Tramadol: characteristics and side effects of this pain reliever.

This drug is an opioid-type analgesic. Let's see what is its effect on the human body.

Many people suffer pain in their daily life, either due to an illness, a psychogenic cause, poor posture, or other causes. When the pain is intense and does not subside with other types of drugs, tramadol, an opioid analgesic drug, is usually prescribed (it must always be prescribed by a physician).

In this article we will see what are the properties and the most relevant characteristics of tramadolas well as its composition, format, indications, contraindications, mechanism of action and possible adverse effects.

Tramadol: what is it and what is it used for?

Tramadol is an opioid analgesic drug that is widely prescribed in Primary Care and Pain Units, especially when ibuprofen, paracetamol, nolotil or other pain medications are insufficient.

This drug has multiple trade namesas it has more than 70 different presentations. Some of these names are: Tioner (Gebro Farma), Ceparidin (Arafarma), Adolonta (Grünenthal), Zytram (Mundipharma), Gelpar, Dolotradol (Ferrer), Tradonal (Meda Pharma) ....

For their part, let us remember that opioids are a group of analgesic drugs (i.e. they relieve pain), which act by interacting with the opioid receptors of the cells.

Thus, tramadol relieves pain by having a pain-relieving effect on pain perception.It does so by acting on nerve cells in the brain and spinal cord. Its action is produced on the speed of transmission of the pain signal, as well as on its intensity, which results in a lower perception of pain in the patient.

Its effects last between 6 and 8 hours (depending on its concentration and speed of release). If we compare it with another opioid, such as morphine, the behavior of tramadol is quite atypical.

Composition and format of this drug.

The active ingredient of any drug is that essential substance of that drug, necessary for it to produce its therapeutic effects. In other words, it allows it to exert the pharmacological action for which it was designed. In the case of tramadol, its active ingredient is tramadol hydrochloride.

On the other hand, tramadol is available in different formats: in capsules, injectable, in drops, in effervescent tablets.... and their concentrations also vary; 50, 100, 150, 200 mg....

Generally, when their concentration is high, their release is prolonged (also called retarded). (also called retard); this means that its effect is longer in time. Tramadol extended release is especially indicated to control a type of intense, continuous and persistent pain.

This format is usually taken every 12 hours (always under medical supervision), until the pain decreases.

Properties and characteristics as an analgesic

Let's get to know the most outstanding properties of tramadol, clarifying at all times pharmacological concepts that may generate doubts.

First of all, how does tramadol act once ingested? If it is administered orally (in tablet or pill form), its absorption exceeds 40% of the dose. This is true even if other drugs are taken at the same time. On the other hand, the bioavailability of tramadol is 20%. It should be recalled that the bioavailability of a drug refers to the percentage of the administered dose of the drug that reaches the bloodstream..

On the other hand, as a noteworthy characteristic of tramadol, it has a high muscle affinity, which means that it binds up to 20% to plasma proteins. Its concentration in plasma is maximum when the drug has been administered for 3 hours.

On the other hand, its shelf life ranges from 6 to 8 hours. (the shelf life of a drug is the time that the drug maintains its potency at 90% or more, without its chemical and physical properties being modified).

As for its half-life, this is approximately 6 hours (the half-life of a drug is the time it takes for it to lose half of its pharmacological activity).

Metabolism and elimination

At the metabolic level, tramadol is metabolized in the liver. This process occurs thanks to two isoenzymes (a type of enzyme): CYP3A4 and CYP2D6.

As for its elimination, both tramadol and its metabolites are eliminated almost entirely (up to 90%) by the renal route (kidneys).

Pharmacodynamics

How does tramadol act in our body? What is its mechanism of action? It is a non-selective pure agonist substance, which acts on three types of opioid receptors: µ, δ, δ and δ2.These are: µ, δ (delta) and κ (kappa). Its greatest affinity is for the µ receptors.

This is its main mechanism of action, although it also has other mechanisms that explain its analgesic effect, namely inhibition of noradrenaline reuptake and potentiation of serotonin release..

These two neurotransmitters (noradrenaline [NA] and serotonin [SA]) are closely related to mood (specifically, their deficit is associated with depressive states).

Indications

What is tramadol indicated for? Mainly for the treatment of pain, when the pain is of moderate to severe intensity.

Occasionally it is also used to treat low back pain.. Low back pain involves pain located in the lower back; its origin is generally related to alterations in the musculoskeletal structure of the spine.

It is worth mentioning, in this section, that tramadol does not have Anti-Inflammatory effects, as, for example, other drugs such as ibuprofen would have. This means that it does not prevent or reduce tissue inflammation, so it should not be used for this purpose.

Contraindications

Tramadol, like any other drug, presents a series of contraindications; this means that people with any of these characteristics should not take tramadol in almost any case:

• People with hypersensitivity to it.
• People who have been intoxicated (acutely) with alcohol, hypnotics, opioids, psychotropics, analgesics.
• People who are being treated with MAO inhibitors (MAOIs; a type of antidepressants).
• People with epilepsy not controlled by any treatment.
• People treated for morphine withdrawal syndrome (morphine withdrawal).
• People under 12 years of age.
• People with renal or hepatic insufficiency (in this case, its use is allowed, although under medical supervision).

Breastfeeding

In women, in the case of breastfeeding, it is known that approximately 0.1% of the dose of tramadol is secreted into the milk, so that it is recommended not to administer tramadol during this period..

If a single dose of tramadol is administered, it is not necessary to interrupt lactation (although the physician should always be consulted). On the other hand, if it is administered repeatedly and/or for several days (more than 2/3 days), lactation should be interrupted.

Side effects

Like all drugs, tramadol also has side effects. The most frequent, in this case, are: vomiting, dizziness, nausea, drowsiness, dry mouth, headache, sweating, constipation, fatigue and confusion..

Bibliographic references:

Hollingshead, J., Dühmke, R.M. & Cornblath, D.R. (2006). Tramadol for neuropathic pain. Scott, L.J. & Perry, C.M. (2000). Tramadol. Drugs, 60: 139-176. Stahl, S.M. (2002). Essential psychopharmacology. Neuroscientific bases and clinical applications. Barcelona: Ariel. Vademecum. (2018). Tramadol.