Potassium bromide
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3D model (
JSmol ) |
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ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard
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100.028.937 |
PubChem CID
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RTECS number
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
KBr | |
Molar mass | 119.002 g/mol |
Appearance | white solid |
Odor | odorless |
Density | 2.74 g/cm3 |
Melting point | 734 °C (1,353 °F; 1,007 K) |
Boiling point | 1,435 °C (2,615 °F; 1,708 K) |
535 g/L (0 °C) 678 g/L (25 °C) 1020 g/L (100 °C) | |
Solubility | very slightly soluble in diethyl ether |
Solubility in glycerol | 217 g/L |
Solubility in ethanol | 47.6 g/L (80 °C) |
−49.1·10−6 cm3/mol | |
Refractive index (nD)
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1.559 |
Structure | |
Sodium chloride(Face-centered cubic) | |
octahedral
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10.41 D (gas) | |
Pharmacology | |
QN03AX91 (WHO) | |
Hazards | |
GHS labelling: | |
Warning | |
H319 | |
P280, P305+P351+P338, P337+P313[1] | |
NFPA 704 (fire diamond) | |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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3070 mg/kg (oral, rat)[2] |
Related compounds | |
Other anions
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Potassium fluoride Potassium chloride Potassium iodide |
Other cations
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Francium bromide
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Potassium bromide (KBr) is a salt, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries, with over-the-counter use extending to 1975 in the US. Its action is due to the bromide ion (sodium bromide is equally effective). Potassium bromide is used as a veterinary drug, in antiepileptic medication for dogs.
Under standard conditions, potassium bromide is a white crystalline powder. It is freely soluble in water; it is not soluble in acetonitrile. In a dilute aqueous solution, potassium bromide tastes sweet, at higher concentrations it tastes bitter, and tastes salty when the concentration is even higher. These effects are mainly due to the properties of the potassium ion—sodium bromide tastes salty at any concentration. In high concentration, potassium bromide strongly irritates the gastric mucous membrane, causing nausea and sometimes vomiting (a typical effect of all soluble potassium salts).[citation needed]
Chemical properties
Potassium bromide, a typical
Aqueous bromide Br− also forms
Preparation
A traditional method for the manufacture of KBr is the reaction of potassium carbonate with an iron(III, II) bromide, Fe3Br8, made by treating scrap iron under water with excess bromine:[4]
Applications
Medical and veterinary
The anticonvulsant properties of potassium bromide were first noted by Sir Charles Locock at a meeting of the Royal Medical and Chirurgical Society in 1857. Bromide can be regarded as the first effective medication for epilepsy. At the time, it was commonly thought that epilepsy was caused by masturbation.[6] Locock noted that bromide calmed sexual excitement and thought this was responsible for his success in treating seizures. In the latter half of the 19th century, potassium bromide was used for the calming of seizure and nervous disorders on an enormous scale, with the use by single hospitals being as much as several tons a year (the dose for a given person being a few grams per day).[6] By the beginning of the 20th century the generic word had become so widely associated with being sedate that bromide came to mean a dull, sedate person or a boring platitude uttered by such a person.[7]
There was not a better epilepsy drug until phenobarbital in 1912. The British Army has historically been claimed to lace soldiers' tea with bromide to quell sexual arousal and in the Victorian era prisoners in England were compulsorily dosed with the chemical.[8][9]
Bromide compounds, especially sodium bromide, remained in over-the-counter sedatives and headache remedies (such as the original formulation of Bromo-Seltzer) in the US until 1975, when bromides were outlawed in all over-the-counter medicines, due to chronic toxicity.[10] Bromide's exceedingly long half life in the body made it difficult to dose without side effects. Medical use of bromides in the US was discontinued at this time, as many better and shorter-acting sedatives were known by then.
Potassium bromide is used in veterinary medicine to treat
Potassium bromide is not approved by the US Food and Drug Administration (FDA) for use in humans to control seizures. In Germany, it is still approved as an antiepileptic drug for humans, particularly children and adolescents.[11] These indications include severe forms of generalized tonic-clonic seizures, early-childhood-related tonic–clonic seizures, and also severe myoclonic seizures during childhood. Adults who have reacted positively to the drug during childhood/adolescence may continue treatment. Potassium bromide tablets are sold under the brand name Dibro-Be mono (Rx-only). The drug has almost complete bioavailability, but the bromide ion has a relatively long half life of 12 days in the blood,[6] making bromide salts difficult to adjust and dose. Bromide is not known to interfere with the absorption or excretion of any other anticonvulsant, though it does have strong interactions with chloride in the body, the normal body uptake and excretion of which strongly influences bromide's excretion.[6]
The therapeutic index (ratio of effectiveness to toxicity) for bromide is small. As with other antiepileptics, sometimes even therapeutic doses (3 to 5 grams per day, taking 6 to 8 weeks to reach stable levels) may give rise to intoxication. Often indistinguishable from 'expected' side-effects, these include:
- Bromism These are central nervous system reactions. They may include:
- depression,
- lethargy, somnolence (from daytime sleepiness to coma)
- loss of appetite and cachexia, nausea/emesis with exicosis (loss of body fluid)
- loss of reflexesor pathologic reflexes
- clonic seizures
- tremor
- ataxia
- loss of neural sensitivity
- paresis
- cerebral edema with associated headache and papilledema of the eyes
- delirium: confusion, abnormal speech, loss of concentration and memory, aggressiveness
- psychosis
- Acne-form dermatitis and other forms of skin disease may also be seen, as well as mucous hypersecretion in the lungs. Asthma and rhinitis may worsen. Rarely, tongue disorder, bad breath, and constipationoccur.
Optics
Potassium bromide is transparent from the near
Due to its high solubility and
Photography
In addition to manufacture of silver bromide, potassium bromide is used as a restrainer in
References
- ^ "Potassium bromide 221864". Archived from the original on 3 June 2021. Retrieved 1 October 2018.
- ^ "ChemIDplus — Potassium bromide". chem.sis.nlm.nih.gov. Archived from the original on 12 August 2014. Retrieved 11 August 2014.
- ^ "Labchem MSDS, sec. 16, p. 6" (PDF). Archived (PDF) from the original on 18 December 2021. Retrieved 27 November 2018.
- ^ "Potassium bromide". The Titi Tudorancea Bulletin. Archived from the original on 10 December 2015. Retrieved 9 December 2014.
- ^ a b K-BROVET 250- potassium bromide tablet, chewable drug label/data at DailyMed from U.S. National Library of Medicine, National Institutes of Health.
- ^ a b c d Goodman; Gilman (1970). "Chapter 10: Hypnotics and Sedatives". The Pharmacological Basis of Therapeutics (4th ed.). London: MacMillan. pp. 121–2.
- ISBN 978-0-618-13006-1. Retrieved 27 August 2017.
- ^ "De Profundis by WILDE, Oscar - Jonkers Rare Books". www.jonkers.co.uk. Archived from the original on 19 June 2023.
- ^ "The Trials of Oscar Wilde: Downfall and Prison by The Rest Is History | Podchaser". Archived from the original on 19 June 2023.
- ^ Adams, Samuel Hopkins (1905). The Great American Fraud. Press of the American Medical Association.
The Great American Fraud.
- ^ "German leaflet". Archived from the original on 26 March 2017. Retrieved 13 November 2016.
- ^ Reusch, W. "Infrared Spectroscopy". VirtualText of Organic Chemistry. Archived from the original on 27 October 2007. Retrieved 18 December 2007.
- ^ Anchell, Stephen; Troop, Bill (1998). The Film Developing Cookbook. Boston: Focal Press. p. 28.