Over-the-counter pain medications have become a regular part of our lives. Few people think twice about popping a pill to tie the pain of a head or strained muscle. Many take medication while recovering from a severe muscle, ligament, tendon or bone injury. Non-steroidal anti-inflammatory drugs (NSAIDs), both over-the-counter and prescribed, are one of the most common and accepted forms of medication used to relieve musculoskeletal pain and inflammation. Examples of this type of drug are aspirin, ibuprofen and naproxen.
Awareness of the dangers of prolonged NSAID use has increased in recent years, but the potential risks of more short-term use have not received much attention. NSAIDs may lend pain by reducing inflammation, but this same action may slow the healing process of a variety of injuries.
Inflammation and NSAID Action
Inflammation is part of the immune system's response to injury. When an injury or threat is detected by the immune system, it sends a rush of inflammatory fluids and white blood cells to the area to: 1) isolate the threat by blocking the injured area off from the rest of the body and 2) facilitating healing and tissue regeneration.
While inflammation serves a necessary purpose, it is painful and unpleasant. Sometimes, the immune system overreacts and causes an excess of inflammation in an injured area. If the infection is not controlled through other means, then tissue damage can occur. Controlling pollution is a difficult science; While NSAIDs can help to regulate over-infection, they can also reduce an already-weak response.
NSAIDs indirectly interfere with the production of inflammation in the body. The inflammatory response is caused in part by a substance called prostaglandin. Prostaglandins are produced by the enzymes Cox-1 and Cox-2, which NSAIDs block.
Inhibition of Healing
Reducing the amount of prostaglandins in the body has other effects besides the reduction of inflammation. These substances also play in a role in bone reformation. This means that taking NSAIDs to treat pain from a bone fraction can significantly delay healing and lead to failed fusion or setting of the bone.
NSAIDS have also shown to interfere with the healing process of soft tissues, especially ligaments and tendons. Ligaments connect bones together, and tendons connect muscles to bones. Both of these types of connective tissue receive very little blood supply; these accounts for the slow healing of tendon and ligament injuries. Fresh blood is needed to deliver healing substances to injured tissues in order to facilitate regrowth. Tendons and ligaments are not capable of significant inflammation due to their limited blood supply. When NSAIDs are taken to further reduce infection, the healing process is delayed if not destroyed.
Normally, infection is followed by fibroblast proliferation to injured areas. Fibroblast cells synthesize collagen, a key component of ligaments and tendons. If one phase of the natural healing process is halted, the next phase will not occur. This means that reducing inflammation can cause fibroblast deficiency.
In 1993, Dr. Louis Almekinders studied the recovery progress of patients with tendon overuse injuries. One group was treated with NSAIDs, one with a combination of NSAIDs and exercise, one with only exercise, and one went without treatment. The group that took NSAIDs alone had no fibroblast synthesis. The group treated with exercise and NSAIDs showed little synthesis, and the group treated with exercise alone was the only group that showed increased fibroblast synthesis compared to the control group. An abstract of the study can be viewed at http://www.ncbi.nlm.nih.gov/pubmed/7726341 .
For normal, minor muscle strains, NSAIDs can treat pain without disabling the healing process, which generally takes 2-3 days. This is because muscles receive a large amount of blood and tend to over-inflame, leading to unnecessary pain. Any prolonged injury, especially to ligaments, tendons or bones, should not be treated early on with NSAIDs. The disadvantages of delayed healing outweigh the advantage of pain relief.
It is important to be informed about your treatment. If you suffer a musculoskeletal injury that takes more than a week to heal, NSAIDs should not be part of your early recovery as they interfere with your body's healing abilities.