Tramadol is an opioid centrally acting analgesic, used to treat moderate to severe pain of various genesis in children aged 12 and more, and in adults. As an analgesic, Tramadol is used since 1997. Due to its unique action mechanism and an insignificant risk of side effects, Tramadol was rapidly conquering the international pharmaceutical market and is still one of the most prescribed analgesics.
Today, Tramadol has different release forms. To relievethe pain syndrome, Tramadol can be administered in the following ways:
- rectal (rectal suppositories);
- parenteral (solution for injection or infusion);
- oral (drops solution, extended release tablets, capsules);
The analgesic effect of Tramadol has a unique mechanism of action. The drug interacts with and activates the mu, kappa and delta receptors in the brain, thus leading to pain reduction. Studies show that Tramadol also has the ability to inhibit the neuronal serotonin and norepinephrine re-uptake in the nerve synapses. This action promotes the activation of serotonergic and noradrenergic systems.
As a result, the transmission of pain impulses is violated at the spinal level, and the emotional nature of pain changes. Each of these action mechanisms has a weak analgesic effect it self. But in combination they provide a multiple amplification of overall analgesia. Synergy of two action mechanisms of Tramadol determines its high efficacy for the treatment of moderate to severe pain.
Studies have shown that the analgesic potential of Tramadol is comparable to Codeine, and is five times lower than that of Morphine. In contrast to Morphine, Tramadol has a lower affinity for the opioid receptors, so it has a minimal narcogene potential and addiction degree.
The analgesic effect of Tramadol is achievedin an average of 30 minutes after the administration and may last up to:
- 8-12 hours (prolonged dosage forms)
- 4-6 hours (immediate-release dosage forms)
When taken orally, Tramadol absorption is about 90%. Maximum plasma concentrations are observedin 2 hours after the analgesic administration. Regardless of the administration method, Tramadol half-life in adults without clinical symptoms of hepatic or renal insufficiency is about 6h.
It should be borne in mind that:
- half-life in elderly patients (older than 75 years) can be delayed, and last 7 to 9 hours,
- in patients with renal failure - 11 to 15 hours.
Tramadol dosage should be selected individually and is adjusted according to pain severity and patient's age. The oral daily dosage of Tramadol for adults is 150 mg.
The daily dose of this pain killer may be taken at once or divided into two doses:
- Parenteral dosage for adults is 50 mg to 100 mg per day.
- The maximum daily dose of Tramadol should not exceed 400 mg.
Oral long-acting forms of Tramadol are most preferred for the long-term treatment of chronic pain. Parenteral Tramadol administration is preferable in the treatment of acute pain.
Among opioids with an average analgesic potency, Tramadol is a drug of choice that has obvious advantages:
- Firstly, the therapeutic doses of Tramadol do not cause respiratory depression, have no effect on the cardiovascular system and do not violate the motility of the gastrointestinal tract;
- Secondly, Tramadol is well tolerated and is characterized by the absence of dangerous adverse events (does not cause addiction, physical and psychological dependence).
It should be noted that along with the advantages, Tramadol is not lacking side effects. Besides, this analgesic is contraindicated in patients with epilepsy, unresponsive to medical control.
Tramadol is also contraindicated in conditions, involving severe depression of the central nervous system (e.g., alcohol intoxication or poisoning with psychoactive drugs).