If speaking in general terms, painkiller medications (analgesics) include any drug substances that can deliver pain relief effectively when used. In most cases these substances affect the central nervous system and decrease the intensity of pain signals transmitted to the brain or block these signals from entering the brain altogether. Thus, pain is eliminated without affecting the conscious state or providing anesthetic effects (numbing a part or the entire body and making it insensitive to any contact).

There are many drugs that deliver pain relief effects to various extents, but they are usually grouped into two distinct classes: narcotic and non-narcotic painkillers. Different sources also suggest non-steroidal anti-inflammatory drugs (NSAIDS) and other similar medications such as aspirin to painkillers because they are also known to provide pain relief effects to different degrees. Still, with these drugs the primary effect is elimination of inflammation (which can lead to pain relief in certain situations) and not the pain relief itself. That's why it's wrong to consider aspirin and any other anti-inflammatory drugs as painkillers.

Non-narcotic analgesics

Acetaminophen is regarded one of the most popular and widely available non-narcotic painkiller drugs out there available as an over-the-counter medication. Acetaminophen is very popular because of the low price and high effectiveness in cases of mild to moderate acute pain. So it has a wide range of applications where it can be used effectively. However, it requires the user to learn rules of safety when using it, because it may cause serious problems if taken in a wrong way. It may even lead to fatal outcomes if the dosage is exceeded. Taking more than 4000mg of Acetaminophen daily or consuming it over a long period of time delivers serious impact to the liver. Mixing it with alcohol will increase the impact and can even lead to liver failure? The outcomes are usually very serious and sometimes tragic so it is very important to keep the dosage low and avoid taking the drug for a long period of time. A little known fact is that more than 600 over-the-counter medications contain Acetaminophen in different amounts, so even if a person keeps the dosage low he or she may be mixing different drugs containing the substance and getting a high dosage in the end. Most commonly it is found in cold and cough medications. So make sure to study the contents of the drugs you're using if you're taking Acetaminophen for pain relief.

Narcotic analgesics

There are two main groups of narcotic painkillers known: opiates and opioids. Opiates are the older type of narcotic painkillers representing natural substances derived from opium (strong natural drug). Opioids are synthetic derivatives of opiates that are created to provide the same nerve-blocking effects but without the narcotic effects of opiates (lack of concentration, hallucinations, changed mind state). Today, opiates are rarely used in medicine because of their side effects, and different types of opioid drugs have taken their place. Some opioid drugs are stronger than others and have a limited use. However drugs like Tramadol are very popular and widespread, being used in cases of mild to severe acute and chronic pain. Like Acetaminophen, Tramadol is widely available in drugstores and there's no problem to buy Tramadol and use it for immediate pain relief.