Muscles And Joints

Muscles, tendons, and ligaments can be strained or torn by violent movement. Such injury may cause inflammation, making the affected tissue swollen and painful. Joints, especially those that bear the body's weight -hips, knees, ankles, and vertebrae -are prone to wear and tear. The cartilage covering the bone ends may tear, causing pain and inflammation. Joint damage also occurs in rheumatoid arthritis, thought to be a form of autoimmune disorder. Gout, in which uric acid crystals form in some joints, may also cause inflammation, a condition known as gouty arthritis.

Other problems affecting the muscles, bones, and joints include those in which nerve control over muscle contraction is altered due to injury or a neurological disorder, or by poor nerve signals as in myasthenia gravis. The mineral composition of bone may be weakened by vitamin, mineral, or hormone deficiencies.

Non-steroidal anti-inflammatory medicaments

Medicaments in this group are used to relieve pain, stiffness, and inflammation associated with a wide variety of conditions, particularly those affecting the muscles, bones, and joints. NSAIDs are called non-steroidal to distinguish them from corticosteroid medicaments, which also have an anti-inflammatory effect.

Prostaglandins are chemicals released at the site of an injury. They are believed to be the substances responsible for producing pain and inflammation following tissue damage and in immune reactions. All the NSAIDs block the production of prostaglandins and this may be how they reduce pain and inflammation.

NSAIDs are usually effective in reducing joint pain and swelling. They are rapidly absorbed from the digestive system and most start to relieve symptoms within an hour. When used regularly for long-term treatment, they reduce stiffness and may restore or improve the function of a joint if this has been impaired. Common side effects include nausea, indigestion, and altered bowel action. But the potential of most NSAIDs to irritate the stomach is less than that of uncoated ASA.

Most NSAIDs are short-acting and need to be taken several times a day in order to provide optimal relief of pain. Some need to be taken only twice daily. Others such as piroxicam are very slowly eliminated from the body and are effective when taken once a day.

With a few exceptions, most NSAIDs are free from serious adverse effects. The main danger is that they can occasionally cause bleeding in the stomach or duodenum. They should normally be avoided by people who have suffered from peptic ulcers. The NSAIDs' side effect of bleeding is due to their antiprostaglandin action. To protect against this, misoprostol, a prostaglandin-like medication, is sometimes prescribed with the NSAID.

Most NSAIDs are not recommended during pregnancy or for nursing mothers. Caution is also advised for those with kidney or liver abnormalities or with a history of hypersensitivity to other medicaments. NSAIDs may also impair normal blood clotting and are, therefore, prescribed with caution for people with bleeding disorders or who are taking medicaments that reduce blood clotting. One of the first NSAIDs, phenylbutazone, can impair the bone marrow's ability to produce blood cells. Early signs of this include sore throat or fever, and must be reported. Phenylbutazone is usually prescribed only for ankylosing spondylitis and acute attacks of gout with regular blood tests required.

Antirheumatic medicaments

These medicaments are used in the treatment of various rheumatic disorders, the most crippling and deforming of which is rheumatoid arthritis. It is thought to be a form of autoimmune disease in which the body's mechanism for fighting infection contributes to the damage of its own joint tissue. The disease causes pain, stiffness, and swelling of the joints that over many months can lead to deformity. Flare-ups of rheumatoid arthritis also cause a generalized feeling of being unwell.

Treatments include medicaments, rest, changes in diet, immobilization of joints, and physical therapy. Rheumatoid arthritis cannot yet be cured, although in many cases it does not progress far enough to cause permanent disability. The disease may subside spontaneously.

It is not known precisely how most antirheumatic medicaments stop or slow the disease process. Some may reduce the body's immune response, which is thought to be partly responsible for the disease. When effective, such medicaments prevent damage to the cartilage and bone, thereby reducing progressive deformity and disability. The effectiveness of each medication varies depending on individual response.

