Thiopental Sodium

Sodium thiopental, also known as Sodium Pentothal (a trademark of Abbott Laboratories, thiopental, thiopentone, or Trapanal (also a trademark), or Fatal-Plus in veterinary euthanasia contexts, is a rapid-onset short-acting barbiturate general anesthetic. It is the thiobarbiturate analog of pentobarbital, and an analog of thiobarbital. Sodium thiopental was a core medicine in the World Health Organization's List of Essential Medicines, which is a list of minimum medical needs for a basic healthcare system, but was supplanted by propofol. Despite this thiopental is still listed as an acceptable alternative to propofol, depending on local availability and cost of these agents. It was previously the first of three drugs administered during most lethal injections in the United States, but the U.S. manufacturer Hospira stopped manufacturing the drug and the EU banned the export of the drug for this purpose. Although thiopental abuse carries a dependency risk, its recreational use is rare. Sodium thiopental, also known as Sodium Pentothal (a trademark of Abbott Laboratories, thiopental, thiopentone, or Trapanal (also a trademark), or Fatal-Plus in veterinary euthanasia contexts, is a rapid-onset short-acting barbiturate general anesthetic. It is the thiobarbiturate analog of pentobarbital, and an analog of thiobarbital. Sodium thiopental was a core medicine in the World Health Organization's List of Essential Medicines, which is a list of minimum medical needs for a basic healthcare system, but was supplanted by propofol. Despite this thiopental is still listed as an acceptable alternative to propofol, depending on local availability and cost of these agents. It was previously the first of three drugs administered during most lethal injections in the United States, but the U.S. manufacturer Hospira stopped manufacturing the drug and the EU banned the export of the drug for this purpose. Although thiopental abuse carries a dependency risk, its recreational use is rare. Sodium thiopental is an ultra-short-acting barbiturate and has been used commonly in the induction phase of general anesthesia. Its use has been largely replaced with that of propofol, but retains popularity as an induction agent for rapid-sequence intubation and in obstetrics. Following intravenous injection, the drug rapidly reaches the brain and causes unconsciousness within 30–45 seconds. At one minute, the drug attains a peak concentration of about 60% of the total dose in the brain. Thereafter, the drug distributes to the rest of the body, and in about 5–10 minutes the concentration is low enough in the brain that consciousness returns. A normal dose of sodium thiopental (usually 4–6 mg/kg) given to a pregnant woman for operative delivery (caesarian section) rapidly makes her unconscious, but the baby in her uterus remains conscious. However, larger or repeated doses can depress the baby. Sodium thiopental is not used to maintain anesthesia in surgical procedures because, in infusion, it displays zero-order elimination pharmacokinetics, leading to a long period before consciousness is regained. Instead, anesthesia is usually maintained with an inhaled anesthetic (gas) agent. Inhaled anesthetics are eliminated relatively quickly, so that stopping the inhaled anesthetic will allow rapid return of consciousness. Sodium thiopental would have to be given in large amounts to maintain an anesthetic plane, and because of its 11.5- to 26-hour half-life, consciousness would take a long time to return. In veterinary medicine, sodium thiopental is used to induce anesthesia in animals. Since it is redistributed to fat, certain lean breeds of dogs such as sighthounds will have prolonged recoveries from sodium thiopental due to their lack of body fat and their lean body mass. Conversely, obese animals will have rapid recoveries, but it will be some time before it is entirely removed (metabolized) from their bodies. Sodium thiopental is always administered intravenously, as it can be fairly irritating; severe tissue necrosis and sloughing can occur if it is injected incorrectly into the tissue around a vein. Sodium thiopental decreases the cardiac stroke volume, which results in a decrease in cardiac output. The decrease in cardiac output occurs in conjunction with a decrease in systemic vascular resistance, which results in hypotension. However, in comparison with propofol, the reflex tachycardia seen during states of hypotension is relatively spared (a bradycardia is common after administration of propofol) and therefore the observed fall in blood pressure is generally less severe. In addition to anesthesia induction, sodium thiopental was historically used to induce medical comas. It has now been superseded by drugs such as propofol because their effects wear off more quickly than thiopental.Patients with brain swelling, causing elevation of intracranial pressure, either secondary to trauma or following surgery, may benefit from this drug. Sodium thiopental, and the barbiturate class of drugs, decrease neuronal activity thereby decreasing cerebral metabolic rate of oxygen consumption (CMRO2), decrease intracranial vascular response to carbon dioxide (CO2), which in turn decreases intracranial pressure. Patients with refractory elevated intracranial pressure (RICH) due to traumatic brain injury (TBI) may have improved long term outcome when barbiturate coma is added to their neurointensive care treatment. Reportedly, thiopental has been shown to be superior to pentobarbital in reducing intracranial pressure. This phenomenon is also called a reverse steal effect. In refractory status epilepticus, thiopental may be used to terminate a seizure. Sodium thiopental is used intravenously for the purposes of euthanasia. In both Belgium and the Netherlands, where active euthanasia is allowed by law, the standard protocol recommends sodium thiopental as the ideal agent to induce coma, followed by pancuronium bromide to paralyze muscles and stop breathing.