BRAND NAMES
- Canada: Serc PI
- International: Betaserc
- Italy: Betaserc, Microser, Vertiserc
- France: Lectil
- Germany: Aequamen, Betavert, Vasomotal
- Lebanon: Alvigo, Betaserc
- Netherlands: Betaserc, Polvertic
- Spain: Serc
- Switzerland: Betaserc
 MECHANISM OF ACTION
Betahistine dihydrochloride is a histamine analogue for oral administration. The precise mechanism of action has not been fully elucidated. In pharmacological animal studies, betahistine dihydrochloride was shown to have H3-antagonistic and weak H1-agonistic activities on the CNS and autonomic nervous system. Furthermore, it was shown that betahistine dihydrochloride has a dose-dependent inhibitory effect on the activity of the medial and lateral vestibular nuclei. In addition, an improved blood circulation was shown in the vascular stria and a reduced endolymphatic pressure in the inner ear, probably due to relaxation of the precapillary sphincters of the microcirculation of the inner ear. The onset of effect varies between a few days and weeks.
Ménière's disease characterised by attacks of hearing loss, tinnitus and disabling vertigo.
Adult and elderly patients
The recommended initial dose is 24 mg in 2 or 3 single doses.
If this dosage is insufficient, the daily dose can be increased to a maximum of 48 mg
Betahistine is not recommended for the treatment of children and adolescents below 18 years of age.
The tablets should be taken with some fluid, either during or after meals. To ensure a satisfactory result, treatment should be continued for several months.
- hypersensitivity to the active substance or to any of the excipients
- phaeochromocytoma: As betahistine dihydrochloride is a synthetic histamine analogue, it can induce catecholamine release from the tumour, which can lead to severe hypertension.
- during pregnancy and lactation
 WARNINGS AND PRECAUTIONS
Caution is advised in the treatment of patients with:
- peptic ulcer (including a history of this disorder), as dyspepsia may occasionally occur in patients undergoing betahistine dihydrochloride treatment;
- bronchial asthma;
- urticaria, exanthema or allergic rhinitis, as these symptoms may worsen;
- pronounced hypotension.
- concurrent administration of antihistamines
As betahistine is a histamine analogue, concurrent administration of H1 antagonists may cause a mutual attenuation of effect of the active agents.
 PREGNANCY AND LACTATION
Betahistine must not be administered during pregnancy and lactation, as no adequate animal studies are available and there has been no experience with use during human pregnancy and lactation.
 SIDE EFFECTS
The following undesirable effects have been reported at the approximate frequencies shown.
Very common (≥ 1/10)
Common (≥ 1/100 to < 1/10)
Uncommon (≥ 1/1,000 to < 1/100)
Rare (≥ 1/10,000 to < 1/1,000)
Very rare (< 1/10,000)
Not known (cannot be estimated from the available data)
rare: beating of the heart
Nervous system disorders:
rare: Headache, somnolence
Respiratory, thoracic and mediastinal disorders:
rare: Pre-existing bronchial asthma may worsen.
rare: Gastric discomfort and pain, heartburn, vomiting, nausea, indigestion. Pre-existing gastrointestinal ulcer may worsen.
Skin and subcutaneous tissue disorders:
rare: rash, urticaria, pruritus
rare: sensation of heat