- Ondansetron
- 5-HT3
receptor blocker
- minimal effects on
dopamine, histamine, adrenergic
or cholinergic receptor activity
- very effective for prevention of nausea and vomiting caused by
chemotherapy or surgery. -- major role in
management of severe nausea and vomiting
due to anticancer drugs
- Clinical Use:
- Dosage: 4-8 mg IV
(administered over 2-5 minutes
just before anesthesia induction)
- Highly effective in
reducing postoperative
nausea/vomiting incidents --
particularly in susceptible
patient groups:
- ambulatory
gynecologic surgery
- middle ear
surgery
- Oral or IV reduces
incidence of postoperative
vomiting and preadolescent
children undergoing:
- ambulatory
surgery, e.g.
tonsillectomy, strabismus
surgery
- Ondansetron: effective
both for prophylaxis and
treatment of postoperative
nausea/vomiting
- decreases
incidents & intensity
of postoperative nausea
& vomiting -- but
does not totally
eliminate this problem
- Major advance:
reduced side effects
compared to previously
used antiemetic drugs
such as:
- phenothiazines,
antihistamines,
butyrophenones
- Propofol for
induction and maintenance of
anesthesia may be as effective as
ondansetron in
reducing/preventing postoperative
nausea & vomiting
- Side Effects:
- Surgical patients:
- 3%
increased liver
transaminase enzyme
levels
- 3%
headache
- No sedation,
hypotension, dysphoria,
extrapyramidal reactions -- side
effects associated with other
antiemetic drugs
- Tropisetron:
- 5-HT3 receptor
blocker
- Effective in managing
symptoms induced by carcinoid syndrome--
also some gastrokinetic characteristics
- Effective in preventing
chemotherapy/radiotherapy-induced emesis
- Effective in preventing
postoperative nausea/vomiting when
administered before general anesthetic
induction
- Granisetron
- More selective 5-HT3
receptor blocker compared to ondansetron
- Clinical Use:
- Effective in the
chemotherapy-induced emesis
prevention
- Effective in
preventing postoperative
nausea/vomiting
- Elimination half-life:
nine hours, compared to about three hours
for ondansetron: suggesting less frequent
dosing with granisetron.
- Significantly higher
cost-- could limit clinical use
- Dolasetron:
- Highly
potent/selective 5-HT3
receptor blocker
- Clinical Use:
- Effective in
preventing chemotherapy-induced
nausea/vomiting
- Effective in
reducing likelihood of
postoperative nausea &
vomiting
- Antiemetic effect
due to long-acting, active
metabolite (hydrodolasetron;
elimination half-life =
approximately 8 hours)
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