Pain medications are among the most commonly prescribed drugs in the world. However, not all painkillers are the same – rather, there are a variety of different medications with different effects on your body. In this article, you can find out what to look out for when taking pain medications in combination with kidney disease.
How does pain arise?
Many people know the feeling of pain. Some pain is short, some lasts a little longer, some is dull, and some can be rather electric. Few, however, understand how pain is manifested in the first place. Various organs are involved in the perception of pain in your body: your nervous system, your spinal cord and your brain. But how exactly does pain occur when you cut your finger with a knife? Let's go through that step by step:
On your fingertip, there are a number of sensors (=pain receptors) that detect and sense the cut in your skin surface. These pain receptors are located almost everywhere on your body. They are located in your bones, your tendons, your muscles and other organs. Your skin in particular has a large number of these sensors. They react to extreme temperatures, chemical stimuli such as acids, or strong compressive or tensile forces.
After the cut with the knife, these pain receptors translate the external stimulus, like a foreign language, into an electrical signal for your body. This is the only way your body can process and understand the stimulus. This electrical signal can now be transmitted via your nerves and transported to your spinal cord. This all happens in a fraction of a second. Once in the spinal cord, two important steps follow:
- Damage minimization: A stimulus sent back to the affected body part can pull the affected body part out of the danger zone in a flash. In the example of cutting your finger with a knife, you would most likely pull your hand away at the first perception of pain so that your finger is not further injured.
- Transmission to the brain: Your spinal cord transmits the electrical signal from the nerves to the brain.
An evaluation of the pain takes place in the brain and, if it the pain strong enough, it enters your consciousness. In this way, an unpleasant sensation now becomes noticeable as pain with a pressing, dull, probing or cramping quality. The brain now evaluates the pain and learns from it for the future - this is called pain memory. So the next time you pick up a knife, you'll remember to be a little more careful.
The body's own pain pharmacy & chronic pain
You don't have to rely on medication to fight pain. Depending on the severity, your body is partially able to control it all by itself. Through the release of endogenous substances such as the well-known happiness hormones (="endorphins"), your body can weaken pain or completely eliminate it for a certain time. This plays an important role especially in extreme situations, such as after accidents.
However, problems can arise when a nerve pathway is damaged. The result can be a complete loss of sensation at the corresponding part of the body or in the supplied body region.
However, a pain stimulus can also result from damage to a nerve pathway itself. This pain is also known as nerve pain or neuropathic pain, and often does not respond as well to the use of traditional pain medications. Neuropathic pain can be caused after viral infections such as shingles, injuries to nerves, and metabolic diseases such as diabetes or cancer.
Acute pain is pain that lasts less than 3 months. If the pain persists beyond this period, we speak of chronic pain. Chronic pain can often not be sufficiently treated with classic pain medications.
What are the types of pain medications?
Pain medications prevent or dampen the perception or transmission of pain in several ways. Generally speaking, pain medications can be classified into two groups:
- Non-opioid analgesics
- Opioid
For sudden, mild to moderate pain, the familiar non-opioid analgesics are often sufficient. Opioids are often used for severe or chronic pain. Sometimes non-opioid and opioid medications can be combined to enhance and optimize the mode of action. Combination and selection of the right pain medications should always be discussed with your medical team, especially if you have kidney disease. Both classes of pain medications work in different ways in your body and therefore have different side effects.
Non-opioid analgesics
The common feature of these drugs is that some have an fever-reducing and usually an anti-inflammatory effect in addition to an painkilling effect. This means that they can be prescribed or taken not only for pain, but also for fever or inflammation.
A side effect of non-opioid analgesics is mainly the risk of a noxious effect on the kidneys. This plays an important role especially in people with kidney disease. So before using these drugs, you should always talk to your medical team.
Non-opioid pain medications can also irritate the stomach and intestines and, in the worst case, even lead to the formation of ulcers in the intestines. If you are recommended to take painkillers by your medical team, it is important that you pay attention to any changes in your body. In addition, if someone who is not a nephrologist recommends or even directly prescribes these medications, be sure to check with your nephrology care team before taking them. This is because they are the experts on your kidney disease and are aware of possible effects of medications on your kidneys. If you notice any side effects, quickly inform your medical team, so that together you can find the best solution for your body.
Opioids
These are the "heavy hitters" among pain medications. They can be addictive and, as always, should only be taken as prescribed by your medical team. They are used primarily for severe pain. At the beginning of treatment, they often make you tired and can limit responsiveness and cognition.
Constipation or bowel upset with nausea may also occur. Opioids in a very high dosage can also cause life-threatening respiratory failure. A less common side effect is mild itching. Because some opioids are excreted through the kidneys, if you have kidney disease - depending on the stage - you may need to adjust the dose, which is usually done by your care team.
Special case of nerve pain (=neuropathic pain)
Nerve pain, or neuropathic pain, results from direct damage to your nerve cells and is therefore a special case and often needs to be treated differently than “conventional” pain. Two common causes of nerve pain are herpes zoster (=shingles) and diabetic nerve damage (=neuropathy). Neurological medications are often used to treat this pain, and sometimes cold therapy is used. It is best to consult with your renal team and/or neurologist to determine which treatment options are best for your case.
Pain medication for kidney disease
Since a number of pain medications are excreted through the kidneys, their dose should be adjusted in many cases if you have kidney disease or are on dialysis. But don't worry, your treating medical team is very knowledgeable in this area and will be happy to help you with any questions or uncertainties.
Another doctor (=not a nephrologist) has prescribed me a painkiller – what should I do?
If a physician who is not your nephrologist prescribes you a pain medication, you should always consult with your treating medical team. The reason is that if you have an existing limitation of kidney function, it is often necessary to adjust the dose of pain medications. Some should not be taken to spare your kidney and keep it fit. However, in some cases this is overlooked, which can lead to unwanted side effects. Ideally, you should consult your medical team once too often rather than too little and be on the safe side.
Medical Note: This article is for educational and knowledge purposes only. This article is in no way intended to recommend, evaluate or promote specific classes of medications. If you have any questions about taking medications, you should always contact your medical team.
