Morphine
Morphine is a pain-killer extracted from the opium poppy. It is the most abundant. It is the most common alkaloid extracted from opium, the dried sap derived from slicing the unripe seedpods of the opium poppy. It's dependence liability is rated as high, and like in Mrs Dubose's case it is incredibly addictive. Morphine is regarded as the benchmark of painkillers to relieve severe pain. Like other opioids it acts directly on the central nervous system, physiological dependence taking several months to set in. Constipation, acute respiratory depression, renal failure, chemical toxicity, raised intercranial pressure and biliary colic (obstruction of the bile duct) is also a side effect.