Potassium bromide is a reagent with interesting properties

Potassium bromide

Potassium bromide

(K Br) is a salt widely used as an anticonvulsant and sedative in the late 19th and early 20th centuries, and was not available over the counter in the United States until 1975. Its action is due to bromide ion (sodium bromide is no less effective). Potassium bromide is used as a veterinary drug, as an antiepileptic drug for dogs.

Potassium bromide under standard conditions is a white crystalline powder. Easily dissolves in water; insoluble in acetonitrile. In dilute aqueous solution, potassium bromide tastes sweet, at higher concentrations it tastes bitter, and tastes salty when the concentration is even higher. [ how long?

] These effects are mainly due to the properties of the potassium ion—sodium bromide tastes salty at any concentration.
In high concentrations, potassium bromide is highly irritating to the gastric mucosa, causing nausea and sometimes vomiting (a typical effect of all soluble potassium salts). [ citation needed
]

Chemical properties

According to the pharmacopoeia, potassium bromide is the potassium salt of hydrobromic acid . In appearance, these are white or colorless crystals, fine crystalline powder, taste salty (sweet in a dilute solution, bitter in a concentrated solution). The formula for Potassium Bromide is quite simple: BrK . Judging by the formula, the chemical bond in potassium bromide is ionic. The substance, when released into water, undergoes a dissociation reaction (not hydrolysis), and is slightly soluble in ethyl alcohol. Molecular weight of chemical. compounds = 119 grams per mole. If we describe in detail the mechanism of dissolution of Potassium Bromide in water, it can be noted that the substance undergoes complete dissociation due to the fact that the salt was formed by a strong acid and a strong base.

The product is used as a source of bromide ions to produce silver bromide, which is used in the manufacture of film and photo films. Using Potassium Bromide, IR spectroscopy of liquid substances is carried out. In medicine, the medicine is used as a sedative and anticonvulsant (at the moment it is more actively used in veterinary medicine).

What foods contain potassium?

A deficiency of the substance in the body can lead to cramps, muscle weakness, dry skin and unhealthy hair, heart problems, and heart attacks. Potassium is found in bee products, apple cider vinegar, legumes, potatoes, bananas, carrots, rye bread, melons, dried fruits and nuts. The daily requirement for a person is 2 grams. Potassium bromide does not affect the potassium content in the body, it just has a calming effect on the nervous system.

Physical properties:

Pharmacodynamics and pharmacokinetics

The medicine enhances inhibition processes in the cerebral cortex, stabilizes the functioning of the central nervous system. Has an anticonvulsant effect.

The compound is well absorbed in the digestive tract and binds to plasma proteins. It is excreted slowly; within 12 days, the plasma concentration of the drug is halved. Potassium bromide is excreted through the kidneys and intestines, mammary and sweat glands. The medicine has the ability to accumulate in the body.

Applications [edit]

Medicine and veterinary medicine[edit]

Bottle from PRN Pharmaceutical Company (Pensacola, FL) K • Oral Solution

veterinary pharmaceutical drug potassium bromide
BroVet
(250 mg/ml). The product is intended for use in dogs, primarily as an antiepileptic (to relieve seizures). The pink color of the solution is artificial; Solutions of pure potassium bromide are colorless

The anticonvulsant properties of potassium bromide were first noted by Sir Charles Locock at a meeting of the Royal Medical and Surgical Society in 1857. Bromide may be considered the first effective drug for epilepsy. At that time it was believed that epilepsy was caused by masturbation. [5] Lowcock noted that bromide calmed sexual arousal and thought this was the reason for its success in treating seizures. In the second half of the 19th century, potassium bromide was used on a huge scale to calm seizures and nervous disorders, and in some hospitals it was consumed up to several tons per year (the dose for a given person was several tons). grams per day). [5]By the early 20th century, the generic word had become so widely associated with the condition that bromide came to mean a dull, staid person or a boring platitude uttered by such a person. [6]

There was no better cure for epilepsy until phenobarbital in 1912. Historically, the British Army laced soldiers' tea with bromide to suppress sexual arousal, but this is probably untrue as it would also reduce alertness in battle. Similar stories exist about some substances. [ citation needed

]

Bromide compounds, especially sodium bromide, remained in over-the-counter sedatives and headache medications (such as the original Bromo-Seltzer formulation) in the United States until 1975, when bromides were banned from all over-the-counter medications due to chronic toxicity. [7] Bromide's extremely long half-life in the body makes dosing difficult without side effects. The medical use of bromides in the United States was discontinued at this time, since by that time many better short-acting sedatives were known.

Potassium bromide is used in veterinary medicine to treat epilepsy in dogs, either as first-line treatment or in addition to phenobarbital when seizures are not sufficiently controlled by phenobarbital alone. The use of bromide in cats is limited because it carries a significant risk of causing pneumonia (pneumonitis). The use of bromide as a therapeutic drug in animals means that veterinary medical diagnostic laboratories can routinely measure serum bromide levels when ordered by a veterinarian, whereas human medical diagnostic laboratories in the United States do not routinely measure bromide. test.

