What Is Morphine?

Morphine is an opioid medication used for pain management. It is used in the treatment of moderate to severe pain. Extended release forms of morphine are used to manage pain for long periods of time. Short acting forms of morphine are intended to be used for pain as needed.

How Does Morphine Work?

After morphine is administered, it is absorbed into the bloodstream. It works within the central nervous system, affecting several different receptors. It can be taken orally, intravenously, or rectally. The time is which morphine takes to work depends on the route of administration. Intravenous morphine injections work almost instantly, but it generally takes 15-60 minutes to feel the effects, which can last from 1.5-7 hours.

What Are the Side-Effects of Morphine?

There are several side effects that people may experience when taking morphine. Some of the most common side effects of taking this medication may go away once the body adjusts to it. These include:

  • Constipation
  • Cramps
  • Feeling calm
  • Drowsiness
  • Feeling sleepy
  • Weight loss

Serious Side Effects of Morphine

There are also more serious side effects associated with the use of morphine. Anyone experiencing any of the following symptoms should seek medical attention immediately:

  • Blurred vision
  • Extreme stomach pain
  • Change in the ability to see the colours blue or yellow
  • Decreased urination
  • Extreme constipation
  • Black, tarry bowel movements
  • Rash or hives
  • Chest pain
  • Irregular heartbeat (fast or slow)
  • Increased sweating
  • Severe vomiting
  • Itching, crawling, or burning skin
  • Swelling of the eyes, lips, face, or tongue
  • Bulging soft spot on the head of an infant

Morphine also runs the risk of overdose. Symptoms of overdose that require immediate emergency attention can include:

  • Decreased responsiveness
  • Loss of awareness
  • Extreme drowsiness
  • Muscle spasms or cramps
  • Severe drowsiness
  • Extreme sleepiness
  • Loss of muscle movement
  • Lower back pain
  • Side pain
  • Swelling in the face, fingers, or lower legs


When morphine is taken for extended periods of time, both psychological and physical dependence can occur. While not everyone who takes morphine will become addicted to it, there is the potential of developing a dependence. Risk for morphine dependence is higher amongst individuals with a personal or family history of drug or alcohol abuse.

When a person has developed a tolerance to morphine (either through prescribed or illicit use), they will experience withdrawal symptoms when they attempt to stop taking the drug. Withdrawal symptoms of morphine can begin as soon as effectiveness in the bloodstream stops. Withdrawal occurs in two separate phases, the first typically 6-12 hours after a person’s last dose. Early withdrawal symptoms can include:

  • Yawning
  • Sweating
  • Runny nose
  • Tearing

Peak symptoms are when a person experiences the more severe withdrawal symptoms. This occurs approximately 48-72 hours after a person’s last dose. These can include:

  • Chills
  • Sneezing
  • Nausea
  • Vomiting
  • Diarrhoea
  • Tremors
  • Restlessness
  • Anxiety
  • Depression
  • Extreme cravings

Withdrawal from morphine typically lasts 5-7 days. The severity of symptoms a person experience is highly individualised, depending on the amount of they use, how often they use, and how long they have been using. A history of drug or alcohol abuse will also affect the length and severity of morphine withdrawal.


People experiencing a dependence to morphine can benefit by getting professional addiction treatment. There are several treatment options for a person to choose from including professional detox, and outpatient or residential rehab. For moderate to severe instances of morphine addiction, a comprehensive programme that includes assisted detox, therapy, and various addiction treatments has shown to be beneficial.

External Links

Detoxing from Morphine: Timelines and Symptoms, American Addiction Centers

Frequently asked questions about morphine, St Christopher’s, 2017

Morphine (Oral Route), Mayo Foundation for Medical Education and Research (MFMER)

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