The active ingredient thiopental is a hypnotic, that is, a sleeping pill that is effective for a very short time. It is also known as Trapanal or Pentothal. The substance thiopental is a sodium salt and belongs to the group of barbiturates, which have no analgesic effect. The active ingredient was developed in the early 1930s by Volwiler and Tabern. The client in this case was Abbott Laboratories.
What is thiopental?
The active ingredient thiopental is a hypnotic, i.e., a sleeping pill that is only effective for a very short time. The active ingredient thiopental is mainly used in anesthesia to induce anesthesia. The main focus is on its use in uncomplicated patients, i.e. persons without heart or lung complaints. In addition, the active ingredient thiopental is also used in intensive care medicine, where it is used in individual cases as a continuous infusion. However, it is used as a last resort to reduce intracranial pressure and end status epilepticus. Basically, thiopental is an active substance from the category of thiobarbiturates. The substance is primarily characterized by its sleep-inducing, depressant and narcotic effects. The onset of action is very rapid and lasts only for a short time. For this reason, the active ingredient is also used in anesthesia. The drug is usually injected intravenously. An overdose should be avoided in any case, as it can sometimes be fatal. In certain countries, the substance thiopental is used in executions. It is also used in some places as a so-called truth serum and for euthanasia. However, the drug is not intended for these purposes and is not approved in Germany. In the USA in particular, the drug is used to prepare people for execution by lethal injection. In Ohio, the active ingredient thiopental was used for the first time for an execution itself in 2009. For this reason, German pharmaceutical companies no longer send shipments of thiopental to the U.S. to rule out misuse in executions. Since 2011, thiopental may no longer be exported from the EU without special authorization.
Pharmacological effect
The drug thiopental has a beneficial effect on sleep and has narcotic properties. The effect is rapid and usually occurs within circa 30 seconds. After a single dose, the effect of thiopental usually lasts for about half an hour until it gradually wears off again. In principle, the active substance thiopental has a depressant effect on the circulatory, cardiac and respiratory functions. Under no circumstances should the injection be administered too quickly. The effects of the drug result from the fact that the action of the neurotransmitter GABA is enhanced. This is because, due to its agonistic action on a specific part of the GABA receptor, the active substance thiopental causes increased chloride ions to enter. As a result, the nerve cells become hyperpolarized. When thiopental is taken in higher doses, the drug blocks certain processes in the central nervous system. When the drug thiopental is administered intravenously, it binds to a large extent to plasma proteins. It is then distributed in the body, initially mainly to organs with a high blood supply. Later it reaches the central nervous system and finally the muscle and fatty tissues. Finally, it is distributed evenly between the muscles and the blood plasma. In patients who are overweight, the dose of thiopental must not be increased under any circumstances. This is because the active ingredient accumulates in fatty tissue and can cause accumulation. The half-life of thiopental is between five and six hours. In the organism, the substance is metabolized to pentobarbital. The active ingredient is predominantly broken down in the liver.
Medical use and application
The drug thiopental is used primarily in anesthesia. Due to the rapid onset of hypnotic effects, the drug is used primarily for induction of anesthesia. Particularly in uncomplicated patients, the active ingredient thiopental serves as a popular substitute for the substance propofol. In addition to the medical use of the drug, other areas of application include its use in poison syringes and truth serums. In intensive care medicine, thiopental is used to reduce intracranial pressure.
Risks and side effects
Various undesirable side effects are possible during therapy with the drug thiopental. For example, respiratory depression can occur, which in the worst case can lead to respiratory arrest. In some cases, the muscles in the respiratory tract may also cramp up while the drug is being taken. Sometimes increased histamine is released and blood pressure drops sharply. In addition, a reflex acceleration of the pulse beat is possible, which irritates the veins and increases myocardial consumption of oxygen. As a result of the injection, damage to the tissue forms in some cases, which can extend to necrosis. In this case, the affected patients suffer enormous pain and there is a risk of losing extremities. Other possible side effects caused by the active ingredient thiopental include euphoric mood, confusion, drowsiness, and nausea and vomiting. An overdose of thiopental is life-threatening, as death can result from respiratory arrest or cardiovascular collapse.
