Summary of Product Characteristics
1 NAME OF THE MEDICINAL PRODUCT
Serc 8mg Tablets
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each tablet contains 8 mg betahistine dihydrochloride.
For a full list of excipients, see section 6.1.
3 PHARMACEUTICAL FORM
A white to almost white, round, flat tablet, imprinted ‘256’ on one face.
4 CLINICAL PARTICULARS
4.1 Therapeutic Indications
Vertigo, tinnitus and hearing loss associated with Ménière's syndrome.
4.2 Posology and method of administration
The usual daily dose is 8 to 16 mg, three times daily taken preferably with meals.
Hypersensitivity to any component of the product.
Use in phaeochromocytoma.
Use concurrently with antihistamines.
Use in children.
4.4 Special warnings and precautions for use
Caution is advised in the treatment of patients with a history of peptic ulcer. Clinical intolerance to Serc in bronchial
asthma patients has been shown in a relatively few patients and therefore caution should be exercised when
administering betahistine to patients with bronchial asthma.
4.5 Interaction with other medicinal products and other forms of interaction
Although an antagonism between Serc and antihistamines could be expected on a theoretical basis, no such interactions
have been reported.
4.6 Fertility, pregnancy and lactation
Irish Medicines Board
Date Printed 25/10/2011 CRN 2107201 page number: 1
4.7 Effects on ability to drive and use machines
It has been shown that at over 4 times the recommended daily dose, betahistine does not affect driving or psychomotor
4.8 Undesirable effects
In some cases mild gastric complaints have been observed. These can normally be dealt with by taking the dose during
meals or by lowering the dose.
Nervous system disorders
In some cases headaches have been reported.
Skin and subcutaneous tissue disorders
In very rare cases cutaneous hypersensitivity reactions have been reported, in particular rash, puritus and urticaria.
A few overdose cases have been reported. In most cases no overdose symptoms were reported. Some patients
experienced mild to moderate symptoms at doses above 200 mg. At a dose of 728 mg a convulsion was reported. In all
cases recovery was complete. Treatment of overdose should include standard supportive measures.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
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
receptor agonistic and considerable H
properties in the CNS 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.
5.2 Pharmacokinetic properties
Betahistine dihydrochloride is completely absorbed after oral administration. Only one metabolite 2-pyridylacetic acid,
which is excreted in the urine, is known.
5.3 Preclinical safety data
There are no pre-clinical data of relevance to the prescriber which are additional to that already included in other
Irish Medicines Board
Date Printed 25/10/2011 CRN 2107201 page number: 2
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Citric acid monohydrate
Colloidal anhydrous silica
6.3 Shelf life
6.4 Special precautions for storage
Do not store above 25°C. Store in the original package.
6.5 Nature and contents of container
120 tablets in blister strips. The blister strips are made of PVC/PVDC film with a covering aluminium foil.
6.6 Special precautions for disposal of a used medicinal product or waste materials derived from
such medicinal product and other handling of the product
No special requirements.
7 MARKETING AUTHORISATION HOLDER
Abbott Healthcare Products Limited
8 MARKETING AUTHORISATION NUMBER
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
Date of first authorisation: 01 April 1979
Date of last renewal: 01 April 2009
10 DATE OF REVISION OF THE TEXT
Irish Medicines Board
Date Printed 25/10/2011 CRN 2107201 page number: 3