Common Effects of Morphine

Morphine sulfate, derived from opium, belongs to a class of drugs known as narcotic analgesics (narcotic pain-killers) that are used for treating moderate to severe pain. This medication is a strong narcotic that frequently is given following acute injuries or post-operative pain right after surgery. This drug works on the central nervous system by binding with receptors in the brain that results in altering one’s perception of pain, which then reduces one’s subjective pain experience. This pain medicine is available in both short and long-acting prescription forms.

Common Side Effects

Morphine is a narcotic, so this drug has sedative properties. Common side effects associated with morphine include drowsiness, lightheadedness and possible fainting. This means then that you should not do tasks that involve machinery or anything that could be dangerous until you know how this medication affects you. Morphine can lower blood pressure (hypotension), which can play a role in experiencing the side effects of dizziness and headaches. Other commonly reported side effects are stomach problems, sweating and trouble sleeping.

Gastrointestinal Effects

Some side effects that you may experience include abdominal pain as well as nausea and vomiting or diarrhea. One will likely experience some constipation problems to the point that eating habits will need to be changed, such as adding more fiber or fruits to the diet. If one experiences several bouts of vomiting and diarrhea, then keeping hydrated with fluids is important to avoid becoming dehydrated.

Addictive Effects

As a narcotic, morphine has the potential to be habit-forming or addictive; therefore, supervision is needed, especially if a patient takes this drug for a long period of time. Also, in the case of long-term use, there is a risk for increased tolerance, which means that increasingly higher amounts of the drug are needed to produce the same effect (pain relief). Therefore, if one has a history of chemical abuse or addiction, the prescribing physician must receive a complete medical history in order to make appropriate decisions for the patient’s well-being.

Respiratory Depression

A major concern with opioid analgesics is that they can seriously affect the respiratory system by what is known as respiratory depression; this means that breathing gets shallow and slows down considerably. This is a dangerous situation where emergency medical care is required.

About this Author

A.M. Tacon is an associate professor of health at Texas Tech University. Research interests include psychosocial factors in cancer, complementary therapies, and stress reduction in individuals with cancer. Dr. Tacon runs mindfulness-based stress reduction programs for women with breast cancer, which is based on various forms of mindfulness meditation.