These medicaments are generally slow-acting; it may be weeks or even months before benefit is noticed. Treatment with NSAIDs or ASA is usually continued. After this time, however, antirheumatic medicaments can cause a marked improvement in symptoms. Pain is reduced, joint mobility increased, and generalized symptoms of ill health fade. Side effects, which vary among medicaments, may be noticed before any beneficial effect, so patience is required. Severe adverse effects may necessitate abandoning the treatment.

Locally acting corticosteroids

The adrenal glands, one atop each of the kidneys, produce a number of important hormones. Among them are the corticosteroids, so named because they are made in the outer part (cortex) of the glands. These hormones play an important role, influencing the immune system and regulating the carbohydrate and mineral metabolism of the body. A number of medicaments that mimic the effects of natural corticosteroid hormones have been developed.

These medicaments have two main actions that are thought to account for their effectiveness. They depress the activity of the white blood cells, which are responsible for inflammation, and also block the production of chemicals called prostaglandins, which are responsible for triggering pain and inflammation. Administration by injection concentrates the effects of the corticosteroids at the site of the problem, producing maximum benefit where it is most needed with minimum side effects.

Corticosteroids usually produce dramatic relief from symptoms when they are injected into a joint. Often a single injection is sufficient to relieve pain and swelling, and to improve mobility. When used to treat muscle or tendon pain they may not always be effective because it is difficult to position the needle so that the medication reaches the right spot. In some cases repeated injections are necessary.

Because these medicaments are concentrated in the affected area, and are not dispersed in significant amounts in the body, the generalized adverse effects that may occur with corticosteroids taken by mouth are unlikely. Minor side effects such as loss of skin pigment at the injection site are uncommon. Occasionally, a temporary increase in pain (steroid flare) may occur. In such cases, local application of ice, rest, and analgesic medication may relieve the condition. Sterile injection technique is critically important.

Medicaments for gout

Gout is a disorder that arises when the blood contains increased levels of uric acid, a by-product of normal body metabolism. When its concentration in the blood is excessive, uric acid crystals may form in various parts of the body, especially in the joints of the foot (most often the big toe), the knee, and the hand, causing intense pain and inflammation known as gouty arthritis. Crystals may form as white masses, known as tophi, in soft tissue, and in the kidneys as stones. Attacks of gouty arthritis can recur, and may lead to damaged joints and deformity. Kidney stones can cause kidney damage.

An excess of uric acid can be caused either by increased production or by decreased elimination by the kidney which removes it from the body. The disorder tends to run in families and is far more common in men. The risk of attack is increased by high alcohol intake, obesity, and the consumption of certain foods (including red meat, sardines, anchovies, liver, and brains). An attack may be triggered by medicaments such as thiazide diuretics, anticancer medicaments, or excessive drinking. Changes in diet and a reduction in alcohol consumption may be an important part of treatment.

Medicaments used to treat acute gout include non-steroidal anti-inflammatory medicaments, such as indomethacin, colchicine, and, less commonly today, corticosteroids and corticotropin (ACTH), which controls the production and release of adrenal corticosteroid hormones. Others which lower the blood level of uric acid are allopurinol and the uricosuric medicaments, probenecid and sulfinpyrazone. ASA is not prescribed for pain relief because it slows the excretion of uric acid.

Allopurinol reduces the level of uric acid in the blood by interfering with the activity of xanthine oxidase, an enzyme that is involved in the production of uric acid in the body. Probenecid and sulfinpyrazone increase the rate at which uric acid is excreted by the kidneys. Colchicine may decrease inflammation (and therefore pain) by interfering with the action of white blood cells in joints where uric acid crystals deposit.

Medicaments used in the long-term treatment of gout are usually successful in preventing attacks and joint deformity. However, response may be slow. Colchicine can disturb the digestive system, causing abdominal pain, which your physician can manage.

Since they increase the output of uric acid through the kidneys, uricosuric medicaments can cause uric acid crystals to form in the kidneys. They are not, therefore, usually prescribed for those who already have kidney problems. In such cases allopurinol may be preferred. It is always important to drink plenty of fluids while taking anti-gout medicaments to prevent kidney crystals from forming. Regular blood tests to monitor levels of uric acid in the blood may be required.

