IONAMIN Capsules are indicated only as short-term
monotherapy for the management of exogenous obesity. The safety and efficacy of
combination therapy with phentermine and any other drug products for weight
loss, including selective serotonin reuptake inhibitors (e.g., fluoxetine,
sertraline, fluvoxamine, paroxetine), have not been established. Therefore, the
coadministration of these drug products for weight loss is not recommended.
Primary Pulmonary Hypertension (PPH) – a rare,
frequently fatal disease of the lungs – has been reported to occur in patients
receiving a combination of phentermine with fenfluramine or dexfenfluramine.
The possibility of an association between PPH and the use of phentermine alone
cannot be ruled out. The initial symptom of PPH is usually dyspnea. Other
initial symptoms include: angina pectoris, syncope, or lower extremity edema.
Patients should be advised to report immediately any deterioration in exercise
tolerance. Treatment should be discontinued in patients who develop new,
unexplained symptoms of dyspnea, angina pectoris, syncope, or lower extremity
Valvular Heart Disease
Serious regurgitant cardiac valvular disease,
primarily affecting the mitral, aortic and/or tricuspid valves, has been
reported in otherwise healthy persons who had taken a combination of
phentermine with fenfluramine or dexfenfluramine for weight loss. The etiology
of these valvulopathies has not been established and their course in
individuals after the drugs are stopped is not known.
If tolerance to the “anorectic” effect develops, the
recommended dose should not be exceeded in an attempt to increase the effect:
rather, the drug should be discontinued.
IONAMIN may impair the ability of the patient to engage
in potentially hazardous activities such as operating machinery or driving a
motor vehicle; the patient should therefore be cautioned accordingly.
When using CNS active agents, consideration must always
be given to the possibility of adverse interactions with alcohol.
IONAMIN is related chemically and pharmacologically to
amphetamine (d- and dl-amphetamine) and other stimulant drugs that have been
extensively abused. The possibility of abuse of IONAMIN should be kept in mind
when evaluating the desirability of including a drug as part of a weight
reduction program. Abuse of amphetamine (d- and dl-amphetamine) and related
drugs may be associated with intense psychological dependence and severe social
dysfunction. There are reports of patients who have increased the dosage of
some of these drugs to many times that recommended. Abrupt cessation following
prolonged high dosage administration results in extreme fatigue and mental
depression; changes are also noted on the sleep EEG. Manifestations of chronic
intoxication with anorectic drugs include severe dermatoses, marked insomnia,
irritability, hyperactivity, and personality changes. The most severe
manifestation of chronic intoxications is psychosis, often clinically
indistinguishable from schizophrenia.
Usage in Pregnancy
Safe use in pregnancy has not been established. Use of
IONAMIN by women who are or may become pregnant requires that the potential
benefit be weighed against the possible hazard to mother and infant.
IONAMIN® Capsules (phentermine resin) are not recommended
for use in pediatric patients under 16 years of age.