Tramadol intoxication: a review of 114 cases

Abstract

<jats:p> Tramadol as a centrally acting analgesic is extensively used in the management of moderate to severe pain. It slightly affects opioid receptors and inhibits the reuptake of norepinephrin and serotonin in the CNS. There are reports about toxicity and abuse of tramadol. The objective of the present study was to evaluate epidemiology of intentional tramadol intoxications. All poisoning cases that admitted to Loghman-Hakim Hospital Poison Center from April to May 2007 were studied. A total of 114 cases (82 men and 32 women) of intentional tramadol intoxications with the median age of 23.66 ± 6.87 years (range 16–54 years) were identified. Other illicit drugs were found to be used in combination with tramadol in some of the cases, which among them benzodiazepines were the most common. Tramadol overdose has been one of the most frequent causes of drug poisoning in the country in the recent years, especially in male young adults with history of substance abuse and mental disorders. Nausea, vomiting, Central Nervous System (CNS) depression, tachycardia, and seizure are the most common findings in this kind of poisoning. Cardiopulmonary arrest was found as the cause of death in cases who had ingested more than 5000 mg tramadol. </jats:p>

Factors Related to Seizure in Tramadol Poisoning and Its Blood Concentration

“…Tramadol was authorized by the Iran Drug Selecting Committee in 2002 as an analgesic. During this period, it has been abused especially by the younger population [5].…”

“…Tramadol binds weakly to the μ-opioid receptor and also inhibits reuptake of monoamines such as serotonin and norepinephrine [2][3][4][5]. Most of the analgesic effect of tramadol may be secondary to non-opioid properties, via the central monoaminergic pathways.…”

“…In recent years, tramadol overdose has become one of the most common causes of poisoning admissions to emergency departments in this country [5,[8][9][10]]. An increased rate of seizure due to tramadol poisoning has also been observed.…”

“…An increased rate of seizure due to tramadol poisoning has also been observed. It is reported that 15% to 35% of patients with tramadol overdose experience seizure [5,11]. The exact mechanism of tramadol in induction of seizure remains to be elucidated yet.…”

“…The relation between serum concentrations and analgesia varies between individuals [1,5]. It is estimated that serum concentrations of 100 to 300 ng/mL are needed for analgesia [3][4][5]19].…”