SEROTONIN RECEPTORS Flashcards
There are currently _____serontonin
14 serotonin receptor subtypes
All except ______are GS protein
5-HT 3 receptors,
5 HT3 receptors subtype is located in both the
central and peripheral nervous systems
In CNS highest concentration found in
Chemoreceptor ciliary Tract
Selective 5-HT3 receptor antagonists
Selectively antagonize the 5-HT3 receptor subtype
Selective 5-HT3 receptor antagonists
Dolansetron
Granisetron
ondansetron equally efficacious at equivalent doses
Dolansetron
Granisetron
ondansetron
both available in oral and IV
Only available in IV
PALONOSETRON
MOA of 5-HT3 receptor antagnosis
Selectively bind and inhibit 5-HT 3 receipts blocking the binding of serotonin at this receptor subtype and subsequent N/V
Peripherally and centrally
These agents are not effective in
motion induced N/V from vestibular stimulation
UNIQUE long half life
PALONOSETRON (ALOXI) 40 hours
PALONOSETRON(ALOXI)
Takes long ot work
Most common side effects
Headache (MOST COMMON)
Dose dependent QT prolongation
New warning for 5-HT3 receptor antagonists.
The development of serotonin syndrome reported with 5-HT3 receptors antagonist
New warning for 5-HT3 receptor antagonists.
The development of serotonin syndrome reported with 5-HT3 receptors antagonist.
reported with repeated administration, cases were fatal
The prototypical selective 5-HT3 receptor antagonists
ONdansetron 4-8mg IVP 2-4 minuts
Ondansetron dose < or equal to 40kg
0.1mg/kg over 2-5 minuts for prophylaxis
Ondansetron dose > or equal to 40kg
4mg IVP over 2-5 minutes for phorphylaxis
Patients with severe hepatic impairment
Total dose of 8 mg
Drug-drug interactions
APOMORPHINE : profound hypotension and LOC can occur and for this reason ONDANSETRON is CONTRAINDICATED with concomittant use.
DOLASETRON metabolism
***KNOW ACTIVE METABOLITE
Active, not a prodrug completely metabolized by plasma carbonyl reductase enzyme to an active metabolite.
HYDRODOLASETRON
PONV prophylaxis DOLASETRON
100mg PO 2 hours before surgery
12.5 mg IV 15 mins before surgery
15 min before cessation
PONV treatment ***(compare tx vs prophylaxis)
12.5 mg IV as soon as NV presents
PALONOSETRON (ALOXI)
good drug, last longer
DO NOT USE BECAUSE OF “cost” 200-300 a dose
