Riik: Lõuna-Aafrika Vabariik
keel: inglise
Allikas: South African Health Products Regulatory Authority (SAHPRA)
Schering
SERC tablets SCHEDULING STATUS: S3 PROPRIETARY NAME (and dosage form): SERC tablets COMPOSITION Each Serc tablet contains betahistine dihydrochloride 4 mg. PHARMACOLOGICAL CLASSIFICATION A. 5.6 Histamine. PHARMACOLOGICAL ACTION Betahistine dihydrochloride is an analogue of histamine. Betahistine dihydrochloride is readily absorbed from the gastrointestinal tract. It is converted to two metabolites and peak concentrations in blood of the two metabolites are achieved within 3 to 5 hours. Most of a dose is excreted in the urine, in the form of the metabolites, in about 3 days. The mechanism of action of betahistine is not known. Pharmacological testing in animals has shown that the blood circulation in the striae vascularis of the inner ear improves, probably by means of a relaxation of the precapillary sphincters of the microcirculation of the inner ear. In pharmacological studies, betahistine was found to have weak H 1 receptor agonistic and considerable H 3 antagonistic properties in the central nervous system and autonomic nervous system. Betahistine was also found to have a dose dependent inhibiting effect on spike generation of neurons in lateral and medial vestibular nuclei. The importance of this observation in the action against Ménière’s syndrome or vestibular vertigo, however, remains unclear. INDICATIONS Ménière’s syndrome. CONTRA-INDICATIONS Hypersensitivity to any of the ingredients. Patients with active peptic ulcer. Patients with phaeochromocytoma. DOSAGE AND DIRECTIONS FOR USE Initial dose: Two to four tablets three times daily with meals. Maintenance dose: Six to twelve tablets daily. SIDE EFFECTS AND SPECIAL PRECAUTIONS Gastro-intestinal disturbances, headache and skin rashes have been reported. Special precautions Serc tablets should be given with car Lugege kogu dokumenti