tramadol, codeine (Tylenol 1, Tylenol 2, Tylenol 3), hydrocodone (vicodin), dihydrocodeine (dhc), oxycodone (percocet, oxycontin, etc), morphine, hydromorphone (dilaudid), oxymorphone (opana), meperidine (demerol), fentanyl (actiq, etc), buprenorphine (suboxone/subutex), methadone, and in some countries diacetylmorphine (heroin/diamorphine -- for cancer pain)
opium tinctures are still, very rarely, prescribed in the united states. immodium is also technically an opioid. kratom isn't prescribed, but has opioid effects, as does myrrh to some extent.
There may be others, but I don't remember them at the moment. There are also analogues of the above substances.
Alcohol is the most widely abused depressant.
indicators show that hydrocodone is the most commonly abused narcotic analgesic
Marijuana.
oxycontin
Alcohol is the oldest drug known to man, and also the most widely-used drug. So, I would imagine it is the most widely-abused drug, as well.
No. Narcotics are drugs that are abused, or have addiction potential. Naloxone is sometimes an ingredient in narcotic preparation, but it alone has no narcotic features.
marijuana.
Dogs, Cats, and horses are the most widely-known species of animals that are abused nowadays.
Ketamine
By a substantial margin, alcohol is the most widely abused drug in every age group—including children. However, marijuana is the most widely used illicit substance among all age groups, but “club” drug use is increasing.
Crack cocaine and nicotine, in that order.
Alcohol is the most common substance abuse in the world. It is widely consumed and can lead to various health and social issues when abused.