Dihydergot 2.5mg Tablets

Country: Australia

Language: English

Source: Department of Health (Therapeutic Goods Administration)

Active ingredient:

Dihydroergotamine mesylate

Available from:

Novartis Pharmaceuticals Australia Pty Ltd

ATC code:

N02CA01

Dosage:

2.5mg

Pharmaceutical form:

Tablets

Class:

Medicine Registered

Therapeutic area:

antimigraine preparations

Summary of Product characteristics

1
DIHYDERGOT
®
(DIHYDROERGOTAMINE MESYLATE)
NAME OF THE MEDICINE
Active ingredient
dihydroergotamine mesylate
Chemical name
ergotaman-3’,6’,18-trione,9,10-dihydro-12’-hydroxy-2’-
methyl-5’-(phenylmethyl)-,(5’α)-,monomethanesulfonate
CAS number
6190-39-2
Molecular weight
679.8
Molecular formula
C
34
H
41
N
5
O
8
S
Chemical structure
DESCRIPTION
Dihydroergotamine mesylate is structurally and pharmacologically
related to the other
hydrogenated ergot alkaloids of the peptide type. The mesylate is a
white to slightly
yellowish or grey to pink-tinged powder soluble 0.85% in water, > 2%
in methanol and
approximately 1 % in chloroform.
Dihydergot injection is a clear, colourless solution, pH 3.9-4.9.
EXCIPIENTS
Tablets: tartaric acid, gelatin, magnesium stearate, stearic acid,
talc-purified, starch-maize,
lactose.
Ampoules: ethanol 5 %, glycerol 15 %, and water for injections.
PHARMACOLOGY
PHARMACODYNAMICS
Pharmacotherapeutic group: antimigraine preparations
ATC code: N02CA01
Dihydroergotamine has complex pharmacological effects. It possesses
affinity for both
alpha-adrenergic and serotoninergic receptors with both stimulating
and blocking properties.
2
Dihydergot
exerts
its
effect
in
orthostatic
hypotension
by
selective
constriction
of
capacitance vessels with no significant effect on resistance vessels.
This increase in venous
tone leads to a redistribution of blood, preventing excessive venous
pooling.
In migraine attacks dihydroergotamine acts primarily by compensating
for the decreased
5-HT plasma level. Simulating the effect of 5-HT, it counteracts the
loss of tone of the
extracranial vasculature.
The uterotonic activity of dihydroergotamine is much weaker than that
of ergotamine.
PHARMACOKINETICS
ABSORPTION:
Dihydroergotamine is incompletely and variably absorbed after oral
administration (20 – 50
%). Peak plasma levels are attained in 1-2 hours and are linear over
the range 10 - 30 mg.
The absolute oral bioavailability is low (approx. 1 % when unchanged
drug measured) due
to a 98 % first pass extr