The SERC Page
© 1997-1998 George B.
Martin
SERC (Betahistine Hydrochloride)
and the Meniere's Patient
SERC (Betahistine Hydrochloride)
Research
SERC (Betahistine Hydrochloride)
Package Insert
Without going into too much detail for now, let me just say that some of us have suffered a lot with this problem and the typical remedies such as [endolymphatic] sac surgery, diet, various blood vessel dilators, diuretics, and Antivert just won't take care of the problem. I have been through all of the aforementioned treatments with very little success and was very discouraged.
In July 1993 I had a major Meniere's Disease attack and I was convinced that I was having a heart attack. My wife called EMS [paramedics] and I was taken to the hospital where I stayed overnight to get my nausea under control. From that day until mid December I had daily attacks and some days several of them. (A previous shunt operation had no effect at all.) Nothing worked but at least with large doses of valium and transdermal neck patches (used to prevent seasickness) I was calm; actually I was like a zombie. As soon as the sedatives wore off, I was back in the swirl. I really began thinking that life was too short to tolerate such a style
About this time I joined the National Meniere's support group of Tennessee [The Ear Foundation's Meniere's Network]. I read a letter to the editor in their "Steady" paper [monthly newsletter] reporting success using a medication called SERC (betahistine hydrochloride). I contacted the letter writer and received information on how to obtain the drug and have had tremendous success with its use. I have not had an attack since then and only know that I still have Meniere's when I try to cut back too much on my dosage. Unfortunately, SERC is not available in USA, but it is used in over 70 countries in the world as one of the primary treatments for Meniere's disease. Even though this seems to be a miracle drug for many of us, it fails to alleviate the problems for a few. Research shows that it is about 80% effective. I do wear 2 hearing aids, and have heavy tinnitus in the left ear. I have a 95db loss in the left ear and 65 db loss in the right one. But I have no dizziness, nausea, or full feeling in the head nor that questionable mental condition (called brain fog) that many of us have had. I feel great and hope that you do too.
The local U.S. doctors can have little to do with SERC as this drug is not yet approved by the FDA. Doctors are very reluctant to say much about it or perhaps don't even know about it. Most of us who use it and have found success start out by taking 16 mg. 3 times per day until we are free of the vertigo, etc. You will generally not improve the tinnitus or hearing loss, but all the other symptoms will vanish (hopefully). I had to take this heavy dosage for nearly 5 weeks before I was entirely clear of the symptoms, but many find relief in a few days. Then I tapered back on the dosage. I now take 2 at breakfast, 1 at lunch, and 1 at dinner -- with food.
I have a close friend here at the University of Texas who is a chemistry professor -- I took the pharmacy disclosure sheet to him to ask his advice. He said that the chemical makeup of SERC is as near as possible to our own body substance known as histamine and that it would take a ton of it to be harmful. The disclosure sheet does state that you shouldn't take antihistamine and SERC as they are opposite in reaction. Histamine is a natural blood vessel dilator while antihistamine tends to constrict blood vessels.
To secure SERC [in the U.S.] today, one must either see a Canadian physician and be under his/her care to secure a prescription from a [Canadian] pharmacy, or go to Mexico and buy it as an over-the-counter drug.
I have contacted the distributor of SERC, located in a suburb of Chicago. They have informed me that their company has been licensed to build a factory for production here in the [United] States. The company that makes it is ready to start phase 3 of testing for the USA and I have been told that this is testing on people (don't know this for a fact). Someday it will be available here in the States (if we can live that long).
Although you may have seen my patient report (above) concerning my successful use of the drug SERC, I felt that you may like to see SOME of the research that has verified that SERC eliminates most of the symptoms associated with Meniere's Disease.
Here is a copy of the disclosure sheet for SERC that I received from a Canadian source. The tablets in Canada are distributed by Sanofi Winthrop, Markham, Ontario, L3R 6H3, for Unimed, Inc.
SERC (Betahistine hydrochloride)
TABLETS DESCRIPTION AND CHEMISTRY:
SERC is the proprietary name for a histamine-like drug generically designated as betahistine hydrochloride. The chemical name is 2 (2' meihylaminoethyl) pyridine dihydrochloride. There is some similarity in structure between betahistine and histamine.
ACTION:
Betahistine was found to have a histamine-like action in animals. Since parenteral histamine has been used in the treatment of Meniere's disease, studies were conducted to test the action of betahistine in this condition. Unlike some other anti-vertigo drugs, testing with nystagmus induced by caloric and rotational stimulation has demonstrated that betahistine does not decrease the vestibular response, as recorded by electronystagmography. In addition, the absorption, metabolism and action of betahistine when administered by the oral route are not known. However, clinical studies indicate that SERC may be useful in reducing the vertigo of Meniere's disease.
INDICATIONS:
SERC may be of value in reducing the episodes of vertigo in Meniere's disease.
CLINICAL USE:
The extremely variable course of Meniere's disease makes it almost impossible to predict. Consequently, assessment of the results of treatment is fraught with difficulties since spontaneous remissions or a placebo effect cannot be excluded, short of conducting prolonged studies extending over a period of years. The implication is that some information must be accepted from controlled trials falling short of an entirely acceptable design. In addition , most trials with betahistine have included a choice of patients with frequent episodes of vertigo that may not be representative of a cross section of patients with Meniere's disease.
