will be effective until that date, if stored under the proper conditions of light, temperature and moisture. If not stored under suggested conditions, medicine may expire before the expiration date.

The expiration date on most medications is two years after the drug is manufactured.

Once you've found a cool, dry storage place, start going through your medications, following these rules:

1) Remove anything with an expired date or no expiry date that you can't remember buying.

2) Remove any medications that haven't expired but that don't look good or smell good, including pills that have partially crumbled into powder or liquids that have changed appearance or odour.

3) Remove all leftover prescription meds, even if they haven't expired, if you're not taking them anymore.

"Different medications can have different effects when they come close to expiry or after expiry," Damani says. "For example, antibiotics like tetracycline, if used soon after expiry, can actually be toxic."

It's hard for anyone to tell if such medication is toxic or if it's just lost its potency over time, which can be dangerous for someone with a health condition controlled with exact doses of prescription drugs.

If in doubt, it's better to throw it out, Damani says. But don't actually "throw" it out.

Medicines are considered hazardous waste and, when thrown in the garbage, can leach into the soil, creating an environmental hazard.

Flushing them down the toilet can contaminate water supplies. In fact, traces of certain medications have been found in some drinking water.

The safest way to get rid of medication is to take it to a pharmacy for proper disposal.

Many pharmacies have an ongoing program to accept unwanted medications or run periodic drives to collect expired medicine.

Damani says it's hard for some people, who have spent a lot of money on medications, to throw them away just because they're expired or they're not taking them anymore.

"But better safety first," he counsels.