Beginning of Essay
: is readily absorbed from the gastrointestinal tract. It is rapidly distributed from the intravascular spaces to the various body tissues, with preferential uptake by parenchymatous organs such as the liver, spleen and kidney. crosses the blood-brain barrier, a ....

Middle of Essay
.... used with aspirin and sometimes caffeine. WHEN should it be used? Codeine is usually taken every four to six hours as needed. Follow the directions on your prescription label carefully, and ask your pharmacist or doctor to explain any part that you do not understand. HOW should it be used? Codeine is available, alone or with other medications, in tablets, capsules, and liquid to be taken by mouth. Your prescription label tells you how much to take at each dose. The liquid should be shaken well before each use to mix the medicine evenly. Ask your pharmacist for a specially marked measuring spoon to be sure of an accurate dose. Do not take more o ....