CLASSES OF DRUGS
An analgesic (alges/o = sensitivity to pain) is a drug that lessens pain. Mild analgesics
relieve mild to moderate pain, such as myalgias, headaches, and toothaches. More potent
analgesics are narcotics or opioids, which are derived from opium. These drugs may induce
stupor (a condition of near-unconsciousness and reduced mental and physical activity).
They are used only to relieve severe pain because they may produce dependence.
Some non-narcotic analgesics reduce fever, pain, and inflammation and are used for
joint disorders (osteoarthritis and rheumatoid arthritis), painful menstruation, and acute
pain due to minor injuries or infection. These agents are not steroid hormones (such as
cortisone) and are known as nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs act
on tissues to inhibit prostaglandins (hormone-like substances that sensitize peripheral
pain receptors). A newer class of stronger NSAIDs is the COX-2 (cyclooxygenase-2)
inhibitors. These agents block prostaglandin production. They relieve pain and inflammation
as do traditional NSAIDs but produce fewer gastrointestinal side effects than with NSAIDs.
However, they may increase the risk of clot formation and heart attacks (myocardial
infarctions). Examples of COX-2 inhibitors are Celebrex and Bextra.