Pain
Pain is an unpleasant sensation that can disturb a patients comfort, thought sleep, or normal daily activity. It’s symptomatic of an underlying disease process and this is where we run into problems. Very often the health providers treat the symptom of pain without knowing the cause of pain. When that happens, the symptoms simply continue.
So what does the provider have to do when the drug doesn’t work? Increase the dose, increase the dose, increase the dose until the maximum limit. Then what’s happened? The patient is addicted. This is a major problem in health care. We are getting patients addicted.
A true legitimate use for narcotic analgesics are due to acute pain like trauma and procedures. Terminal patients are another very obvious reason to utilize analgesics.
We also consider pain as a vital sign. When you are evaluating your patients, you are also evaluating their pain score. You basically have to ask them a subjective question: From a score of 1 to 10, what is your pain at? You will always ask that question to a patient before you administer the pain medication because you have to chart that information. Then in 1-2 hours you must ask them again to reassess them to see if the medication is working, regardless if it’s a narcotic or not, such as acetaminophen.
If they come back with an answer that their pain is the same as before, you could deduce that it’s not working. But you also have to assess whether the patient is a drug-seeker. If the pain isn’t resolving, then we need to reevaluate because the patient shouldn’t be suffering.
Mechanism of Action
Endorphins: In our brain we have endorphin receptors and our body produces an endorphin chemical that activates those receptors. These are natural analgesics.
This is why if you work in a post operative unit and two similar patients had the same procedure by the same doctor, it is feasible that one of them might not ask for pain meds because they have a higher natural amount of endorphins.
The mechanism of action for these narcotics are that they stimulate endorphin receptors. By stimulating this receptor, it blocks the perception of pain. Remember again, that pain is a symptom. A message is being sent by the body to the brain that there is this pain. The narcotic is blocking, within the CNS, the signal that’s being sent to the brain so you don’t perceive this pain as severe as it is. So it’s blocking perception and not treating the cause of pain.
Therapeutic Uses
So when do we use narcotic opiates?
Analgesia: We use it as a analgesic for moderate to severe pain. We wouldn’t use a narcotic analgesic for mild pain.
Antitussive use meaning it blocks the cough reflex, which is also found in the brain. It blocks that feeling and sensation that you want to cough. If you have a productive cough due to a cold/flu, you don’t want to stop that cough because you want to get that mucus out and breathe easier. Why would you want to stop a person from coughing? If you have a dry, chronic cough that’s not productive and irritating a person, that’s a reason to do it. Another reason to do it is if the person can’t get any rest because they’re coughing all night.
Antidiarrheal: Narcotics slow down the intestinal motility. Normally you could expect constipation from this but if one has diarrhea, this is a good thing. There’s an exception to this however: You wouldn’t use a narcotic if someone has infectious diarrhea because the diarrhea is caused by bacteria producing toxins and this would cause the bacteria to stay there even though it’s treating the symptom of the diarrhea.
Pharmacology of the stimulation of the endorphin receptors
In the CNS
- Analgesia without the loss of consciousness as long as they don’t take toxic levels.
- Drowsiness: sleepiness.
- Behavioral changes such as euphoric, wonderful feelings which is a reason why they may abuse.
- Dysphoria: In a subset of individuals, instead of a euphoric effect, they may get a dysphoric effect and they may feel dirty and hate the feeling and never want the drug again. Sometimes it’s class specific or it’s overall with all narcotics.
- Depress cough reflex.
- Nauseant and Emetic: They do make people nauseous and make them want to vomit, especially when you inject narcotics in a hospital setting. So you give them another drug, an antinauseant. In general, after 3 days a person won’t feel nausea from it and builds a tolerance to it.
Toxic effects
If the blood levels get too high, one of the biggest concerns you have is respiratory depression where the patient is not breathing.
You may also see miosis (the pupil of the eye is constricted). If you take them into a dark room and shine a flashlight into their eye, the pupil should constrict, then when you turn the light off the pupil should dilate. If it doesn’t dilate, that’s a good sign that narcotics are involved, but it doesn’t tell you what kind of narcotics were involved.
Head injury: Head injury and narcotics are not a good combination because narcotics decrease respiratory drive and head injuries can decrease respiratory drive. In the case of someone in a car accident, for example, they wouldn’t be given this combination.
Effects of Narcotics In General
Narcotics will decrease peristalsis, slowing down the stomach and intestinal tract, so the patient may complain of constipation, or it may fix their diarrhea which is great unless they have a bacterial infection.
Narcotics will increase biliary pressure. One of the worst pains your patient may complain about is when your patient has gall stones: bile has precipitated in the biliary tree and a stone is blocking the biliary tree, causing a pressure increase in the biliary tree and the patient will complain of the most severe form of pain. If you give a narcotic to a patient with gall stones, you can’t give them our most potent narcotics because it will only create more pressure and pain.
Uterus: When a person is in labor and given a narcotic, the uterus muscle relaxes more which is good for the pain but there may not be enough power to push and the labor may stop. It may stop to the point of the patient needing a C-section. So in the case of labor, we’re not going to use our most powerful narcotics for pain, so we would use a less potent narcotic.
