5579-84-0 Usage
Description
Betahistine dihydrochloride, also known as Serc (Unimed), is an orally active histamine analog used to control vertigo, lack of hearing, and tinnitus related to Ménière’s disease. It is a white to light yellow crystalline powder that functions by reducing the pressure of the membranous labyrinth, enhancing microvasculature circulation, and improving the signs of Ménière’s disease. However, due to its short half-life of about 3-4 hours, it requires frequent administration, making it an ideal candidate for controlled release preparations.
Uses
Used in Pharmaceutical Industry:
Betahistine dihydrochloride is used as a pharmaceutical secondary standard for application in quality control, providing a convenient and cost-effective alternative to the preparation of in-house working standards.
Used in Treatment of Ménière's Disease:
Betahistine dihydrochloride is used as a medication for treating vertigo associated with Ménière's disease. It helps reduce the number of episodes of vertigo by decreasing the pressure in the ear, which is believed to contribute to the sense of dizziness, nausea, ringing in the ears, and hearing loss experienced by people with Ménière's disease.
Used in Treatment of Thrombocytopenia:
Betahistine dihydrochloride is used as a therapeutic agent for thrombocytopenia, effectively treating idiopathic thrombocytopenic purpura and cirrhosis due to hepatitis C.
Pharmacokinetics
Absorption:Betahistine dihydrochloride is readily and almost completely absorbed after oral administration from all parts of the gastro-intestinal tract, and peak plasma concentrations of 14C-labelled betahistine dihydrochloride are attained one hour after oral administration to fasting subjects.After absorption, the drug is rapidly and almost completely metabolized into 2-pyridylacetic acid. Plasma levels of betahistine are very low. Pharmacokinetic analyses are therefore based on 2-PAA measurements in plasma and urine.Under fed conditions Cmax is lower compared to fasted conditions. However, total absorption of betahistine is similar under both conditions, indicating that food intake only slows down the absorption of betahistine.Distribution:The percentage of betahistine that is bound by blood plasma proteins is less than 5 %.Biotransformation:After absorption, betahistine is rapidly and almost completely metabolized into 2-PAA (which has no pharmacological activity). After oral administration of betahistine the plasma (and urinary) concentration of 2-PAA reaches its maximum 1 hour after intake and declines with a half-life of about 3.5 hours.Excretion:2-PAA is readily excreted in the urine. In the dose range between 8 and 48 mg, about 85% of the original dose is recovered in the urine. Renal or faecal excretion of betahistine itself is of minor importance.Betahistine dihydrochloride is eliminated by the kidney with 85 - 90% of the radioactivity of an 8 mg dose appearing in the urine over 56 hours. Maximum excretion rates are reached within 2 hours of administration. Plasma levels of the parent drug are below the limits of detection of the assay.Bioavailability has therefore been assessed from urinary excretion of its main metabolite, 2-pyridylacetic acid.There is no evidence for presystemic metabolism. Biliary excretion is not important as a route of elimination of either the drug or its metabolites in the rat and is unlikely to be so in man.Linearity:Recovery rates are constant over the oral dose range of 8 – 48 mg indicating that the pharmacokinetics of betahistine are linear, and suggesting that the involved metabolic pathway is not saturated.
Clinical Use
Treatment of vertigo, tinnitus and hearing loss associated
with Ménière’s syndrome
Side effects
Stomach upset, nausea, and headache may occur. This medication may also rarely cause drowsiness. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including:rashitching/swelling (especially of the face/tongue/throat)severe dizzinesstrouble breathingThis is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
Drug interactions
Potentially hazardous interactions with other drugs
None known
Metabolism
Betahistine is excreted almost exclusively in the urine as
2-pyridylacetic acid within 24 hours of administration.
No unchanged betahistine has been detected.
Mode of action
Betahistine acts both as a partial histamine H1-receptor agonist and histamine H3-receptor antagonist also in neuronal tissue, and has negligible H2-receptor activity. Betahistine increases histamine turnover and release by blocking presynaptic H3-receptors and inducing H3-receptor downregulation.Betahistine dihydrochloride is a histamine-like drug in which pharmacological activity can be attributed to a specific effects and/or more direct influences on recovery mechanisms the vestibular nuclei. It has weak agonist activity at histamine H1 receptors and moderate antagonist activity at H3; receptors. The antagonist action of betahistine dihydrochloride at the H3: receptor can be expected to potentiate the release of presynaptic histamine in vivo by blocking the auto-inhibitory feedback at histaminergic terminals, its action on medial vestibular nucleus cells is to significantly reduce their responsiveness to histamine. This action of betahistine dihydrochloride occurs at post-synaptic H1 receptors, since betahistine dihydrochloride lacks any effect at H2 receptors. The effects of betahistine dihydrochloride are thus consistent with a partial agonist action at these receptors, with betahistine dihydrochloride having little excitatory action on its own but reducing the excitatory responses to histamine by occupying H1 receptor sites.
Check Digit Verification of cas no
The CAS Registry Mumber 5579-84-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 5,5,7 and 9 respectively; the second part has 2 digits, 8 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 5579-84:
(6*5)+(5*5)+(4*7)+(3*9)+(2*8)+(1*4)=130
130 % 10 = 0
So 5579-84-0 is a valid CAS Registry Number.
InChI:InChI=1/C8H12N2.2ClH/c1-9-7-5-8-4-2-3-6-10-8;;/h2-4,6,9H,5,7H2,1H3;2*1H
5579-84-0Relevant articles and documents
Preparation method of orthographic optimizing betahistine hydrochloride
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, (2018/07/30)
The invention discloses a preparation method of orthographic optimizing betahistine hydrochloride, and relates to the field of drug preparation. The preparation method includes the steps: adding raw materials into a reaction bottle according to the feeding ratio (molar ratio) of 2-methylpyridine to paraformaldehyde of 1:0.57, leading in nitrogen, stirring mixture for 20 hours at the temperature of125 DEG C and at 4 barometric pressure, performing reduced pressure distillation, and collecting distillation cut at the temperature of 130-145 DEG C and under the pressure of 16mm mercury columns toobtain light-yellow oily 2-hydroxyethyl pyridine; adding the 2-hydroxyethyl pyridine into a three-opening bottle, adding sodium hydroxide according to the feeding ratio of 2-(2-Hydroxyethyl)pyridineto sodium hydroxide of 1:0.05, heating the mixture to reach 95-100 DEG C, stirring the mixture for 2 hours, removing a water layer, performing reduced pressure distillation on an oil layer, and collecting the distillation cut at the temperature of 65-70 DEG C and under the pressure of 17mm mercury columns to obtain 2-vinylpyridine. The preparation method is simple in technological process, safe tooperate and mild in reaction, production efficiency and product quality can be greatly improved, and production cost is reduced.