Morphine, a narcotic, acts directly on the central nervous system. Besides relieving pain, it impairs mental and physical performance, relieves fear and anxiety, and produces euphoria. It also decreases hunger, inhibits the cough reflex, produces constipation, and usually reduces the sex drive; in women it may interfere with the menstrual cycle.
Morphine is highly addictive. Tolerance (the need for higher and higher doses to maintain the same effect) and physical and psychological dependence develop quickly. Withdrawal from morphine causes nausea, tearing, yawning, chills, and sweating lasting up to three days. Morphine crosses the placental barrier, and babies born to morphine-using mothers go through withdrawal.
Today morphine is used medicinally for severe pain, cough suppression, and sometimes before surgery. It is seldom used illicitly except by doctors and other medical personnel who have access to the drug. It is injected, taken orally or inhaled, or taken through rectal suppositories. Methadone treatment has been useful in curing morphine addiction.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.