Muscle-relaxant medicaments

Several medicaments are available to treat muscle spasm: the involuntary, painful contraction of a muscle or a group of muscles that can stiffen an arm or leg, or make it nearly impossible to straighten your back. There are various causes of muscle spasm. It can follow an injury, arise spontaneously, or be brought on by a disorder like osteoarthritis, the pain in the affected joint triggering abnormal tension in a nearby muscle.

Spasticity is another form of muscle tightness seen in some neurological disorders such as multiple sclerosis, stroke, or cerebral palsy. This can sometimes be helped by physical therapy but in severe cases medicaments may be used to relieve symptoms.

Muscle-relaxant medicaments work in one of two ways: the centrally acting medicaments slow down the passage of the nerve signals from the brain and spinal cord that cause muscles to contract, thus reducing excessive stimulation of muscles and unwanted muscular contraction. Dantrolene reduces the sensitivity of the muscles to nerve signals.

Medicaments taken regularly for a spastic disorder of the central nervous system usually reduce stiffness and improve mobility. They may restore the use of the arms and legs when this has been impaired by muscle spasm.

Unfortunately, most centrally acting medicaments can have a generally depressant effect on nervous activity and produce drowsiness, particularly at the beginning of treatment. Too high a dosage can excessively reduce the muscles' ability to contract and can therefore cause weakness. For this reason, the dosage must be carefully adjusted in order to find a level that controls symptoms and at the same time maintains sufficient muscular strength.

The main long-term risk associated with centrally acting muscle relaxants is that the body may become dependent on the medication for depressing the excessive nervous activity responsible for muscle spasm. If the medication is withdrawn suddenly, the stiffness may become worse than it was before medication treatment began.

Dantrolene can, in rare cases, cause serious liver damage, and for this reason those taking this medication should have their blood tested regularly to assess liver function.

Medicaments used from myasthenia gravis

Myasthenia gravis is a disorder that occurs when the immune system becomes defective and produces antibodies that disrupt the signals being transmitted between the nervous system and the muscles under voluntary control. The result is a progressive weakening of muscular response. The muscles first affected are those controlling the eyes, eyelids, face, pharynx, and larynx, with muscles in the arms and legs becoming involved as the disease progresses. The disease is often linked to a disorder of the thymus gland, the source of the destructive antibodies concerned.

Treatment of myasthenia gravis can take several forms. It may involve the removal of the thymus gland (thymectomy). Temporary relief may be obtained by clearing the blood of antibodies, a procedure known as plasmapheresis. Medicaments are available that improve muscle function, principally neostigmine and pyridostigmine. They may be used alone or together with other medicaments that depress the immune system -usually corticosteroids or azathioprine.

Normal muscle action occurs when a nerve impulse triggers a nerve ending to release a neurotransmitter, which combines with a specialized receptor on the muscle cells and causes the muscles to contract. In myasthenia gravis, the body's immune system destroys many of these receptors, so that the muscle is less responsive to nervous stimulation. Medicaments used to treat the disorder, like neostigmine, increase the amount of neurotransmitter at the nerve ending by blocking the action of an enzyme which normally breaks it down. Increased levels of the neurotransmitter permit the remaining receptors to function more efficiently.

These medicaments usually restore muscle function to a normal or near normal level particularly when the disease takes a mild form. Unfortunately, they can produce unwanted muscular activity by enhancing the transmission of nerve impulses elsewhere in the body.
Common side effects include vomiting, nausea, diarrhea, and muscle cramps in the arms, legs, and abdomen.

Muscle weakness can suddenly worsen even when it is being treated with medicaments. Should this occur, it is important not to take larger doses of the medication in an attempt to relieve the symptoms, because excessive levels can interfere with the transmission of nerve impulses to muscles, causing further weakness. The administration of other medicaments, including some antibiotics, can also markedly increase the symptoms of myasthenia gravis. If your symptoms become any worse, your physician should be consulted.

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