Betahistine Hydrochloride Betahistine Hydrochloride's chemical name is 2 (2' meihylaminoethyl) pyridine dihydrochloride.

Betahistine Hydrochloride is a drug resembling naturally occurring histamine in some of its effects and is used as a treatment for Meniere's disease, a condition caused by the pressure of excess fluid in the inner ear. When taken regularly Betahistine Hydrochloride seems to reduce the frequency and severity of the attacks of nausea and vertigo that characterize this condition. It is thought to work by improving blood flow in the small blood vessels of the inner ear. Betahistine Hydrochloride as a treatment is not always successful and surgery is sometimes required.

Possible Side Effects Like any drug, Betahistine Hydrochloride can have side effects. Reported adverse effects are minor. Occasionaly patients have experienced gastric upset, nausea and headache.

Is Betahistine Hydrochloride A Cure For Meniere's Disease?  While Betahistine Hydrochloride is not a "cure" for Meniere's, some of the research has verified that Betahistine Hydrochloride can eliminate many of the symptoms associated with Meniere's Disease.

Action: Betahistine was found to have a histamine-like action in animals. Since parenteral (by injection) 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 testing. In addition, the absorption, metabolism and action of betahistine when administered by the oral route are not fully understood.

Indications: Betahistine Hydrochloride may be of value in reducing the number of episodes of vertigo or severity in Meniere's disease.

Clinical Use: The extremely variable course of Meniere's disease makes it almost impossible to predict. No studies are available comparing betahistine with other anti-vertigo agents. Betahistine Hydrochloride 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 Betahistine Hydrochloride 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 is characterized by recurrent episodes of vertigo (the sensation of spinning or whirling) accompanied by tinnitus (ringing, roaring, or buzzing sound in the ears or head) and hearing loss. Nausea and vomiting may also occur. The vertigo lasts from a few minutes to several hours. In general, early Meniere's is featured by hearing levels which become worse with attacks and improve even to normal between the attacks, while in late Meniere's hearing loss is less directly related to dizziness.

Contraindications: Several patients with a history of peptic ulcer have experienced a worsening of symptoms while using Betahistine Hydrochloride. Betahistine Hydrochloride is not indicated in the presence of peptic ulcer and in patients with a history of this condition.

Precautions: Although clinical intolerance to Betahistine Hydrochloride by patients with bronchial asthma has not been demonstrated, caution should be exercised if the drug is used in these patients. Betahistine Hydrochloride 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 Betahistine Hydrochloride.

Use In pregnancy: The safety of Betahistine Hydrochloride 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: Occasionally patients have experienced gastric upset, nausea and headache.

Toxicology: The lethal dose of betahistine hydrochloride for the albino rat is 3040 mg./kg. by the oral route. The main signs of toxicity observed were: ataxia, salivation, inactivity, hyperpnea (Increased respiratory rate ), tremors and cyanosis. The pathology revealed severe gastroenteritis. 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 Betahistine Hydrochloride several hundred patients with Meniere's disease were treated. 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. The results of this study favor the efficacy of Betahistine Hydrochloride 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 8mg to 16mg administered orally three times a day. The dosage has ranged from two capsules per day to eight per day. No more than eight are recommended to be taken in any one day.

Betahistine Hydrochloride is not recommended for use in children. As with all drugs, Betahistine Hydrochloride should be kept out of reach of children.

Betahistine for Treatment of Acute Vestibular Vertigo & Meniere's Disease

The clinical efficacy of betahistine has been documented by a series of more than twenty controlled clinical studies, performed in the years 1966-2000. Basic research initially proved that betahistine acts through a vasodilating action on inner ear and cerebral blood flow. Further studies proved that betahistine acts on the central vestibular histaminergic system as a weak HI agonist and a strong H3 antagonist, improving the process of vestibular compensation, and also works on peripheral labyrinthine receptors, reducing the spontaneous firing rate but not the activity induced by thermal or mechanical stimulation.

A study compared the efficacy and safety of betahistine dihydrochloride to that of placebo for treatment of recurrent vertigo resulting from Meniere's disease (MD) or paroxysmal positional vertigo (PPV) of probable vascular origin. The design was double- blind, multi-center, and parallel-group randomized. Eleven Italian centers enrolled 144 patients: 75 of the patients were treated with betahistine (41 MD/34 PPV) and 69 with placebos (40 MD/29 PPV). The betahistine dosage was 16 mg twice per day for 3 months. Compared to the placebo, betahistine had a significant effect on the frequency, intensity and duration of vertigo attacks. Associated symptoms and the quality of1ife also were significantly improved by betahistine. Both the physician's judgment and the patient's opinion on the efficacy and acceptability of the treatment were in agreement as to the superiority of betahistine. The efficacy and safety profile of betahistine in the treatment of vertigo due to peripheral vestibular disorders was confirmed.

A review of the literature on drug therapy for Meniere's disease was made using Medline to search for all publications between January 1978 and September 1998. A total of 152 publications Were identified that specifically dealt with medical treatment for Meniere's disease. Only betahistine and diuretics appear to have proven efficacy in double-blind studies on the long-term control of vertigo. No treatment has a proven beneficial effect on hearing levels or on the long-term evolution of the disease.

In the ENT Clinic of Turku University Hospital (Finland), betahistine was used to treat 613 Meniere's patients at a dose of 8 mg orally three times daily. In about 80% of these patients, the results of therapy were positive. Betahistine has only minimal side-effects and can also be used as maintenance therapy in other forms of vestibular vertigo.

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