2 vertin

2 vertin

1. 1
MANAGEMENT
OF VERTIGO

2. 2
Management of vertigo
Pharmacotherapy
Adaptation exercises
Surgery

3. 3
A Vertigo Patient
I WANT ..
Fewer attacks every
month
Attacks should not be
as bad as before
Attacks should not
last long

4. 4
Pharmacotherapy
(Antivertigo drugs)
Vasodilators
Antiemetics
Labyrinthine sedatives
Anxiolytics
Diuretics

5. 5
Anti- emetics
AntihistaminesAnti PhenothiazinesMiscellaneous
Cholinergics
Large overlap between the effects produced by
antihistamines, anticholinergics and phenothiazines.

6. 6
Phenothiazines
(Prochlorperazine, Thiethylperazine)
Prochlorperazine is less sedating than some other
phenothiazines but drowsiness still occurs
Also causes hypotension, Parkinsonian side effects
--Betts T et al, Brit. J. Clin. Pharmac, 1991, 32, 455-8,
--Curley JWA, E N T Journal, 1984, 65, 555-560
“The drug which most commonly causes
parkinsonism in general practice is
Prochlorperazine”
--Chaplin S, Geriatric Medicine, 1989, Feb, 13-14

7. 7
Anxiolytics (Tranquilizers)
(Benzodiazepines such as diazepam, Lorazepam)
No effect on the underlying vertigo
Helps patient endure the symptoms by allaying anxiety
Many side effects drowsiness and sedation, dependence
and addiction abuse potential, psychomotor
impairment, memory loss, interactions with alcohol
Harris T, Ear Nose Throat J, 1984, 65, 551-5

8. 8
Diuretics
(e.g. Furosemide, Hydrochlorthiazide)
Used in vertigo and meniere’s disease
Reduce the volume of endolymph by promoting
urine flow and reducing fluid retention.
Use mainly associated with electrolyte imbalance
Ludman H, Brit. Med. J., 1981, 282, 454-457, Harris T, Ear Nose Throat J, 1984, 65, 551-5

9. 9
Cinnarizine, Collin Dollery Therapeutic Drugs, C240-3, Godfraind T et al, Drugs of Today, 1982, XVIII(1), 27-42,
Venkataraman S, Neurosciences Today, 1997, Vol. I, 3&4, 205-6, Norre M E, Crit Rev. Phy. Rehab. Med., 1990, 2,2,101-20
Antihistamines
Cinnarizine, Flunarizine, Cyclizine
Drowsiness and blurred vision (Difficult for patients who
drive or operate machinery)
Delay normal vestibular compensation process
Cinnarizine and Flunarizine act via calcium antagonism,
unspecific action may cause side effects
Weight gain & depression (serotonergic effects)
Extrapyramidal symptoms (dopaminergic effects)
G.I. upset

10. 10
*
SOLVAY
PHARMA INDIA LTD.
Betahistine 8, 16 & 24 mg tablets

11. 11
Betahistine
The original research product of
Solvay
Available Worldover as
Betaserc
®
Serc
®
Vasomotal
®
Urutal
®
Available in India as
Vertin *

12. 12
Data on file
Betahistine
Trusted therapy for more than
41 million
Vertigo patients worldwide

13. 13
BETAHISTINE
CHEMISTRY &
PHARMACOKINETICS

14. 14
Betahistine - Chemistry
Histamine Betahistine
N
N
H
CH
2
CH
2
NH
2
N
CH
2
CH
2
NHCH
3
Histamine analogue, can be given orally
with no histamine like side effects
Van Cauwenberge P B, et al, Acta Otolaryngol, 1997, suppl. 526, 43-6,
Venkataraman S, Neurosciences Today, 1998, II, 1 & 2, 56-8

15. 15
Betahistine : Pharmacokinetics
Oral administration
Rapid and complete absorption
Mean plasma half life :- 3-4 Hrs.
Complete excretion via urine in 24 hours
Very low plasma protein binding
One metabolite (2-aminoethyl pyridine) is
found to be active

