Most patients are able to control the symptoms of osteoarthritis, by doing exercise, physical therapy or various procedures mentioned above, while some patients require medication to help alleviate the pain. Some medications need to be taken continuously every day while some are taken only when the symptoms are severe. The physician will advise the recommended type of drugs and the frequency of administration.
Most drugs used for osteoarthritis treatment will be mentioned here. However, there are many other drugs and procedures under clinical trials and studies which will not be referred to.
The pain reliever, which is considered cheap and safe and has shown to benefit the treatment of pain in osteoarthritis patients, is acetaminophen (paracetamol). Its effectiveness in pain relief is moderate, but it will not help reduce swelling and inflammation possibly experienced by osteoarthritis patients as it does in nonsteroidal anti-inflammatory drugs (NSAIDs) group. However, acetaminophen is considered cheaper and safer than nonsteroidal anti-inflammatory drugs (NSAIDs) group and should be used as first line treatment to relieve aches/pain prior to other more-expensive and more-side-effects drugs. The dose in adults with normal liver function is 1-2 tablets every 4-6 hours or about 4 grams daily.
Some patients may require narcotic drugs that possess higher efficacy in relieving the pain. The drugs in this group include tramadol, codeine which although are more active in killing pain but are not active in reducing inflammation. These drugs may also cause nausea, vomiting, constipation, and especially drug addiction.
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)
NSAIDs (abbreviated from Nonsteroidal Anti-Inflammatory Drugs) help reduce the ache/pain, stiffness, swelling, inflammation of the joint. This group of medication includes a wide variety of drugs such as ibuprofen, naproxen, diclofenac (Voltaren®), etc. The drugs in this group are active in reducing production of prostaglandin which is the substance that causes inflammation and ache/pain. However, prostaglandin can also be found in the stomach and kidney with its role of supporting the functions of said organs. Therefore the main side effects of drug administration in this group are the developments of stomach inflammation and ulcers, and impaired renal function. These drugs should not be used in patients with a medical history of stomach ulcers, especially the patients with untreated stomach or intestinal bleeding. All drugs in nonsteroidal anti-inflammatory drugs (NSAIDs) group as well as cyclooxygenase-2 (COX-2) inhibitors (see below) are prohibited in patients with renal problems as they can cause renal failure. When taking nonsteroidal anti-inflammatory drugs (NSAIDs), patients with a history of stomach inflammation or having abdominal pain will usually be combinedly prescribed with antacids, or drugs in acetaminophen or tramadol group, or nonacetylated drugs (such as salsalate) which are considered safer for the stomach and renal system.
The new nonsteroidal anti-inflammatory drugs (NSAIDs) called cyclooxygenase-2 (COX-2) inhibitors such as celecoxib (Celebrex®), etoricoxib (Arcoxia®), etc. exert their actions by reducing prostaglandins at the inflamed site without reducing prostaglandins in the stomach. Therefore, they are quite safe for patients with a history of ulcerative stomach inflammation but still affect the renal functional impairment in patients with renal dysfunction as same as other nonsteroidal anti-inflammatory drugs (NSAIDs). So they should not be used to treat patients with renal dysfunction.
Cyclooxygenase-2 (COX-2) inhibitors are quite expensive, however they are convenient with only once- or twice-daily dosing. The important thing that has to be mentioned is the suggestion not to use two nonsteroidal anti-inflammatory drugs (NSAIDs) or nonsteroidal anti-inflammatory drugs (NSAIDs) plus cyclooxygenase-2 (COX-2) inhibitors together as they have similar mechanism of action. Combined use of two drugs not only is useless and a waste of money, but also increases more side effects.
Steroid injection into joint
Steroids are anti-inflammatory drugs which can be injected directly into an affected joint to reduce inflammation and ache/pain in patients with osteoarthritis. Steroid injection into joints will usually be performed by an orthopedist or orthopedic surgeon no more than 3-4 times per year as frequent steroid injections into the weight-bearing joints such as hip joints, knee joints or ankles may cause degeneration of cartilage as well.
Hyaluronic acid or hyaluronan injection
Hyaluronic acid or hyaluronan is a component of joint nourishing fluid. Patient with osteoarthritis will have less hyaluronic acid content than normal people due to the depletion caused by inflammation. Hyaluronic acid injection (hyaluronic or Hylan G-F 20) once a week for 2-5 weeks based on the type used will help reduce the ache/pain and remain effective for months in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) but with uncontrolled condition or in patients unable to take nonsteroidal anti-inflammatory drugs (NSAIDs). Drugs in this group are quite expensive and may cause side effects such as pain, swelling at the injection site.
Topical analgesics or analgesic sprays for joint
Topical analgesics or analgesic sprays contain nonsteroidal anti-inflammatory drugs (NSAIDs), Salicylates, skin irritants and local anesthetics which help relieve pain in the joint. Drugs in this group help reduce the pain by increasing blood circulation of the skin around the joint which in turn increases the skin temperature, resulting in the relief of pain. Skin irritants help stimulate nerve endings in the skin to cause feelings of cold or warmth which distract the pain sensation, resulting in the relief of pain.
The irritant, capsaicin, will help decrease a substance in the nerve endings called “substance P” which results in the relief of pain. Application of capsaicin in the early stage will cause a burning sensation which usually decreases and goes away with time.