The Long-Term Effects of Morphine

Morphine is a narcotic pain reliever classed as an opiate, which is the strongest kind of pain reliever available. Morphine can be used in the short term to relieve severe acute pain, or in the long term to manage chronic pain. Morphine is available as a pill, capsule, suspension or injection. Long-term effects of morphine involve the central nervous system, the gastrointestinal system and the urogenital system, causing multiple side effects.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


A., Shannon, T. M., & Shields, K. M.; 2010'). Opioids decrease gastric motility--the natural movement of contents through the intestine--resulting in constipation. This can be minimized by drinking adequate amounts of water, eating a high-fiber diet, exercising regularly and using stool softeners as directed by your physician.

Decreased Libido

Jennifer Schneider, MD, Ph.D., explains that some men on high doses of long-term morphine may experience decreased testosterone levels. This can cause decreased libido and decreased potency. However, testosterone replacement therapy can alleviate this problem.

Physical Dependence

Because morphine affects the central nervous system, sudden removal of the drug can cause physical symptoms of withdrawal. Morphine affects a person’s respiratory rate, heart rate and blood pressure, gastrointestinal system, and mental state. Withdrawal symptoms can begin from 6 to 12 hours after abruptly stopping morphine, and peak in one to three days. Tapering off can prevent withdrawal symptoms.


Addiction is a psychological and behavioral phenomenon. It's not the same thing as physical dependence. A person who is addicted to morphine has three characteristic traits: compulsive use, continuing use of the drug despite bad consequences, and an obsession or preoccupation with getting and using more morphine. As morphine addiction worsens, the person’s life becomes more consumed with the drug. Relationships suffer, and the person’s life is constricted or limited. This is the opposite of what happens to a patient who uses morphine for pain relief. A person who gets pain relief from morphine has a more active life. He engages with family and friends, and is able to participate in activities that he could not perform before because of the limiting effects of pain.