Opioids are a class of drugs that are used to relieve pain. They work by binding to specific receptors in the brain and spinal cord, known as opioid receptors, which are involved in the perception of pain. While opioids can be effective in relieving pain they should be used with extreme caution due to the risk of addiction.
How Opioids Work
Opioids work by binding to specific receptors in the brain and spinal cord, known as mu, delta, and kappa opioid receptors. This binding changes the way the brain and body perceive pain, and also triggers the release of other neurotransmitters, such as dopamine, which can create a sense of euphoria or well-being.
Examples of Opioids
Examples of opioids include:
- Codeine
- Oxycodone (OxyContin)
- Hydrocodone (Vicodin)
- Morphine
- Fentanyl
- Tramadol
Opioids are generally considered a last resort option for the treatment of back pain, as they carry a high risk of addiction and overdose. They are usually prescribed for severe pain, such as that caused by a serious injury or surgery, and are usually only used for a short period of time due to the risk of addiction and other side effects.
Different Classes of Opioids
There are several classes of opioids, each with their own unique properties and uses.
- Natural opioids: These include morphine, which is derived from the opium poppy, and codeine, which is found in small amounts in opium and is also produced synthetically. These drugs have been used for centuries to relieve pain.
- Semi-synthetic opioids: These include drugs like oxycodone, hydrocodone, and hydromorphone, which are derived from natural opioids but are modified chemically in a laboratory.
- Fully synthetic opioids: These include drugs like fentanyl and methadone, which are entirely made in a laboratory. They are used for the same indications as semi-synthetic opioids but are more potent.
Duration of Action
The duration of action for different types of opioids can vary depending on the specific drug and the way it is administered. The duration of action refers to the amount of time that a drug remains active in the body after it is taken.
Here are some examples of the duration of action for commonly used opioids:
- Oxycodone: 4-6 hours (oral)
- Hydrocodone: 4-6 hours (oral)
- Codeine: 3-4 hours (oral)
- Tramadol: 4-6 hours (oral)
- Morphine: 4-6 hours (oral), 2-4 hours (intravenous or intramuscular)
- Fentanyl: 1-2 hours (intravenous or intranasal), 72 hours (transdermal patch)
- Methadone: 24-36 hours
Side Effects of Opioids
Some of the side effects of opioids include:
- Drowsiness and sedation
- Nausea and vomiting
- Constipation
- Dizziness and confusion
- Itchiness
- Respiratory depression
- Dependence and addiction
Long-term use of opioids can also cause:
- Tolerance: which means that the patient may need higher and higher doses to achieve the same pain-relieving effect.
- Hyperalgesia: which is a phenomenon where the patient becomes more sensitive to pain rather than less.
It’s important to note that opioids are highly addictive, and the risk of addiction and overdose increases with prolonged use. In the recent years, due to the opioid epidemic, the medical community is more cautious in prescribing opioids.
Who should avoid taking opioids?
Opioids are powerful drugs that can have serious side effects and should be used with caution. There are certain individuals who should avoid taking opioids or use them with extra precautions. Some examples include:
- History of drug or alcohol abuse: Opioids can be addictive and people with a history of substance abuse may be at a higher risk of becoming addicted to opioids.
- Respiratory problems: Opioids can slow breathing and may be dangerous for people with pre-existing respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD).
- Pregnant or breastfeeding women: Opioids can cross the placenta and reach the fetus, so pregnant women should only use opioids under the close supervision of a healthcare professional. Breastfeeding women should also be careful when using opioids as they can pass into the breast milk.
- Elderly people: Opioids can cause confusion and dizziness, which may be more likely to occur in older adults. They may also be more likely to experience side effects such as constipation, drowsiness and may have a higher risk of falls.
It’s important to keep in mind that the use of opioids, particularly for long-term use, has significant risks. The use of opioids should be under the close supervision of a healthcare professional, and only as part of a comprehensive treatment plan that includes non-pharmacological approaches such as physical therapy, exercise, and counseling.
