If speaking simply, analgesics (painkillers) are any drugs that can relive pain to a considerable extent. The effect of pain relief produced by these medications affects the nervous signals transmitted to the brain either by blocking them or changing the way the brain interprets them. As a result the pain is relieved without any loss of consciousness or anesthetic effects. There are different substances delivering such effects that are usually divided into two distinct classes: non-narcotics and narcotics.

Some sources also include drugs like aspirin and non-steroidal anti-inflammatory drugs (NSAIDS) in general to painkillers due to their abilities to relief pain to various extents. However, NSAIDS have an anti-inflammatory effect as their primary function and can't be considered as analgesics.

Non-narcotic painkillers

Acetaminophen is probably the popular over-the-counter painkiller of the non-narcotic class. Acetaminophen owes its popularity to the simple fact that it's quite effective in cases of mild and moderate acute pain and is quite cheap in comparison with other painkillers. However, you should keep in mind that the safety of this drug is strictly related to its right usage (prescription and instructions are a must). If the drug is used in a wrong way it may produce harmful or even fatal side-effects. For instance, if you take more than 4000 mg of Acetaminophen a day or take it for a longer period of time it can be very harmful for your liver. You will also increase liver damage if mixing the drug with alcohol. So before you start taking the drug make sure you know the right dosage and how to use it right.

Not many of Acetaminophen users know that it's contained in over 600 over-the-counter medications, being mixed with other active substances. It is commonly found in cold and cough drugs. That's why you should be careful when using Acetaminophen with other medications that may contain it.

Narcotic painkillers

There are two distinct types of narcotic painkillers: opiates and opioids. Opiates are natural chemicals that are usually found in opium (which is a very strong drug produced from seeds of poppies). Opioids are usually substances that are derived from opiates and have the ability to bind the very same receptors in the nervous system as opiates. Doctors distinct four different sub-types of opioids, each with its distinct features:

• Natural opioid peptides (found in the body itself: endorphins, enkephalins)

• Opium alkaloids (morphine, codeine, thebaine)

• Semi-artificial opioids (heroin, hydrocodone, oxymorphone)

• Fully artificial opioids (Demerol, Tramadol, methadone)

Opioids are typically used as very strong painkillers in cases of chronic or severe pain. Opioids have an interesting feature – they rarely have an upper dosage limit in contrast to other medications. However, in order to achieve the desired effect the dosage should be increased gradually, otherwise the person will experience the negative side-effects of an opioid one has to build up tolerance for in order to have any benefits from the drug. For instance, some patients who use Tramadol hcl for chronic pain relief for longer periods of time take the drug in amounts that would be lethal for those who don't use it or have only started using it.

Opioids are very effective for relieving chronic pain associated with conditions such as arthritis. That's why many patients buy Tramadol and other opioids despite their possibly addictive nature as stated by some.