Pulmonary Hypertension
Certain centrally-acting weight loss agents that cause release of serotonin
from nerve terminals have been associated with pulmonary hypertension (PPH),
a rare but lethal disease. In premarketing clinical studies, no cases of PPH
have been reported with sibutramine capsules. Because of the low incidence of
this disease in the underlying population, however, it is not known whether
or not MERIDIA (sibutramine hydrochloride monohydrate) may cause this disease.
Seizures
During premarketing testing, seizures were reported in < 0.1% of sibutramine
treated patients. MERIDIA (sibutramine hydrochloride monohydrate) should be used cautiously in patients with a history
of seizures. It should be discontinued in any patient who develops seizures.
Bleeding
There have been reports of bleeding in patients taking sibutramine. While a
causal relationship is unclear, caution is advised in patients predisposed to
bleeding events and those taking concomitant medications known to affect hemostasis
or platelet function.
Gallstones
Weight loss can precipitate or exacerbate gallstone formation.
Renal Impairment
MERIDIA (sibutramine hydrochloride monohydrate) should be used with caution in patients with mild to moderate renal
impairment. MERIDIA (sibutramine hydrochloride monohydrate) should not be used in patients with severe renal impairment,
including those with end stage renal disease on dialysis (see Pharmacokinetics - Special
Populations - Renal Insufficiency).
Hepatic Dysfunction
Patients with severe hepatic dysfunction have not been systematically studied;
MERIDIA (sibutramine hydrochloride monohydrate) should therefore not be used in such patients.
Interference With Cognitive and Motor Performance
Although sibutramine did not affect psychomotor or cognitive performance in
healthy volunteers, any CNS active drug has the potential to impair judgment,
thinking or motor skills.
Information For Patients
Physicians should instruct their patients to read the Medication Guide before
starting therapy with MERIDIA (sibutramine hydrochloride monohydrate) and to reread it each time the prescription is
renewed.
Physicians should also discuss with their patients any part of the package
insert that is relevant to them. In particular, the importance of keeping appointments
for follow-up visits should be emphasized.
Patients should be advised to notify their physician if they develop a rash,
hives, or other allergic reactions.
Patients should be advised to inform their physicians if they are taking, or
plan to take, any prescription or over-the-counter drugs, especially weight-reducing
agents, decongestants, antidepressants, cough suppressants, lithium, dihydroergotamine, sumatriptan (Imitrex®), or tryptophan, since there is a potential for interactions.
Patients should be reminded of the importance of having their blood pressure
and pulse monitored at regular intervals.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenicity
Sibutramine was administered in the diet to mice (1.25, 5 or 20 mg/kg/day)
and rats (1, 3, or 9 mg/kg/day) for two years generating combined maximum plasma
AUC's of the two major active metabolites equivalent to 0.4 and 16 times, respectively,
those following a daily human dose of 15 mg. There was no evidence of carcinogenicity
in mice or in female rats. In male rats there was a higher incidence of benign
tumors of the testicular interstitial cells; such tumors are commonly seen in
rats and are hormonally mediated. The relevance of these tumors to humans is
not known.
Mutagenicity
Sibutramine was not mutagenic in the Ames test, in vitro Chinese hamster
V79 cell mutation assay, in vitro clastogenicity assay in human lymphocytes
or micronucleus assay in mice. Its two major active metabolites were found to
have equivocal bacterial mutagenic activity in the Ames test. However, both
metabolites gave consistently negative results in the in vitro Chinese
hamster V79 cell mutation assay, in vitro clastogenicity assay in human
lymphocytes, in vitro DNA-repair assay in HeLa cells, micronucleus assay
in mice and in vivo unscheduled DNA-synthesis assay in rat hepatocytes.
Impairment of Fertility
In rats, there were no effects on fertility at doses generating combined plasma
AUC's of the two major active metabolites up to 32 times those following a human
dose of 15 mg. At 13 times the human combined AUC, there was maternal toxicity,
and the dams' nest-building behavior was impaired, leading to a higher incidence
of perinatal mortality; there was no effect at approximately 4 times the human
combined AUC.
Pregnancy
Teratogenic Effects
Pregnancy Category C
Radiolabeled studies in animals indicated that tissue distribution was unaffected
by pregnancy, with relatively low transfer to the fetus. In rats, there was
no evidence of teratogenicity at doses of 1, 3, o r 10 mg/kg/day generating
combined plasma AUC's of the two major active metabolites up to approximately
32 times those following the human dose of 15 mg. In rabbits dosed at 3, 15,
or 75 mg/kg/day, plasma AUC's greater than approximately 5 times those following
the human dose of 15 mg caused maternal toxicity. At markedly toxic doses, Dutch
Belted rabbits had a slightly higher than control incidence of pups with a broad
short snout, short rounded pinnae, short tail and, in so me, shorter thickened
long bones in the limbs; at comparably high doses in New Zealand White rabbits,
one study showed a slightly higher than control incidence of pups with cardiovascular
anomalies while a second study showed a lower incidence than in the control
group.
No adequate and well controlled studies with sibutramine have been conducted
in pregnant women. The use of MERIDIA (sibutramine hydrochloride monohydrate) during pregnancy is not recommended. Women
of childbearing potential should employ adequate contraception while taking
MERIDIA (sibutramine hydrochloride monohydrate) . Patients should be advised to n otify their physician if they become
pregnant or intend to become p regnant while taking MERIDIA (sibutramine hydrochloride monohydrate) .
Nursing Mothers
It is not known whether sibutramine or its metabolites are excreted in human
milk. MERIDIA (sibutramine hydrochloride monohydrate) is not recommended for use in nursing mothers. Patients should
be advised to notify their physician if they are breast-feeding.
Pediatric Use
The efficacy of sibutramine in adolescents who are obese has not been adequately
studied.
Sibutramine's mechanism of action inhibiting the reuptake of serotonin and
norepinephrine is similar to the mechanism of action of some antidepressants.
Pooled analyses of short-term placebo-controlled trials of antidepressants in
children and adolescents with major depressive disorder (MD D), obsessive compulsive
disorder (OCD), and other psychiatric disorders have revealed a greater risk
of adverse events representing suicidal behavior or thinking during the first
few months of treatment in those receiving antidepressants. The average risk
of such events in patients receiving antidepressants was 4%, twice the placebo
risk of 2%.
No placebo-controlled trials of sibutramine have been conducted in children
or adolescents with MDD, OCD, or other psychiatric disorders. In a study of
adole scents with obesity in which 368 patients were treated with sibutramine
and 130 patients with placebo, one patient in the sibutr amine group and one
patient in the placebo group attempted suicide. Suicidal ideation was reported
by 2 sibutramine-treated patients and none of the placebo patients. It is unknown
if sibutramine increases the risk of suicidal behavior or thinking in pediatric
patients.
The data are inadequate to recommend the use of sibutramine for the treatment
of obesity in pediatric patients.
Geriatric Use
Clinical studies of sibutramine did not include sufficient numbers of patients
over 65 years of age. Sibutramine is contraindicated in this group of patients
(see CONTRAINDICATIONS). Pharmacokinetics in elderly patients are discussed
in “CLINICAL PHARMACOLOGY.”
Last reviewed on RxList: 1/31/2011
This monograph has been modified to include the generic and brand name in many instances.