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 people, especially children and adolescents. [8] These indications include severe generalized tonic-clonic seizures, tonic-clonic seizures in early childhood, and severe myoclonic seizures in childhood. Adults who responded positively to the drug in childhood/adolescence may continue treatment. Potassium bromide tablets are sold under the brand name Dibro-Be mono

(for recipes only). The drug has almost complete bioavailability, but the bromide ion has a relatively long half-life in the blood - 12 days [5]. This makes the regulation and dosing of bromide salts difficult. Bromide does not affect the absorption or elimination of any other anticonvulsant, although it interacts strongly with chloride in the body, normal absorption and elimination from the body greatly influences the elimination of bromide. [5]

The therapeutic index (ratio of effectiveness to toxicity) for bromide is small. As with other antiepileptic drugs, sometimes even therapeutic doses (3 to 5 grams per day, taking 6 to 8 weeks to reach stable levels) can cause toxicity. Often indistinguishable from "expected" side effects, these include:

• Bromism
  This is a reaction of the central nervous system. These may include:

depression lethargy, drowsiness (ranging from daytime sleepiness to coma) loss of appetite and cachexia, nausea/vomiting with excisosis (loss of body fluids) loss of reflexes or pathological reflexes clonic seizures tremor ataxia loss of nerve sensation paresis cerebral edema with associated headache and papilledema nerve eye delirium: confusion, abnormal speech, loss of concentration and memory, aggressiveness psychosis

• Acne dermatitis and other forms of skin diseases, as well as hypersecretion of mucous membranes in the lungs, may also occur. Asthma and rhinitis may worsen. Rarely, tongue disorders, aphthous stomatitis, halitosis and constipation occur.

Optics[edit]

Potassium bromide is transparent from near ultraviolet to long-wave infrared (0.25-25 microns) and has no noticeable optical absorption lines in the high transmittance region. It is widely used as infrared optical windows and components for general spectroscopy due to its wide spectral range. In infrared spectroscopy, samples are analyzed by crushing powdered potassium bromide and pressing into a disk. Alternatively, samples can be analyzed as a liquid film (neat, in solution, or mixed with nujol) between two polished potassium bromide discs. [9]

Due to its high solubility and hygroscopicity, it must be stored in a dry place. The refractive index is about 1.55 at 1.0 µm.

Photography [edit]

In addition to producing silver bromide, potassium bromide is used as a limiter in black and white developer formulas. It improves the discrimination between exposed and unexposed silver halide crystals and thus reduces fog. [10]

Side effects

Bromism may occur during treatment with the drug :

• lethargy, general weakness and lethargy;
• slow speech, decreased hearing and vision, apathy;
• ataxia , irritation, apathy, memory loss;
• skin rashes, inflammatory processes on the mucous membrane ( rhinitis , bronchitis , cough, diarrhea , inflammation of the conjunctiva), gastralgia , other allergic reactions.

Links[edit]

1. "Potassium bromide 221864".
2. "ChemIDplus - Potassium Bromide". chem.sis.nlm.nih.gov
   .
3. “Labchem MSDS, sec. 16, p. 6" (PDF).
4. "Potassium bromide". Bulletin of Titi Tudoranch
   .
5. ^ abcd Goodman; Gilman (1970). "Chapter 10: Hypnotics and sedatives." Pharmacological basis of therapy
   (4th ed.). London: Macmillan. pp. 121–2.
6. Metcalfe, Alan A. (2004). Predicting new words - the secrets of their success. Boston: Houghton Mifflin Harcourt. pp. 36 -42. ISBN 978-0-618-13006-1. Retrieved August 27, 2022.
7. Adams, Samuel Hopkins (1905). The Great American Fraud. American Medical Association Press. The Great American Fraud.
8. German booklet
9. Reusch, W. "Infrared spectroscopy". Virtual Text of Organic Chemistry
   . Archived from the original on October 27, 2007. Retrieved December 18, 2007.
10. Anchell, Stephen; Troops, Bill (1998). The Film Development Cookbook
    . Boston: Focal Press. paragraph 28.

Physiological action

Widely used as an anticonvulsant and sedative in the late 19th and early 20th centuries. Its action is based on the physiological effect of bromide ion (sodium bromide is less effective). KBr is currently used as a veterinary drug, as an anticonvulsant drug for dogs and cats.

In dilute aqueous solutions, potassium bromide gives the solution a sweet taste; at higher concentrations, the solution has a bitter taste (these effects are mainly due to the action of the potassium ion).

At high concentrations, potassium bromide severely irritates the gastric mucosa, leading to nausea and vomiting.

The lethal dose LD50 is 3070 mg/kg.