How Do Painkillers Work?

Pain is an unpleasant sensation arising from a damaging stimulus. Its function is to provide the body with an early warning system so as to prevent injury and maintain optimum functioning. There are two major types of pain: fast pain and slow pain. Fast pain can be felt as fast as 0.1 seconds after the painful stimulus while slow pain begins after 1 second or longer and persists in intensity. Slow pain is usually associated with tissue destruction. Do you know how painkillers work?

Causes of pain

The pain receptors in the skin and other tissues are free nerve endings and can be stimulated by mechanical, thermal and chemical pain stimuli. In general, fast pain is elicited by the mechanical and thermal types of stimuli, whereas slow pain can be elicited by all three types. Examples of chemicals produced by the body that causes pain include bradykinin, serotonin, histamine, lactic acid, acetylcholine and prostaglandins.

Painkillers

Painkillers are drugs used for pain relief. In terms of their action, they can be broadly classified into 2 major groups – non-narcotic analgesics and narcotic analgesics.

Non-narcotic analgesics

These are analgesics that do not have CNS effects, like:

·         NSAIDS (Non-steroidal anti-inflammatory drugs) - the principal action of these painkillers is the inhibition of prostaglandin production.

·         Paracetamol is a weak cyclooxygenase inhibitor in peripheral tissues.

Narcotic analgesics

Narcotic analgesics are more effective compared to non-narcotic analgesics but they also tend to have central nervous system effects. They are of two types, namely: Natural and Synthetic.

Ultimately, type of used painkiller should depend on the type of pain felt.