Hyoscine crosses the placenta and is a United States pregnancy category C and Australian Category B1 medication, meaning a risk to the fetus cannot be ruled out. Sufficient studies in women and animals are not available to rule out harm, but existing studies have not shown increased risk. Drugs should be given only if the potential benefits justify the potential risk to the fetus. It may cause respiratory depression and/or neonatalhemorrhage when used during pregnancy. Transdermal hyoscine has been used as an adjunct to epidural anesthesia for Caesarean delivery without adverse CNS effects on the newborn. Except when used prior to Caesarean section, it should only be used during pregnancy if the benefit to the mother outweighs the potential risk to the fetus.
Hyoscine enters breast milk by secretion. Although no human studies exist to document the safety of hyoscine while nursing, the manufacturer recommends that caution be taken if hyoscine is administered to a breastfeeding woman.
The likelihood of experiencing adverse effects from hyoscine is increased in the elderly relative to younger people. This phenomenon is especially true for older people who are also on several other medications. It is recommended that hyoscine use should be avoided in this age group because of these potent anticholinergic adverse effects which have also been linked to an increased risk for dementia.
Due to interactions with metabolism of other drugs, hyoscine can cause significant unwanted side effects when taken with other medications. Specific attention should be paid to other medications in the same pharmacologic class as hyoscine, also known as anticholinergics. The following medications could potentially interact with the metabolism of hyoscine: analgesics/pain medications, ethanol, zolpidem, thiazide diuretics, buprenorphine, anticholinergic drugs such as tiotropium, etc.
One of the earlier alkaloids isolated from plant sources, hyoscine has been in use in its purified forms (such as various salts, including hydrochloride, hydrobromide, hydroiodide and sulfate), since its isolation by the German scientist Albert Ladenburg in 1880, and as various preparations from its plant-based form since antiquity and perhaps prehistoric times. Following the description of the structure and activity of hyoscine by Ladenburg, the search for synthetic analogues of and methods for total synthesis of hyoscine and/or atropine in the 1930s and 1940s resulted in the discovery of diphenhydramine, an early antihistamine and the prototype of its chemical subclass of these drugs, and pethidine, the first fully synthetic opioidanalgesic, known as Dolantin and Demerol amongst many other trade names.
In 1899, a Dr. Schneiderlin recommended the use of hyoscine and morphine for surgical anaesthesia and it started to be used sporadically for that purpose. The use of this combination in obstetric anesthesiology, was first proposed by Richard von Steinbuchel in 1902 then was picked up and further developed by Carl Gauss in Freiburg, Germany starting in 1903. The method came to be known as "Dämmerschlaf" ("twilight sleep") or the "Freiburg method". It spread rather slowly, and different clinics experimented with different dosages and ingredients; in 1915 The Canadian Medical Association Journal reported that "the method [was] really still in a state of development". It remained widely used in the US until the 1960s, when growing chemophobia and a desire for more natural childbirth led to its abandonment.
While it has been occasionally used recreationally for its hallucinogenic properties, the experiences are often unpleasant, mentally and physically. It is also physically dangerous, so repeated use is rare. In June 2008, more than 20 people were hospitalized with psychosis in Norway after ingesting counterfeit Rohypnol tablets containing hyoscine. In January 2018, 9 individuals were hospitalized in Perth, Western Australia, after reportedly ingesting hyoscine.
Historically, the various plants which produce hyoscine have been used psychoactively for spiritual reasons. When entheogenic preparations of these plants were utilized, hyoscine was considered to be the main psychoactive compound and was largely responsible for the hallucinogenic effects, particularly when the preparation was made into a topical ointment (most notably flying ointment). Hyoscine is reported to be the only active alkaloid within these plants that can effectively be absorbed through the skin to cause effects. Different recipes for these ointments were explored in European witchcraft at least as far back as the Early Modern period and included multiple ingredients to help with the transdermal absorption of hyoscine (such as animal fat) as well as other possible ingredients to counteract its noxious and dysphoric effects.
In 1910, hyoscine was detected in the remains believed to be those of Cora Crippen, wife of Dr. Hawley Harvey Crippen, and was accepted at the time as the cause of her death, since her husband was known to have bought some at the start of the year.
A travel advisory published by the United States Department of State in 2012 stated: "One common and particularly dangerous method that criminals use in order to rob a victim is through the use of drugs. The most common [in Colombia] has been hyoscine. Unofficial estimates put the number of annual hyoscine incidents in Colombia at approximately 50,000. Hyoscine can render a victim unconscious for 24 hours or more. In large doses, it can cause respiratory failure and death. It is most often administered in liquid or powder form in foods and beverages. The majority of these incidents occur in night clubs and bars, and usually men, perceived to be wealthy, are targeted by young, attractive women. It is recommended that, to avoid becoming a victim of hyoscine, a person should never accept food or beverages offered by strangers or new acquaintances, nor leave food or beverages unattended in their presence. Victims of hyoscine or other drugs should seek immediate medical attention."
Beside robberies it is also allegedly involved in express kidnappings and sexual assault. The Hospital Clínic in Barcelona introduced a protocol in 2008 to help medical workers identify cases, while Madrid hospitals adopted a similar working document in February 2015.Hospital Clínic has found little scientific evidence to support this use and relies on the victims' stories to reach any conclusion. Although poisoning by hyoscine appears quite often in the media as an aid for raping, kidnapping, killing or robbery, the effects of this drug and the way it is applied by criminals (transdermal injection, on playing cards and papers etc.) are often exaggerated, especially skin exposure, as the dose that can be absorbed by the skin is too low to have any effect. Hyoscine transdermal patches must be used for hours to days.
The name "burundanga" derives from being an extract of the Brugmansia plant.
Between 1998 and 2004, 13% of emergency room admissions for poisoning with criminal intentions in a clinic of Bogotá, Colombia, have been attributed to hyoscine, and 44% to benzodiazepines. Most commonly, the person has been poisoned by a robber who gave the victim a scopolamine-laced beverage, in the hope that the victim would become unconscious or unable to effectively resist the robbery. A Turkish-Canadian Professor, Ramazan Gençay, who was in the Department of Economics at Simon Fraser University was found dead in Colombia on 24 December 2018, with questions of if he was poisoned by hyoscine.
In 2019, a man was charged with murder after two men in London were found to have been poisoned with hyoscine. One of the men, Adrian Murphy, died.
Hyoscine is used as a research tool to study memory encoding. Initially, in human trials, relatively low doses of the muscarinic receptor antagonist, scopolamine, were found to induce temporary cognitive defects. Since then, scopolamine has become a standard drug for experimentally inducing cognitive defects in animals. Results in primates suggest that acetylcholine is involved in the encoding of new information into long term memory.
Hyoscine produces detrimental effects on short-term memory, memory acquisition, learning, visual recognition memory, visuospatial praxis, visuospatial memory, visuoperceptual function, verbal recall and psychomotor speed. However, scopolamine does not seem to impair recognition and memory retrieval. Acetylcholine projections in hippocampal neurons, which are vital mediating in mediating long term potentiation, are inhibited by scopolamine. Hyoscine also inhibits cholinergic mediated glutamate release in hippocampal neurons which assist in depolarization, potentiation of action potential, and synaptic suppression. Hyoscine's effects on acetylcholine and glutamate release in the hippocampus favors retrieval dominant cognitive functioning. Hyoscine has been used to model the defects in cholinergic function for models of Alzheimer’s, dementia, fragile X syndrome, and Down syndrome.
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