Medication Information
Impact of medications on people with SCI/D
Damage to the spinal cord can affect usual body processes, including how your organs function. Medications may affect people with SCI/D Spinal cord injury or dysfunction. differently than the general population because of the changes to usual processes and functions in the body, such as:
- Altered pharmacokinetics The study of how drugs move into, through and out of the body. (what the body does to the medication)
- Changes to respiratory function How well a person’s lungs and breathing system works.
- Increased potential for constipation
- Autonomic dysreflexia Health condition that affects individuals with a spinal cord injury at or above the T6 level. This syndrome involves an overreaction of the nervous system and can cause high blood pressure resulting in a headache, sweating, blotchy skin, and bladder and bowel problems. (overreaction of the nervous system)
Pharmacokinetics
This video describes pharmacokinetics The study of how drugs move into, through and out of the body. and how it may be impacted in people with SCI/D Spinal cord injury or dysfunction. . This information is also presented below.
Pharmacokinetics The study of how drugs move into, through and out of the body. can be understood as what the body does to a medication (or the medication’s journey through the body).
There are four main steps to this journey: absorption Movement of the drug from the site of administration to the bloodstream or site of action. Absorption is affected by how the medication is taken (e.g., orally, topically, injected, inhaled). , distribution Refers to how the medication moves through the body’s bloodstream and tissues. , metabolism Metabolism refers to the breaking down of a medication to be removed from the body. , and excretion How a medication is removed from the body. .
- Absorption
Movement of the drug from the site of administration to the bloodstream or site of action. Absorption is affected by how the medication is taken (e.g., orally, topically, injected, inhaled).
: How will the medication get in?
- Medication absorption Movement of the drug from the site of administration to the bloodstream or site of action. Absorption is affected by how the medication is taken (e.g., orally, topically, injected, inhaled). refers to the movement of the medication from where it is administered into the bloodstream.
- Absorption Movement of the drug from the site of administration to the bloodstream or site of action. Absorption is affected by how the medication is taken (e.g., orally, topically, injected, inhaled). is affected by how the medication is taken (oral, topical, injection, inhalation, etc.).
- Distribution
Refers to how the medication moves through the body’s bloodstream and tissues.
: Where will the medication go?
- Distribution Refers to how the medication moves through the body’s bloodstream and tissues. refers to a medication moving through the body’s bloodstream and tissues.
- SCI/D Spinal cord injury or dysfunction. can affect blood flow through the spinal cord and to different organs and tissues.
- If blood flow and/or body composition (e.g., body fat) are affected after experiencing SCI/D Spinal cord injury or dysfunction. , the distribution Refers to how the medication moves through the body’s bloodstream and tissues. of medications through the body may also be affected.
- Metabolism
Metabolism refers to the breaking down of a medication to be removed from the body.
: How will the medication be broken down?
- Metabolism Metabolism refers to the breaking down of a medication to be removed from the body. refers to the process of a person’s body breaking down the medications they take to be removed from the body.
- The liver is primary place of medication metabolism Metabolism refers to the breaking down of a medication to be removed from the body. and where many medication interactions A reaction between two or more drugs, or between a drug and food, drink or supplement. A medication interaction can delay, decrease or increase the action that can prevent the drug from performing as expected. take place. Any changes to liver function (typically due to changes in blood flow), which can occur post-SCI/D Spinal cord injury or dysfunction. , can affect how medications are broken down.
- Excretion
How a medication is removed from the body.
: How will the medication leave?
- Excretion How a medication is removed from the body. refers to how the medication is removed from the body.
- Changes in kidney and liver function, which can occur following SCI/D Spinal cord injury or dysfunction. , can affect medications that are both processed and eliminated by those organs.
- For example, baclofen is usually taken orally as a tablet. It undergoes metabolism Metabolism refers to the breaking down of a medication to be removed from the body. in the liver and is excreted through the kidneys in the urine.
Respiratory Function
- Following SCI/D Spinal cord injury or dysfunction. , a change to an individual’s respiratory function How well a person’s lungs and breathing system works. (e.g., breathing, coughing, changing lung volume, weakening muscles) can occur. This typically happens following higher level injuries.
- Some medications, such as opioids Class of pain-relieving medication that work by blocking pain signals in the brain. Examples include drugs like morphine, oxycodone, and fentanyl. , can cause breathing to become slow and shallow (depressed respiratory function How well a person’s lungs and breathing system works. ). This can potentially worsen respiratory issues if individuals are already experiencing changes in their respiratory function How well a person’s lungs and breathing system works. post SCI/D Spinal cord injury or dysfunction. .
Constipation
- Following SCI/D Spinal cord injury or dysfunction. , a change to one’s bowel function can occur. This is often due to damaged nerves, which disrupts signals between the brain and muscles of the bowel. It can also be worsened by decreased mobility, changes to reflexes that regulate bowel movements, and changes to muscle tone.
- Some medications, including opioids Class of pain-relieving medication that work by blocking pain signals in the brain. Examples include drugs like morphine, oxycodone, and fentanyl. , can cause constipation as a side effect. This can potentially worsen the issue if individuals are already experiencing constipation post-SCI/D Spinal cord injury or dysfunction. .
