A Guide to Morphine

By The Fix staff 08/02/14

Morphine is an opiate analgesic (pain killer) that is naturally found in the opium poppy. It is the most abundant alkaloid found in opium and comprises  8%-19% of the dry weight of opium. Routes of administration include: inhalation (smoking), oral, rectal, insufflation (snorting), subcutaneous, intramuscular, intravenous, and intrathecal (injection into the spinal canal). Common forms include: Oramorph, MS Contin, Avinza, Kadian, Roxanol, M.O.S.-Sulfate, Morphine Sulphate, Infumorph, and Duramorph. Street names include: M, Miss Emma, Morph, misties, greys (100 mg MS Contin extended release), and red rockets (200 mg MS Contin extended release). 

How it affects the brain and body 

Morphine acts in the same way as the brain’s endorphins and binds to opiate receptors connected to pain, movement and emotion. Morphine causes feelings of euphoria, increased warmth, drowsiness, limb heaviness and a sense of floating. It also causes histamine to be released which can result in itchiness of the extremities. Nausea is common as it immediately stimulates the brain’s chemoreceptor trigger zone which controls regurgitation. Along with this it directly affects the respiratory centers of the brain stem, depressing respiration and inducing coughing. Blood pressure and heart rate are not affected while in stationary reclining positions but sudden movement from prone to standing can cause blood pressure to drop.

The effects of morphine can last anywhere from four to six hours.

Medical Uses

Until fairly recently morphine was considered something of the gold standard for moderate to severe pain relief, including from heart attacks. 

Addictive Properties

Morphine has a higher dependence liability than other opioid analgesics in common use because it causes a sense of pleasure and reward. Moreover, tolerance to morphine increases in patients and addicted users, requiring more of the drug to achieve either relief or to get high. Recent research shows that a single dose of morphine can lead to addiction.

Long Term Effects of Use

Long term effects include fainting, seizures, a blue tinge to the skin, rashes and difficulty breathing. Detoxification for long term users also has a fatality potential.


Overdose symptoms include constricted pupils, decreased awareness, fever, increased blood pressure, increased thirst, lower back or side pain, muscle cramps or spasms, no muscle tone or movement, and swelling of the face, fingers or lower legs. The risk of coma is extremely high. The most common deaths with overdose result from respiratory arrest.

Legal Status

Morphine is considered a Schedule II drug in the United States and a Schedule I internationally.









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