Tramadol: characteristics and side effects of this pain reliever

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

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

• Related article: "Nociceptors (pain receptors): definition and types"

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 in Emergency Units. Pain, especially when ibuprofen, paracetamol, nolotil, or other pain medications are insufficient.

this drug has multiple trade names, since 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 its part, let us remember that opioids are a group of analgesic drugs (this means that they relieve pain), which act by interacting with the opioid receptors of the cells.

Thus, tramadol relieves pain, exerting an effect of decreasing its perception.; it does so through its action on nerve cells in the brain and spinal cord. Its action occurs on the speed of transmission of the painful signal, as well as on its intensity, which translates into a lower perception of pain in the patient.

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

• You may be interested in: "Types of medications (according to their use and side effects)"

Composition and format of this drug

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

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

Generally, when its concentration is high, its release is prolonged (also called retard); this means that its effect lasts longer in time. Extended-release tramadol 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

We are going to know the most outstanding properties of tramadol, clarifying at all times pharmacology concepts that can raise doubts.

First of all, how does tramadol work once taken? If administered orally (in tablet or pill format) its absorption exceeds 40% of the dose. This is the case even if other medications 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 of the drug 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 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 useful life ranges between 6 and 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).

Regarding its half-life, it 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.

Regarding its elimination, both tramadol and its metabolites are practically eliminated in their entirety (up to 90%) via the kidneys (kidneys).

pharmacodynamics

How does tramadol act in our body? What is your mecanism 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 occurs with µ receptors.

This is its main mechanism of action, although it also has others, which explain its analgesic effect, and which are inhibition of norepinephrine reuptake and potentiation of serotonin release.

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

It is also sometimes used to treat low back pain.. Low back pain involves pain that is 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. 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, has a series of contraindications; this means that people with any of these characteristics, you 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 being treated with MAO inhibitors (MAOIs; a class of antidepressants).
• People with epilepsy not controlled by any treatment.
• People treated for a morphine (morphine) withdrawal syndrome.
• People under 12 years of age.
• People with kidney or liver failure (in this case, its use is allowed, although under medical supervision).

Lactation

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

If a single dose is administered, it is not necessary 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), lactation should be interrupted.

Side effects

Like any drug, 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.