- Note: There are a variety of options for managing constipation, including prescription medications A medication that is only available with written instructions from a healthcare provider (e.g., doctor, dentist, pharmacist). , non-prescription medications Medications that you can get without a prescription. May include over-the-counter medications and natural health products. , and alternative options (e.g., diet, exercise, stimulation). It is important to talk with your healthcare team about your preferences and potential treatment options.
Autonomic Dysreflexia

- Autonomic dysreflexia
Health condition that affects individuals with a spinal cord injury at or above the T6 level. This syndrome involves an overreaction of the nervous system and can cause high blood pressure resulting in a headache, sweating, blotchy skin, and bladder and bowel problems.
(sometimes referred to as autonomic hyperreflexia) is an overreaction of the nervous system. Individuals may experience one or more of the following symptoms:
- High blood pressure
- Sweating
- Skin flushing
- Headaches
- Confusion
- Anxiety
- Note: You can have autonomic dysreflexia Health condition that affects individuals with a spinal cord injury at or above the T6 level. This syndrome involves an overreaction of the nervous system and can cause high blood pressure resulting in a headache, sweating, blotchy skin, and bladder and bowel problems. without experiencing any symptoms, so it is recommended to monitor your blood pressure regularly. It is recommended to have a blood pressure cuff, thermometer, and oximeter at home to help monitor some of these potential symptoms.
- Autonomic dysreflexia Health condition that affects individuals with a spinal cord injury at or above the T6 level. This syndrome involves an overreaction of the nervous system and can cause high blood pressure resulting in a headache, sweating, blotchy skin, and bladder and bowel problems. is a condition that can commonly occur following SCI/D Spinal cord injury or dysfunction. , usually when the injury occurs above the T6 level. Autonomic dysreflexia Health condition that affects individuals with a spinal cord injury at or above the T6 level. This syndrome involves an overreaction of the nervous system and can cause high blood pressure resulting in a headache, sweating, blotchy skin, and bladder and bowel problems. is often triggered by a signal (stimulus) below the level of injury (e.g., pain, bladder or bowel distension, fracture, menstruation, pressure injury).
- Some medications can affect blood pressure, and should be monitored, especially if you have an injury above T6 and have had symptoms of autonomic dysreflexia Health condition that affects individuals with a spinal cord injury at or above the T6 level. This syndrome involves an overreaction of the nervous system and can cause high blood pressure resulting in a headache, sweating, blotchy skin, and bladder and bowel problems. .
Depending on the level and completeness of the injury, medications may affect people with SCI/D Spinal cord injury or dysfunction. differently than the general population through altered pharmacokinetics The study of how drugs move into, through and out of the body. , changes to respiratory function How well a person’s lungs and breathing system works. , and increased potential for constipation and autonomic dysreflexia Health condition that affects individuals with a spinal cord injury at or above the T6 level. This syndrome involves an overreaction of the nervous system and can cause high blood pressure resulting in a headache, sweating, blotchy skin, and bladder and bowel problems. .
When taking medications, it is important to discuss these potential impacts with your healthcare providers to ensure you are both aware and monitoring your body’s response to your medications.
References
Boom, M., Niesters, M., Sarton, E., Aarts, L., W. Smith, T., & Dahan, A. (2012). Non-analgesic effects of opioids Class of pain-relieving medication that work by blocking pain signals in the brain. Examples include drugs like morphine, oxycodone, and fentanyl. : Opioid-induced respiratory depression A slow, shallow breathing rate preventing carbon dioxide and oxygen exchange in the body. Can be caused by taking toxic amounts of certain medication or combinations of medications. . Current Pharmaceutical Design, 18(37), 5994–6004. https://doi.org/10.2174/138161212803582469
Bryce, T. N. (2018). Opioids Class of pain-relieving medication that work by blocking pain signals in the brain. Examples include drugs like morphine, oxycodone, and fentanyl. should not be prescribed for chronic pain Pain that lasts longer than 3 months and continues after an injury or illness. after Spinal Cord Injury. Spinal Cord Series and Cases, 4(1). https://doi.org/10.1038/s41394-018-0095-2
Genomind, G. (2022, December 19). Introduction to pharmacokinetics The study of how drugs move into, through and out of the body. : Four steps in a drug’s journey through the body. https://genomind.com/providers/introduction-to-pharmacokinetics-four-steps-in-a-drugs-journey-through-the-body/
Mestre, H., Alkon, T., Salazar, S., & Ibarra, A. (2011). Spinal cord injury sequelae alter drug pharmacokinetics The study of how drugs move into, through and out of the body. : An overview. Spinal Cord, 49(9), 955–960. https://doi.org/10.1038/sc.2011.58
Model Systems Knowledge Translation Center. (2015). Respiratory health and spinal cord injury. https://msktc.org/sci/factsheets/respiratory-health-and-spinal-cord-injury
Model Systems Knowledge Translation Center. (2021, January). Opioids Class of pain-relieving medication that work by blocking pain signals in the brain. Examples include drugs like morphine, oxycodone, and fentanyl. and Your Health. https://msktc.org/sites/default/files/SCI-OpioidsYourHealthFS-508.pdf