Opioid addiction and chronic pain: Long term effects

There are a number of common side effects of opiate use including feelings of euphoria, feeling spaced out and ‘high’, and drowsiness.  According to the RCOA, between 50% and 80% of patients in clinical trials experience at least one side effect from opioid therapy.

“Evidence shows that chronic opioid therapy is associated with constipation, sleep-disordered breathing, fractures, hypothalamic-pituitary-adrenal dysregulation, and overdose… Opioid-related adverse effects can cause significant declines in health-related quality of life and increased health care costs.”
A Review of Potential Adverse Effects of Long-Term Opioid Therapy: A Practitioner’s Guide

To understand the effects of long term use, you need to know that opiates work by depressing everything, including the pain, but also natural bodily functions such as breathing, blood pressure, heart rate and alertness.

Breathing

In terms of breathing, there are a number of ways that opiates affect this vital function.  They slow down your breathing, they are associated with central sleep apnea, atiaxic breathing hypoxemia and carbon dioxide retention.

Let’s bring in some definitions to help explain what these terms actually mean for the patient:

  • Central Sleep Apnea: pauses in breathing while asleep during which the body does not attempt to breathe. A certain number of pauses in sleep are normal but with CSA, the pauses are longer and more frequent and are the result of the brain not sending the right signals to the muscles related to breathing.
  • Ataxic Breathing: an irregular, uncoordinated breathing pattern.
  • Hypoxemia: Low blood oxygen which can cause low oxygen levels in your tissues.
  • Carbon Dioxide Retention: abnormally high levels of carbon dioxide in the blood.

Essentially, breathing is no longer an automatic reflex.  All of these can lead to additional health issues, for example if you aren’t getting enough oxygen there is a risk of brain damage as well as damage to other vital organs.  Deprived of oxygen over a period of time can result in organs shutting down and for some patients, their breathing is so depressed that they fail to wake when they don’t breathe.  It is this, and organ failure, that is behind many opioid overdoses and deaths.

For patients on around the clock opiates for at least six months, sleep disordered breathing issues were found to be as high as 75%, as opposed to 3-20% in the general population.  These effects appear to be related to the dose strength, with ataxic breathing observed in 92% of people taking a morphine equivalent dose of 200mg, 61% of people taking under 200mg and 5% of people not taking opioids.

We will see the effects on the brains performance when we consider the mental effects of long term use.

Gastrointestinal

Just as the breathing system is slowed down, so too is the gastrointestinal system.  The urge to pass stools reduces causing constipation and even impacted bowels.  Opiate use can also cause vomiting, cramping and bloating.

Hormones

One of the things that shocked me when I was looking into the effects of opiates was the impact on the hormonal system.

When you think hormones you tend to think sex so I’m going to start there.  Opiate use can decrease your sex drive, can cause infertility, can cause erectile dysfunction and can cause issues with menstruation.  Fatigue and hot flashes, inappropriate milk production can also occur.

Hormones are also involved in other bodily functions and can affect bone density causing osteoporosis and impaired healing.  Growth hormones, thyroid stimulating hormones and many others are also affected.

Mental

As an organ, your brain is affected and thus your mental wellbeing and functions are impaired.  Opiate use can cause confusion, lack of concentration, drowsiness, depressed alertness, depression and other mental illness.

As the person’s judgement is affected, they can make decisions that they wouldn’t otherwise.  There are impulse control issues as well as impaired insight and issues with reasoning.  Demotivation and apathy can lead to social withdrawal and the persons world can become smaller and smaller.  Moodswings, hostility, increased secrecy and a change in personality can all come about because of opioid use.

Due to the reduced oxygen levels, the brain struggles to perform even basic tasks (such as breathing) and the person can experience agitation and disorientation. Impaired memory is another common effect.

Muscular skeletal

The combination of the confusion and the bone density issues, muscular skeletal issues are common.  Impaired coordination can lead to an increased fall risk, as can dizziness and a sedative effect.  When falls occur, fractures are more likely.

Hyperalgesia

Possibly one of the most counterintuitive effects of long term opioid use is hyperalgesia, that is a heightened sensitivity to pain.  This feels like the most insidious of the effects as it likely leads to more opiate use and makes the whole situation worse…

Pain associated with hyperalgesia tends to be more diffuse than the pre-existing pain and less defined.

Other

Other effects include a reduced immune system responsive, slurred and slow speech, falling asleep mid conversation and not realising it, blackouts and forgetfulness.  Increased sensitivity to sights, sounds and emotions may also be present.  Dry mouth that can cause tooth decay is yet another possible effect as is a suppressed cough reflex.

Whilst one person is unlikely to experience all of these effects, in general the risk increases as the dose increases. Please do not let this put you off taking pain medication that you need, but monitor your use and your mental state and discuss any concerns you have with your doctor.

If you or someone you know is addicted to any kind of drug, please seek help and advice.  If you or someone you know is in immediate danger, ring the emergency services.

Part one: Opioid addiction and chronic pain: Statistics

3 thoughts on “Opioid addiction and chronic pain: Long term effects”

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