16. 16
BETAHISTINE
PHARMACOLOGY
MODE OF ACTION

17. 17
Betahistine : Mode of Action
Vascular Effects Neurological Effects
(in inner ear & brain) (in brain)

18. 18
H3-AUTORECEPTORS … CONTROLLING THE
RELEASE OF HISTAMINE
Adapted Van Cauweneberge PB, Acta Otolaryngol, 1997, suppl. 526, 43-6,
Venkataraman S, Neurosciences Today, 1998, II, 1 & 2, 56-8
H1 H2
H
3

autoreceptor
Histaminergic Neuron

19. 19
Venkataraman S, Neurosciences Today, 1998, II (1 & 2), 56-8
EFFECTS OF BETAHISTINE

20. 20
Betahistine - Vascular Effects
H3 autoreceptors antagonist H1 agonist
Inhibits autoregulation of
histamine release
Venkataraman S, Neurosciences Today, 1998, II (1 & 2), 56-8
Improves cochlear microcirculation
Improves cerebral / vertebrobasilar blood flow

21. 21
Blocks H3 heteroreceptors
Increases release of other
neurotransmitters e.g. serotonin
Regulates firing activity of
vestibular nuclei
Venkataraman S, Neurosciences Today, 1998, II (1 & 2), 56-8,
Biswas A, Ind. J. Otolaryngol H N S, 1997, 49(2), 179-81
Betahistine - Neurological Effects

22. 22
Betahistine : Mode of action
Blocks
H3 heteroreceptors H3 autoreceptors
stimulates release of other
neurotransmitter e.g. serotonin
Stimulates release of histamine
Regulatory effect on
vestibular nuclei
H1 receptor
Symptomatic relief of
vertigo
Prophylactic effect of vertigo
improvement of cochlear & cerebral blood flow
direct stimulatory effect

23. 23
BETAHISTINE
Therapeutic Indications
Vertigo
Meniere’s Syndrome
Dosage Recommendations
24-48 mg /day

24. 24
Betahistine -Tolerance
No sedation
No gastric side effects
No anticholinergic effects
No extrapyramidal side effects
Bradoo RA et al, Ind. J. Otolaryngol HNS, 2000, 52(2), 151-8,
Biswas A, Ind. J. Otolaryngol H N S, 1997, 49(2), 179-81

25. 25
Betahistine: No affinity for
H2 receptors
H2 receptors predominate in stomach
and control gastric secretion
Betahistine has no effect on H2 receptors.
Betahistine is generally free of gastric
side effects
Betahistine, Collin Dollery Therapeutic Drugs, B 62-5
Van Cauwenberge PB, Acta Otolaryngol, 1997, Suppl. 526, 43-6

26. 26
Betahistine
Contraindications - Not known
Precaution / Caution for use
Betahistine, being a histamine analogue,
should be used with caution in patients with
pheochromocytoma, peptic ulcer, bronchial
asthma, concurrent use of antihistamines
Bradoo RA et al, Ind. J. Otolaryngol HNS, 2000, 52(2), 151-8

27. 27
Betahistine No antagonistic effect on
H1 receptors
Antihistamines block H1 receptors in brain, causing
sedation or drowsiness
Betahistine, stimulates H1 receptors
Betahistine, does not slow down vestibular
compensation, unlike antihistamines. Hence is
suitable for use with vestibular habituation therapy.
Kirtane MV, Ind. J. Otolaryngol HNS, 1999, 51(2),27-36

28. 28
Betahistine - Summary
Pharmacokinetics: Rapid and complete absorption
after oral route
Pharmacology: It is a H1 agonist and H3 receptor
antagonist. It increases cochlear and cerebral blood
flow and regulates firing activity of vestibular nuclei.
Dose: 24-48 mg /day
Indication: vertigo, meniere’s syndrome
Contraindications: not known
Precaution for use: pheochromocytoma, peptic ulcer,
bronchial asthma