Understanding the basics of pain & pain killers in Rheumatic Diseases

by Dr Arvind Chopra

Suffering from pain is universal. There are innumerable causes of pain. Despite rapid advances in medicine, we only know some of them. The relationship between mind and body is complex. We know that mind and body continuously affect each other. The environment plays a major role both in the cause and therapy of pain. And that environment includes family, social,occupational and even recreational. Using painkiller medication is only one step in the overall management. There are several other non medicinal means of reducing pain that need to be used to combat pain, more so if it recurrent or chronic . In this general article,the focus is on pain in rheumatic diseases which are the leading cause of pain and disability. Though the following descriptions apply to both short and long term use of painkillers, the emphasis is on the care required for their long term use. Rheumatic diseases are often chronic and lifelong.

Broadly speaking, painkiller drugs are classified as per their dominant effect into two groups- (1)analgesics which provide pain relief only (2)anti-inflammatory which relieve pain and inflammation. While all antiinflammatory drugs are analgesics too,analgesics are not anti-inflammatory drugs.

But before we talk of pain-killers let us ask what is inflammation? Many forms of arthritis like rheumatoid arthritis are highly inflammatory in nature. Rheumatoid arthritis is a painful arthritis that affects multiple joints and often leads to deformities. Inflammation is characterized by both pain and swelling. In addition, redness and warmth can also be appreciated if the inflammation is superficial as in the case of skin disorders. When severe, the patient may also have fever and look sick. Inflammation per se is not a specific disease entity. It is a major component in the cause, progression and complications of several diseases. In other words, it is a pathological phenomenon. Inflammation may be caused by injury, infection and altered disorderly immune system. Inflammation can strike any part of the body.

To begin with, inflammation causes initiation of all the various defense mechanisms and immune system in particular to first limit the disease and then get rid of it. Tissues respond by swelling as a result of accumulation of cells and fluid. Several chemical substances (eg histamine,bradykinin, prostaglandins, cytokines) are produced at the site of inflammation which sensitize sensory nerves causing intense pain. If there is no inflammation, infections can spread rapidly in the body causing intense damage and even death. Once the disease is cured, inflammation is not required. In healthy states, inflammation leaves behind some cellular debris and tissue damage which is rapidly cleared by the normal repair and healing processes. In some chronic diseases, inflammation does not subside and then pain and swelling become chronic.

Such chronic inflammatory diseases generally have a genetic component in their cause and inflammation is fuelled by altered and exaggerated immune responses. These inflammatory immune responses are caused by both disorderly behavior of body's own defense cells (e.g. T lymphocytes) and abnormal production of antibodies. These responses target body's own tissues. As for example, in rheumatoid arthritis it is the synovial lining in a joint that is targeted which gets inflamed leading to chronic pain,swelling and eventually deformity. On the other hand, it is the cartilage which is initially damaged in osteoarthritis primarily due to mechanical reasons of joint loading (as in case of an overweight patient) or injuryinflammation plays a minor role.Osteoarthritis is generally is a wear and tear degenerative disorder of spine and weight bearing joints (especially knees). Several structures in a joint get damaged if the arthritis is progressive. Damaged or deformed joints often remain painful even when there is no inflammation left in the joint. Movement in the joint itself causes pain though exercise is a must to maintain maximum range of motion.

Common examples of analgesics are paracetamol (popular trade names-Crocin, Pacimol), tramadol, morphine and related compounds. Several analgesics belonging to the morphine family are called opioid or narcotic analgesics and they are essentially powerful painkillers with addiction potential and significant toxicity. Opioid analgesics are reserved for very severe types of pain whether it be musculoskeletal (e.g. fracture or postoperative surgical pain) or cardiac (e.g. heart attack). Paracetamol is an effective and safe analgesic for all kinds of moderately severe pains whether they be rheumatic or headache in origin. Paracetamol also reduces fever. In case of osteoarthritis, where pain is the only disabling symptom, paracetamol is ideally suited. Paracetamol usually does not upset the stomach.

The most popular group of antiinflammatory drugs in widespread use are called non-steroidal anti-inflammatory drugs (NSAID). Common examples are aspirin/salicylates, ibuprofen (Brufen), diclofenac (Voveran), naproxen, piroxicam, nimesulide, meloxicam, celecoxib, rofecoxib, etc. NSAID in small dose can be used as analgesic only. But generally it is best to use them in inflammatory disorders when pain and swelling both are present as it is in the case of rheumatoid arthritis. Remember that NSAID can only provide symptomatic relief. NSAID are safe when used judiciously but have several toxic effects when used in high unregulated long term use, especially on the stomach and kidney. Some NSAID like celecoxib and rofecoxib are specially designed for stomach safety.

Another group of well known antiinflammatory drugs are the steroids. Steroids are the most potent anti-inflammatory drugs which can miraculously remove pain and swelling in a short period of time producing total symptomatic relief. But they do not cure the illness and only produce symptomatic relief. Unfortunately, steroids have significant toxic effects on almost on body organs and systems which limits its use. Some of the common side effects of high long term use of steroids are weight gain, hypertension,diabetes, osteoporosis and fragility fractures,easy bruisability and skin problems,proneness to infections and delayed wound healing, and all kinds of abdominal upsets. Steroids are being grossly misused and abused for quick relief. Sometimes, even doctors tend to use them as pain killers which is absolutely wrong. Also, many indigenous unregulated medicines which are often claimed to be herbal contain steroids mixed by quacks and other unscrupulous people.

However, certain amount of care and caution need to be taken when taking painkillers:-

Pain is the worst ailment that anybody can suffer from. Relief of pain is vital and often patients expect immediate relief. Remember that there are several drugs of varying potency available today to treat pain but the patient's circumstances should dictate the right choice. There is no ideal pain killer and sometimes it is a matter of luck if a particular drug in the first instance works wonder.

Doctors often choose pain killers based on their experience with any particular drug. But a certain amount of trial and error is involved. Sometimes, drugs need to be combined. Paracetamol is often combined with NSAID for better relief, but combinations as such should be discouraged. Above all, remember that so many other factors are connected with pain cause and relief. If rest can relieve pain why take a drug? All non-medicinal means should be tried under proper guidance and supervision, especially when pain becomes chronic.

Relief of pain is often a matter of comfort or a luxury when quick set solutions are demanded by people who have limited time and endless ambitions. On the other hand,there is a case of a poor man who survives on the meager fruits of his hard earned labor and cannot afford to rest because of 'pain'. All said and done, painkillers should not be allowed to worsen the offending disease or cause a new set of diseases. Above all remember, that the goal is to treat the disease and not the pain.