Authored by Edda E Guareschi*
Abstract
Poisoning by Tanax® is uncommon as a suicide method, and it is even more unusual for murder-suicides. Tanax® is a veterinary drug used for euthanasia in animals and, as such, poisoning by Tanax® is almost completely limited to veterinary workers. Its active components are embutramide, mebezonium iodide and tetracaine hydrochloride. It acts as a general and local anesthetic, and paralyses skeletal muscles by a curariform-like action. A literature review is provided with focus on embutramide and mebezonium concentrations detected in body fluids and solid organs of patients and victims. A unique case of murder-suicide by Tanax® poisoning is then detailed, leading to the medico-legal diagnosis of a complex suicide method following the murder. This case highlights the heterogeneity of information about lethal concentrations of embutramide and mebezonium in human body fluids and solid organs, the possible emergence of embutramide as a drug of abuse, and the delayed hepatotoxicity induced by dimethylformamide (DMF), contained in Tanax® as an organic solvent.
Keywords: Tanax®; Suicide; Abuse; Toxicology; Veterinary
Introduction
Tanax® is a drug used in veterinary medicine for euthanasia in animals. It is a solution of three components dissolved in a mixture of the organic solvent dimethylformamide (DMF) and water. The components of Tanax® are embutramide, mebezonium iodide and tetracaine hydrochloride. Embutramide, which is exclusively used in Tanax® [1] is a general anesthetic with a strong narcotic action: it causes deep anesthesia by paralyzing the breathing centers in the central nervous system. Mebezonium iodide has a curariformlike action, paralyzing the skeletal muscles with fast respiratory collapse. Tetracaine hydrochloride is a local anesthetic, used to avoid pain at the injection site [2].
Poisoning by Tanax® is a rare mode of suicide [3]. Murdersuicide is even less common, with only one case reported to date [4]. In addition to the effects of the three components, hepatotoxicity has been observed both in non-fatal and fatal human poisoning, and has been attributed to DMF [5,6]. The nature and use of the drugs almost completely confine self-poisoning by Tanax® to veterinary workers, who are at high risk of dying by suicide [7,8]. Literature case studies depict administration routes as oral ingestion, subcutaneous, intravenous and intracardiac injection [2] as well as analytical methods for embutramide and mebezonium detection [9]. To date, lethal concentrations in blood, urine, liver and kidney have been reported and are summarized in (Table 1) [1,3,10,11].
Here we report a unique case of murder-suicide by poisoning with Tanax®, where a veterinarian murdered his dog and himself using 50ml of Tanax®. According to published data, the concentrations of embutramide and mebenzonium in the veterinarian’s blood and urine were not lethal, and he would have survived if he had been promptly assisted and admitted into intensive hospital care.
Case History
In January 2012 the bodies of a man and his dog were found dead in a wood near Parma, in north-eastern Italy (Emilia-Romagna region). A passer-by spotted the human body from a distance, when he approached, he was surprised to discover a dog body lying next to it. The wood, a regional park of roughly 2,000 ha, has footpaths and is a popular destination for joggers, walkers and cyclists during the warmer months (Figure 1). The police, the forensic team and the recovery team easily reached the bodies on foot.
The bodies appeared close to one another and were scarcely strewn with leaf litter, the man was fully clothed, no insect colonization was observed on either body. No trauma to the bodies was evident at the scene, except a syringe with a clear liquid and a butterfly needle inserted within a vein in the man’s left ankle. The deceased man was promptly identified as a veterinary clinician, and the dog was positively identified as his. Three days before the bodies recovery, the veterinarian’s family had reported his disappearance to the local police. The prosecutors’ office decided that a criminal investigation would be conducted to determine the manner and time of death of both man and dog.
The purpose of the investigation was to ensure that the man’s cause of death was suicide, which was suspected based on the family reports about mental illness, depression and personality disorder, for which he was in the care of a psychiatrist.
Materials and Methods
At the death scene no traumatic findings were observed on either body (dog or man), except for a syringe with a butterfly needle inserted into a vein in the man’s left ankle, where the jeans trousers and the socks had been moved to expose the skin. The 60 mL syringe contained 23 mL of a clear transparent liquid. Next to the bodies some objects were recovered: a bottle of sparkling wine (70 cl, 12% alcohol) with a quarter remaining; a dog leash; a small backpack containing an empty bottle of Tanax® 50 mL; its paper box; and a 6 mL syringe containing six whole tablets and one half tablet of an unknown medication.
As agreed with the prosecutor, the forensic investigations started with the human body, and would later be extended to the dog body, if necessary. The external examination revealed a male, 30-35 years-old, of robust build (height 187 cm, weight 100 kg), with a needle puncture in the left ankle.
The autopsy showed cerebral oedema (1540g) and pulmonary bilateral oedema (1000g and 1050g), subpleural bilateral petechial hemorrhages, abundant mucus and foam in the bronchi lumen, light hypertrophy of the left ventricle (heart weight 440g), light hepatic steatosis, confirmed by histology, and surgical procedure of gastric binding, secured to the left rectus abdominis muscle. Toxicology analyses were performed on the human body biological samples by the Toxicology Section of the University of Milan, Italy, following a validated technique [12].
To read more about this article... Open access Journal of Forensic Science & Medicine
To know more about our Journals....Iris Publishers
No comments:
Post a Comment