BETAHISTINE AN betahistine dihydrochloride 16mg tablet blister pack

Country: Australia

Language: English

Source: Department of Health (Therapeutic Goods Administration)

Active ingredient:

betahistine dihydrochloride

Available from:

Southern Cross Pharma Pty Ltd

INN (International Name):

betahistine dihydrochloride

Patient Information leaflet

________________________________________________________________________________
C: Products/Betahistine/CMI 3Feb15
Page
1 of 3
BETAHISTINE AN
_Betahistine dihydrochloride_
CONSUMER MEDICINE INFORMATION
_ _
PLEASE READ THIS LEAFLET CAREFULLY BEFORE YOU START BETAHISTINE AN.
What is in this leaflet
This leaflet answers some common
questions about Betahistine AN tablets.
It does not contain all of the available
information. It does not take the place
of talking to your doctor or pharmacist.
IF YOU HAVE ANY CONCERNS ABOUT
TAKING THIS MEDICINE, ASK YOUR DOCTOR
OR PHARMACIST.
All medicines have risks and benefits.
Your doctor has weighed the risks of
you taking Betahistine AN tablets
against the benefits this medicine is
expected to have for you.
KEEP THIS LEAFLET WITH THE MEDICINE.
You may need to read it again.
What Betahistine AN is
used for
Betahistine AN is used to treat a
disorder of the working of your inner
ear. This disorder may include one or
more of the following symptoms, in
one or both ears:

Ringing in the ears (tinnitus)

Loss of clear hearing

Problems with balance (vertigo)
These symptoms may also be
associated with nausea, vomiting and
headache. Often these symptoms
together are referred to as Méniere's
Syndrome.
Based on animal studies, the active
ingredient of Betahistine AN tablets,
betahistine dihydrochloride, works by
improving the blood flow of the inner
ear and restoring it to normal. It also
acts on the nerve endings in the inner
ear to normalise the way in which the
nerves respond to outside influences.
YOUR DOCTOR MAY HAVE PRESCRIBED
BETAHISTINE AN FOR ANOTHER REASON.
ASK YOUR DOCTOR IF YOU HAVE ANY
QUESTIONS ABOUT WHY BETAHISTINE AN
HAS BEEN PRESCRIBED FOR YOU.
There is no evidence that Betahistine
AN is addictive.
This medicine is available only with a
doctor's prescription.
Before you take
Betahistine AN
_When you must not take it _
DO NOT TAKE BETAHISTINE AN IF:

you are pregnant or intend to
become pregnant. Betahistine AN
may affect your developing baby
if taken during pr

Summary of Product characteristics

Betahistine/PI 04mar15
04/03/15
Page 1 of 5
PRODUCT INFORMATION
BETAHISTINE AN
NAME OF THE MEDICINE
Betahistine dihydrochloride is chemically identified as 2-[2-
ethylamino)ethyl]pyridine dihydrochloride.
Molecular formula: C
8
H
14
Cl
2
N
2
MW: 209.1
The chemical structure of betahistine dihydrochloride is:
CAS number: 5579-84-0
DESCRIPTION
Betahistine dihydrochloride is a white to almost white crystalline
powder
which is very hygroscopic. The product is very soluble in water,
freely
soluble in methanol and 96% ethanol, and slightly soluble in
isopropanol.
The pKa values are 3.5 and 9.7.
Chemically, betahistine has a close resemblance to histamine.
BETAHISTINE AN tablets contain Betahistine dihydrochloride 16 mg and
the
following excipients: Lactose, maize starch, microcrystalline
cellulose,
anhydrous citric acid, povidone, crospovidone and hydrogenated
vegetable
oil.
PHARMACOLOGY
PHARMACODYNAMICS
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.
Betahistine/PI 04mar15
04/03/15
Page 2 of 5
In further animal pharmacological studies, betahistine was found to
have
weak H1-receptor agonistic and considerable H3-antagonistic 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 in cats. The importance of this
observation in
the action against Meniere's syndrome or vestibular vertigo, however,
remains unclear.
PHARMACOKINETICS
In humans, orally administered doses of betahistine dihydrochloride
are
rapidly and completely absorbed from the gastrointestinal tract. The
drug is
rapidly metabolised to one major metabolite, 2-pyridylacetic acid, and
excreted in the urine. Studies with radiolabelled betahistine have
demonstrated a plasma half-life of 3.4 hours