Long-Living Drugs

Nutrition labels tell us how many calories, carbohydrates and grams of fat and protein are in a serving, but few labels tell us how long the effect of a drug will last.

Taking a drug without knowing how and when your body will be affected -- and other pertinent informaton -- could be fatal.

Some drugs, such as the painkiller methadone, don't kick in right away, so anyone new to the drug is apt to take more and overdose.

Here is a list of drugs -- legal and illegal -- with their approximate half-life, which is the time it takes for the body to process half the drug.

For example, if you drink an 8-ounce cup of coffee, which contains 100 milligrams of caffeine, half of that amount will still be in your body about five hours later.

Note: The half-life times listed are approximations. They vary, depending on the strength of the drug and the dose, and on whether or not a tablet is slow- or immediate release.

Heroin: 30 minutes

Nicotine: 1 hour

Cocaine: 1 hour

Crystal methamphetamine: 1 hour

Acetaminophen (Tylenol): 2 hours

Morphine: 3 hours

Marijuana: 4 hours

OxyContin: 3 to 4.5 hours

Codeine: 4-6 hours

Coffee: 5 hours

Celecoxib (Celebrex): 11 hours

Methamphetamine: 12 hours

Methadone: 15-20 hours

Prozac: 7 days