Prescription Cough Syrup
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If your doctor puts you on a potent prescription cough syrup for bronchitis, sinusitis, or hay fever, be careful with it. "The 'good stuff' has codeine, an opiate, which you can get hooked on," Maxwell says. It can also be lethal when used in excessive amounts. This is the drug that landed Lil Wayne in the hospital last year and what the police just found at Bieber's place.

Make sure you take only the recommended doses to avoid becoming dependent. Also, never drink booze while taking prescription cough syrup. Along with codeine, it contains a strong antihistamine called promethazine and the antihistamine-codeine-alcohol trifecta can cause you to stop breathing.