Learn About Opioid Medications?

The term ‘opioid’ is derived from opium, which is an extract from the poppy seed plant.  These agents have been available for centuries to relieve pain. Opioids work by binding to opioid receptors, which are found predominantly in the central nervous system (brain) and the gastrointestinal tract.

The following is a comprehensive listing of the broad classes of narcotics:

  • Natural Opioids:  alkaloids contained in the resin of the opium poppy
    • Morphine
    • Codeine
    • Thebaine – most poisonous and is not used for medical purposes, however is converted to semi-synthetic opioids.
    • Oripavine – very useful medically for its antispasmodic effects.
  • Semi-synthetic Opioids: from the natural opioids
  • Fully-synthetic Opioids:
    • Fentanyl
    • Pethidine
    • Methadone
    • Propoxyphene
  • Endogenous Opioid Peptides: produced naturally in the body (endorphins, enkephalins, dynorphins, and endomorphins).

All of the opioids have similar clinical effects that vary from one another in potency, speed on onset, and duration of action.  Both short-acting and long-acting formulations are available, as some opioids are used around-the-clock while others are used as needed for breakthrough pain.

Frequently Oxydone and Hydrocodone are combined with Acetaminophen (Tylenol) to produce a combination medicaltion, Vicodin and Percocet, respectively.

One common mistake when treating chronic pain with opioid medications is only using the short acting types of medication (Percocet, intravenous Morphine, Vicodin,).  While these medications are useful for acute pain, the short acting nature of these medications encourages overuse and the development of tolerance. Long-acting opioids may have fewer cognitive side effects and better control of chronic pain.

Long-acting opioids used in medical treatment

Active ingredient Brand name Recommended usual dosing frequency per day
Morphine Avinza 1
Morphine Kadian 1–2
Morphine MS-Contin, generic 1–3
Methadone Dolophine, generic 2–3
Fentanyl Duragesic, generic Every 72 hours
Levorphanol Levo-Dromoran 3–4
Codeine Codeine Contin 2
Dihydrocodeine DHC Continus 2
Oxymorphone Opana ER 2

Tramadol (Ultram) is an atypical opioid that is a centrally acting analgesic, used for treating moderate to severe pain. It is a synthetic agent and analogue of codeine, and appears to have actions on the GABAergic, noradrenergic and serotonergic systems. Unlike most other opioids, Tramadol is not considered a controlled substance in many countries (including the U.S).  An extended-release formula is available to treat moderate to severe chronic pain when treatment is needed around the clock.

Side Effects

Commonly experienced side effects may include gastrointestinal upset (nausea, constipation), lethargi/ drowsiness, hormonal effects (decreased testosterone levels, decreased libido and sex drive, irregular menses), depression, and suppression of the immune system and change in sleep patterns.   A rare, however serious complication is pulmonary edema.  Although this is more commonly seen in heroine users, it has been reported in patients taking morphine for pain control and withdrawl symptoms.

Studies show about 5-15% of chronic pain patients using narcotic pain medications develop dependence and therefore require higher doses of the medication for pain relief.  Patients who take opiates for an extended period of time will typically suffer withdrawl symptoms if abruptly stopping the medication.

Early symptoms of withdrawal include:

  • Agitation
  • Anxiety
  • Muscle aches
  • Increased tearing
  • Insomnia
  • Runny nose
  • Sweating
  • Yawning

Late symptoms of withdrawal include:

  • Abdominal cramping
  • Diarrhea
  • Dilated pupils
  • Goose bumps
  • Nausea
  • Vomiting

The Opioid Controversy

About 9% of the population is believed to misuse opiates over the course of their lifetime, including illegal drugs like heroin and prescribed pain medications such as Oxycontin.  Considerable debate exists about the use of opioids for treatment of chronic pain of non-cancer origin. Many physicians feel that opioids can play an important role in the treatment of all types of chronic pain, including non-Cancer Pain.  Others caution against the widespread use of opioids noting problems with tolerance, loss of benefit with time, and escalating usage with decreasing function in many individuals.

The use of opioids makes sense when the benefits outweigh the risks and negative side effects. Benefit is suggested when there is a significant increase in the person’s level of functioning, when there is a reduction or elimination of pain complaints, when there is a more positive hopeful attitude and when side effects are minimal or controllable.  The dilemma with the long term use of opioids is that while there is a role for opioids in chronic pain it is well known that prolonged use of opioids may result in tolerance.



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