Many people suffer pain in their daily lives, whether due to illness, psychogenic cause, poor posture, or other causes. When the pain is intense and does not go away with other types of drugs, tramadol, an opioid-type analgesic drug, is usually indicated (it should always be prescribed by a doctor).

In this article we will see which are the most relevant properties and characteristics of tramadol , as 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-type 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 names , as 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)…

On the other hand, let’s remember that opioids are a group of analgesic (that is, they relieve pain) medications, which act by interacting with the opioid receptors on the cells.

Thus, tramadol relieves pain, exerting an effect of diminishing its perception ; it does so through its action on the nerve cells of the brain and spinal cord. It acts on the speed of transmission of the pain signal, as well as on its intensity, which results in less perception of the pain by the patient.

Its effects last between 6 and 8 hours (depending on its concentration and speed of release). Compared to other opioids, such as morphine, the behaviour of tramadol is quite atypical.

Composition and format of this drug

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

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

Generally, when its concentration is high, its release is prolonged (also called retard); this means that its effect is more prolonged in time. Prolonged-release tramadol is particularly suitable for controlling a type of intense, continuous and persistent pain.

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

Properties and characteristics as an analgesic

We will know the most outstanding properties of tramadol, clarifying at all times concepts of pharmacology that may generate doubts.

First of all, how does the tramadol act once it’s ingested? If it is given orally (in tablet or lozenge 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%. Remember that the bioavailability of a drug refers to the percentage of the administered dose that reaches the bloodstream .

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

On the other hand, its useful life is between 6 and 8 hours (the useful 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 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), which are: CYP3A4 and CYP2D6.

As for their elimination, both tramadol and its metabolites are eliminated almost entirely (up to 90%) through the 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 , which are: µ, δ (delta) and κ (kappa). Its highest affinity is with the µ-receptors.

This is its main mechanism of action, although it also has others that can explain its analgesic effect, which are the inhibition of noradrenaline reuptake and the enhancement of serotonin release .

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

Indications

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

Sometimes it is also used to treat low back pain . Low back pain involves pain that is located in the lower part of the back; its origin is generally related to alterations in the muscular-skeletal structure of the spine.

It should be mentioned in this section that tramadol does not have anti-inflammatory effects, as for example other drugs such as ibuprofen would. This means that it does not prevent or reduce inflammation of tissues and should therefore not be used for this purpose.

Contraindications

Tramadol, like any other drug, has a number 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, painkillers
  • People who are being treated with MAO inhibitors (MAOIs; a type of antidepressant)
  • People with epilepsy not controlled by any treatment.
  • People treated for morphine withdrawal
  • Persons 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, if they are breastfeeding, it is known that approximately 0.1% of the dose of tramadol is secreted into the milk, so it is recommended not to administer tramadol during this period .

If a single dose is given, there is no need to stop breastfeeding (although you should always consult your doctor). On the other hand, if it is administered repeatedly and/or for several days (more than 2/3 days), breastfeeding should be stopped.

Side effects

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

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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.