No studies are available comparing betahistine with other antivertigo agents. SERC has not been demonstrated to have any effect on the evolution or progression of Meniere's disease and it appears not to eliminate the development of incapacitating vertigo and the subsequent need for surgery in some patients.
No claim is made for the effectiveness of SERC in the symptomatic treatment of any form of vertigo other than that associated with Meniere's disease. It also has not been established that betahistine has any effect on other manifestations of Meniere's disease.
Meniere's disease, or idiopathic labyrinthine hydrops, is characterized clinically by recurrent episodes of vertigo accompanied by, usually unilateral, tinnitus and hearing loss. Nausea and vomiting may also occur. The vertigo lasts from a few minutes to several hours. Other forms of aural vertigo may be distinguished only because they tend to last longer. As a rule, between dizzy spells there are no other complaints save for varying levels of hearing and tinnitus. The prognosis in individual patients with Meniere's is difficult to predict. Some patients have mild or major dizzy spells in frequent clusters, possibly once or twice weekly, for a period of several weeks or months, then have remission of episodes which may last for months or years. Others may have vertiginous attacks only once or twice yearly. Virtually none have daily spells, and continuous vertigo in the sense of dizziness without remission for many days or weeks. In general, hearing is poorer and tinnitus loud when vertiginous attacks are frequent. Hearing may return to normal between attacks in early cases, but as time progresses, hearing slowly deteriorates, whether dizzy spells occur or not. In general, early Meniere's is featured by hearing levels which become worse with vertiginous attacks and improve even to normal between the attacks, while in late Meniere's hearing loss is less directly related to dizziness. The pathology of Meniere's disease consists of distention of the membranous labyrinth associated with accumulation due to overproduction or under absorption of endolymph.
CONTRAINDICATIONS:
Several patients with a history of peptic ulcer have experienced an exacerbation of symptoms while using SERC. Although no causal relation has been established SERC is contraindicated in the presence of peptic ulcer and in patients with a history of this condition. SERC is also contraindicated in patients with pheochromocytoma.
PRECAUTIONS:
Although clinical intolerance to SERC by patients with bronchial asthma has not been demonstrated, caution should be exercised if the drug is used in these patients.
SERC should not be used concurrently with antihistamine agents since no information is available with regard to the possible interaction of these drugs.
The physician should be aware of the possibility of hitherto unreported adverse reactions to SERC.
USE IN PREGNANCY:
The safety of SERC in pregnancy has not been established. Therefore, its use in pregnancy or lactation, or in women of child bearing age requires that its potential benefits be weighed against the possible risks.
ADVERSE REACTIONS:
Occasionaly patients have experienced gastric upset, nausea and headache.
PHARMACOLOGY:
In the course of animal studies, the response to betahistine, following intravenous administration, and its action on a variety of isolated and intact tissues, resembled some of the responses to histamine. Intravenous administration of SERC produced a transient increase in blood flow through the labyrinthine artery in dogs, preceded by a fall in pulse pressure reflecting a systemic response. It is assumed that SERC could act by decreasing endolymphatic pressure as a result of increased vascularization. However, there is no experimental evidence of an increased perfusion of the stria vascularis or evidence that changes occur in the fluid physiology of the inner ear that would decrease distension of the membranous labyrinth. In addition, information on absorption, metabolism and excretion of betahistine hydrochloride has not yet been obtained.
TOXICOLOGY:
The lethal dose of betahistine hydrochloride for the albino rat is 3040 mg./kg. by the oral route. By the intravenous route the lethal dose for the rabbit is 5.1 mg./kg. The main signs of toxicity observed were: ataxia, salivation, inactivity, hyperpnea, tremors and cyanosis. The pathology revealed severe gastroenteritis.
A two-litter reproductive study with rats revealed no adverse effects.
Chronic toxicity studies in dogs given doses up to 25 mg./kg./day for eighteen months, revealed no significant abnormalities in the parameters measured.
CLINICAL STUDIES:
In the course of clinical trials with SERC several hundred patients with Meniere's disease were treated with this product. These studies have ranged from clinical experience with this drug during short or long periods of treatment to double-blind, placebo controlled trials. In view of the unpredictable natural history of Meniere's disease, no judgment of efficacy is possible in many studies with faulty designs or other serious defects.
One study included approximately 60 patients with Meniere's disease, followed in a longitudinal fashion without a concurrent control group. All patients had evaluation of the vestibular function recorded by electronystagmography. The results of this study favor the efficacy of SERC in reducing vertigo. In addition, the vestibular function improved in the majority of patients that had a subjective response to the drug.
Three double-blind placebo controlled studies suggest a possible therapeutic effect of the drug. No untoward clinical effects were noted.
DOSAGE AND ADMINISTRATION:
The usual adult dosage has been one to two tablets (4mg. each) administered orally three times a day. The dosage has ranged from two tablets per day to eight tablets per day. No more than eight tablets are recommended to be taken in any one day.
SERC is not recommended for use in children. As with all drugs, SERC should be kept out of reach of children.
HOW SUPPLIED:
Scored 4 mg. tablets in bottles of 100 tablets.