Morphine effects

A research backed synopsis of morphine’s effects on the body, brain, organ systems, behavior, and fertility and pregnancy. Learn how morphine affects the organism of long-term, chronic users and what are the potential risks.

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Morphine is a very powerful painkiller, but also a notorious one. The negative effects of morphine can result in physical problems and addiction.

More on the effects of morphine here. At the end, we invite you to post your questions and comments. We try to personally and promptly respond to all legitimate inquiries.

Morphine effects on the body

One of the first effects on the body that you can expect after frequent morphine use is tolerance. This means you need more of the drug in order for it to be as effective as it was at the beginning of use. In fact, tis therapeutic strength tends to diminish over time and after regular use. This is one reason why people dose more frequently or at increased amounts.

Frequent use also leads to physical dependence to morphine which happens when the body gets used to the presence of morphine. Dependence is a chemical adaptation to morphine that happens mainly in the central nervous system of the brain and spinal cord. You know you’ve developed dependence when you experience withdrawal symptoms when the dose is tapered or stopped. Morphine withdrawal symptoms can vary from mild to severe and may include:

  • cold flashes
  • diarrhea
  • nausea
  • pain in the muscles and bones
  • restlessness
  • trouble sleeping
  • vomiting

It’s important to distinguish between physical dependence and addiction, which do not necessarily go hand in hand. The latter has to do with how the person thinks of the drug, while the former is how the body feels and responds to the presence and absence of the drug.

Morphine effects on the brain

Morphine directly targets the central nervous system (CNS) and changes the way in which the body feels and responds to pain. More precisely, it binds to opiate receptors in the brain and changes the neurochemical activity in the brain stem which can result in alteration of the automatic body functions.

Morphine also affects regions in the brain responsible for pleasure. With regular use, the brain starts to register the effects of the morphine as a reward. This is when an individual begins to seek morphine for purposes other than pain relief and develops addiction to its effects. That said, over time (and due to its powerful effect) morphine eventually affects the brain by creating addiction to its pleasurable effects.

Morphine effects on the heart

Morphine can depress the heart rate and lead to a life-threatening situation if taken in doses more than prescribed. Furthermore, elevated heart rate may occur upon withdrawal from morphine. It is important to address any heart-related problems prior to starting a morphine therapy in order to avoid any further complications.

Morphine effects on the liver

Morphine is metabolized mainly in the liver and may cause liver damage if used in routes, frequency, and dosage other than prescribed. Developing chronic liver infection and disease are possible side effects of long term morphine use.

Morphine effects on the lungs

Morphine may negatively affect the respiratory system. In fact, morphine induced respiratory depression may be one of the most dangerous side effects that can lead to:

  • acute lung injury
  • apnea
  • hypoxia
  • pneumonia

…and other pulmonary complications.

Morphine effects on personality and behavior

Morphine users exhibit euphoric and elated behavior which may alter the way they perceive risky situations. Following the morphine “high” a user is likely to exhibit signs of:

  • concentration problems
  • destructibility
  • fatigue
  • general psychomotor impairment
  • inattentiveness
  • mood swing
  • poor performance
  • slower reaction time

Altered personality is typical for morphine addicts since they become obsessed with obtaining and using morphine and may neglect things that had mattered before.

Morphine effects on blood pressure

Morphine decreases blood pressure and may result in severe hypotension if taken in higher doses. People with low blood pressure should be extremely cautions when using morphine.

Morphine effects on skin

The skin may be affected by morphine in various ways. Flushing of the face and neck typically occur along with the initial euphoria, while cold and clammy skin with bluish fingernails and lips is a common signs of morphine overdose. Some case reports describe skin reactions such as:

  • urticaria
  • pruritus
  • contact dermatitis
  • irritation associated with morphine use

Morphine effects on sperm

According to a case report, there may be a correlation between morphine use and morphologically abnormal testicles as well as decrease of the sperm motility which may lead to or increase the risk of fertility issues.

Morphine effects on pregnancy

What are the long term effects of morphine on sex and pregnancy? Morphine may not be safe for use during pregnancy as it could cause fetal harm. It is not recommended for pregnant women or those who are intending to become pregnant unless the benefits of its use overweight the potential risks.

Morphine effects on a fetus

Considering that morphine reaches the fetus through the placenta, there is a possibility of fetal adverse effects. Studies report that regular use of morphine during pregnancy may harm the fetus by causing physical and neurobehavioral defects. Moreover, the baby may experience withdrawal symptoms upon birth, some of which may be serious or even life-threatening.

Most common symptoms seen in babies born to mothers using methadone during pregnancy include:

  • irritability
  • hyperactivity
  • troubled sleep
  • excessive crying
  • shaking of a part of the body
  • vomiting
  • diarrhea
  • inability to gain weight

Morphine effects on dopamine

Morphine affects the mesolimbic hyperactivation of the dopaminergic pathways, the outcome of which is increased locomotor activity and feelings of pleasure and wellbeing.

Morphine effects on breast milk

Traces of morphine are commonly detected in the breast milk of women using morphine. According to studies, the amount of morphine that could be transferred by nursing is considerably small and so are the chances of harming the nursing child.

Morphine effects on the nervous system

Morphine targets the central nervous system (CNS) and blocks the pain receptors, thus relieving sensations of pain. The interaction of morphine with the CNS may result in:

  • agitation
  • depression
  • delirium
  • dizziness
  • insomnia
  • lethargy
  • mental clouding
  • nervousness
  • sedation
  • seizures
  • weakness
  • …and even coma

Morphine effects on the nose, ears, and throat

Runny nose is a common withdrawal symptoms of methadone use, while swollen throat may indicate an allergic reaction.

Morphine effects on eyes and pupils

Swelling of the eyes is a possible side effect of morphine use. On the other hand, “watery eyes” is a common withdrawal symptom, while pinpoint pupils suggest a potential overdose on morphine.

Morphine effects on blood sugar

Studies suggest that the blood sugar levels may increase after initial use, but conclude that continuous morphine use has no suppressing effect on blood sugar.

Morphine effects questions

Do you still have questions about morphine use and its effects? Please let us know in the comment section below and we will try to respond to each query personally and promptly.

Reference sources: NCBI: Liver and kidney toxicity in chronic use of opioids
NCBI: Effect of chronic pain on morphine-induced respiratory depression in mice
NCBI: Proenkephalin transgenic mice: a short promoter confers high testis expression and reduced fertility
NCBI: Regulation of Male Fertility by the Opioid System
NCBI: The Effect of Opium Dependency of Parent (s) on Offspring’s Spatial Learning & Memory in Adult Male Rats
NCBI: Excretion of morphine in human breast milk
NHTSA: Morphine (and Heroin)
NIDA: Misuse of Prescription Drugs
NLM: Morphine overdose
NLM: Morphine
NLM: Morphine
TOXNET: Morphine
About the author
Lee Weber is a published author, medical writer, and woman in long-term recovery from addiction. Her latest book, The Definitive Guide to Addiction Interventions is set to reach university bookstores in early 2019.
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