An analgesic also known as a painkiller, is any member of the group of drugs used to relieve pain (achieve analgesia).
Analgesic drugs act in various ways on the peripheral and central nervous systems, they include paracetamol, the non–steroidal anti–inflammatory drugs (NSAID's) such as the salicylates and opioid drugs such as morphine and opium. They are distinct from anesthetics, which reversibly eliminate sensation.
The pain relief induced by analgesics occur either by blocking pain signals going to the brain or by interfering with the brain's interpretation of the signals, without producing anesthesia or loss of consciousness.
Some references include aspirin and other non–steroidal anti–inflammatory drugs (NSAID's) in analgesics as these drugs have some analgesic properties. Aspirin and NSAID's primarily have an anti–inflammatory effect, as opposed to being solely analgesic. These are of two types Non–narcotic analgesics and Narcotic analgesics.
Non–narcotic analgesics:
Acetaminophen is the most commonly used non–narcotic analgesic. Acetaminophen is a popular pain reliever because it is
both effective for mild to moderate pain relief and relatively inexpensive.
It must be emphasized though that the safety of acetaminophen is tied to proper use of the drug. If acetaminophen is not used
according to the directions on the label, serious side effects and possible fatal consequences can occur. For example,
taking more than 4000mg/day or using it long term can increase the risk of liver damage. The risk of liver damage with
acetaminophen use is also increased by ingesting alcohol.
Acetamophen can be found in combination with other active ingredients in many cold, sinus and cough medications. The cumulative
effect of acetaminophen must be considered if you are talking multiple drugs which contain acetaminophen.
Narcotic analgesics:
There are two types of narcotic analgesics. The opiates and the opioids (derivatives of opiates). Opiates are the alkaloids found
in opium (a white liquid extract of unripe seeds of the poppy plant).
Opioids are any medication which binds to opioid receptors in the central nervous system or gastrointestinal tract.
Opioids are used in medicine as strong analgesics, for relief of severe or chronic pain. Interestingly, there is no upper limit
for the dosage of opioids used to achieve pain relief, but the dose must be increased gradually to allow for the development of
tolerance to adverse effects (for example, respiratory depression).