How analgesic medications are classified

Analgesic drugs are one of the most commonly used types of drugs in Spain. Etymologically, the word analgesic comes from the Greek, whose meaning is lack of pain.

Therefore, we can say that an analgesic drug its usefulness to the ability to reduce the sensation of pain, which has by definition the unpleasant sensory and emotional experience associated with a real, potential or described injury in terms of said damage.

Before going into detail with the different analgesic drugs that exist today and their classification, apart from knowing the definition of pain, it is important to understand some other aspects of this term for to be able to understand more easily the importance of analgesic medicines.

What are you doing with the pain?

As already explained before, pain is an unpleasant sensory and emotional experience. We say that it is emotional and not only sensory because the pain can also be experienced without having any apparent injury.

In addition, it is important to know that pain is a subjective experience of great complexity.

It has a nocioceptive component responsible for the transmission of stimuli to the central nervous system. These stimuli allow us to defend ourselves from dangerous situations for the organism. In short, pain has two components:

• Sensory component: equivalent to the nociception or stimulation of the nerve pathways that lead to painful stimuli and that is due to the stimulation of the sensory endings.
• Emotional component: it is equivalent to the patient's individual experience of the nociceptive stimulus. It is usually the most important component, especially in cases in which the pain is chronic.

Since chronic pain is mentioned, too It is important to know that there are two types of pain according to the duration of itAcute pain (usually disappears with the healing of the process that caused it) and chronic pain (persists beyond healing). Depending on the type of pain, an analgesic or other medication will be administered.

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Characteristics of analgesic drugs

This type of medication they are usually administered orally, so this route is the path of choice. In spite of this, they also accept topical administration in the form of patches for chronic pain since they are forms of sustained release.

On the other hand, there are effervescent and liquid forms. Both give rise to adequate plasma concentrations more quickly than solid forms. In the case in which the oral route is impossible or that an immediate effect is needed, they can be administered parenterally.

Two other forms of administration are the rectal route and the topical one in ointments. Regarding the first, has a more inaccurate absorption compared to other routes.

On the other hand, analgesics administered topically have limited efficacy, since depend on the correct performance of the massage at the time of administering the ointment.

Classification of analgesic medications

We can make a general classification of analgesics by grouping them in:

• Primary.
• Secondary
• Coadjuvants

Primary analgesics

This type of drugs have the main pharmacological effect of relieving pain. They are useful for many types of pain and among these medicines we can find, in turn, three different types:

1. Pure analgesics-antipyretics: as can be the example of paracetamol.
2. NSAIDs or non-steroidal anti-inflammatories: besides analgesics they are anti-inflammatory. This group includes ibuprofen and acetylsalicylic acid.
3. Opioids: there are also different nature (pure, partial, mixed). An example can be methadone.

On the other hand, it is important to keep in mind that these drugs can cause adverse effects in our body. Nausea, vomiting, constipation and sedation are frequent, among others.

Secondary analgesics

Secondary analgesics have other indicationsHowever, they can also decrease some type of specific pain. As in the previous group, in this there are also several types.

We can find antidepressants such as amitriptyline or chlorimipramine, antiepileptics, corticosteroids, vasodilators and vasoconstrictors, muscle relaxants and local anesthetics.

Discover: Methadone: what it is and how it acts

Analgesics adjuvants

Regarding this group, mention that they are drugs that are administered at the same time as primary and secondary analgesic drugs in order to enhance its effects or to counteract some of the side effects thereof.

This group covers psychoactive drugs such as neuroleptics, anxiolytics and amphetamines, as well as corticosteroids and antiemetics.