Ivermectin Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R61:Kann das Kind im Mutterleib sch?digen.
R25:Giftig beim Verschlucken.
R36:Reizt die Augen.
R36/38:Reizt die Augen und die Haut.
R22:Gesundheitssch?dlich beim Verschlucken.
S-S?tze Betriebsanweisung:
S53:Exposition vermeiden - vor Gebrauch besondere Anweisungen einholen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn m?glich, dieses Etikett vorzeigen).
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
Beschreibung
Ivermectin is an antiparasitic agent effective in the treatment of onchocerciasis, or "river
blindness". Since ivermectin acts to prevent the adult worm from producing microfilariae,
it needs to be administered only once or twice a year.
Chemische Eigenschaften
Crystalline Solid
synthetische
The synthesis of ivermectin involves the hydrogenation
of the naturally occurring avermectin B1 (abamectin) at
the double bond linking C-22 and C-23. This results in a
mixture of two homologues, 22, 23-dihydroavermectin B1a
(H2B1a) and 22, 23-dihydroavermectin B1b (H2 B1b). The
a- and b- nomenclature refers to the presence on C-25, of
either a secondary butyl side chain or an isopropyl group,
respectively. The biological activities of H2B1a and H2B1b
are similar. Large-scale separation of the two homologues
is not practical, and, hence, ivermectin is marketed as a
mixture of H2 B1a (>80%) and H2 B1b (<20%).
Indications
Ivermectin (Mectizan) acts on parasite-specific inhibitory
glutamate-gated chloride channels that are
phylogenetically related to vertebrate GABA-gated
chloride channels. Ivermectin causes hyperpolarization
of the parasite cell membrane and muscle paralysis.At
higher doses it can potentiate GABA-gated chloride
channels. It does not cross the blood-brain barrier and
therefore has no paralytic action in mammals, since
GABA-regulated transmission occurs only in the central
nervous system (CNS). Ivermectin is administered
by the oral and subcutaneous routes. It is rapidly absorbed.
Most of the drug is excreted unaltered in the feces.
The half-life is approximately 12 hours.
Antimicrobial activity
It is also active against O. volvulus and other filarial
worms, but the effect is chiefly directed against the larval
forms (microfilariae). Uniquely among anthelmintic agents
it exhibits activity against some ectoparasites, including
Sarcoptes scabiei.
Biologische Aktivit?t
Positive allosteric modulator of the α 7 neuronal nicotinic acetylcholine receptor and the purinergic P2X 4 receptor. Antihelmintic. Also modulates glutamate- and GABA-activated chloride channels. Potentiates glycine-gated currents at low concentrations (30 nM).
Clinical Use
Onchocerciasis
Non-disseminated strongyloidiasis
Lymphatic filariasis (in combination with albendazole)
Scabies
If the patient is harboring
Asc. lumbricoides, the worms will be passed in the feces. Head lice will also be killed, which is very much welcomed by the treated patients. Ivermectin has been widely used in the veterinary field, where use is also made of its effect on ectoparasites.
Nebenwirkungen
In the treatment of onchocerciasis mild Mazzotti-type reactions
occur, with occasional neurological problems. Although it is
highly effective against L. loa, care must be taken to avoid treating
patients with high microfilarial counts: there is one report
of a patient with a concomitant L. loa infection who died when
treated for onchocerciasis. Mild gastrointestinal and nervous system
signs may occur following treatment for strongyloidiasis.
Stoffwechsel
Ivermectin is rapidly absorbed, is bound to a great extent to plasma protein, and is excreted in the
urine or feces either unchanged or as the 3′-O-demethyl-22,23-dihydroavermectin B1
α or as the
dihydroavermectin B1
α monosaccharide. The absorption of IVM is significantly affected by the
presence of alcohol. Administration of IVM as an alcoholic solution may result in as much as a
100% increase in absorption.
Ivermectin Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
