Phentermine is a sympathomimetic
amine with pharmacologic activity similar to the prototype drugs of this
class used in obesity, the amphetamines. Actions include central nervous
system stimulation and elevation of blood pressure. Tachyphylaxis and tolerance
have been demonstrated with all drugs of this class in which the sephenomena
have been looked for. Phentermine used in obesity are commonly known as
anorecticsor anorexigenics It has not been established that the action
of such drugs in treating obesity is primarily one of appetite suppression.
Other central nervous system actions, or metabolic effects, may be involved,
for example. Adult obese subjects instructed in dietary management and
treated with anorecticdrugs lose more weight on the average than those
treated with placebo and diet, as determined in relatively short-term clinical
Oral Phentermine hydrochloride
is used as an appetite suppressant used for short-term treatment of exogenous
obesity. Phentermine is used in conjunction with an overall diet plan to
Phentermine: How it Works
Phentermine works by stimulating
a gland, called the hypothalamus, and affecting certain neurotransmitters
to decrease appetite. Because Phentermine hydrochloride is similar chemically
to amphetamines, it has the potential for psychological dependency. Phentermine
should be used with caution.
Phentermine: How to Take
Phentermine is best taken
on an empty stomach one half-hour before breakfast. Because Phentermine
may cause sleeplessness, avoid taking a dose late in the day. Take Phentermine
as prescribed. Do not take it more often or longer than directed.
Phentermine: Side Effects
Dry mouth, sleeplessness,
irritability, stomach upset or constipation may occur the first few days
as your body adjusts to Phentermine. If these effects persist or become
bothersome, inform your doctor.
Adults Under 60: Capsules:
Phentermine 15 to 37.5 mg every morning before breakfast or 1 to 2 hours
after breakfast. Tablets: Phentermine 15 to 37.5 mg every morning before
breakfast or 1 to 2 hours after breakfast. Alternatively, take Phentermine
15 to 37.5 mg in divided doses one-half hour before meals.
Adults 60 and Over: Reduced
Phentermine dosage may be necessary. Consult your physician. Infants and
Children: Use is not recommended.
Maximum Dosage Recommendations:
Do not exceed the recommended Phentermine doses, unless deemed necessary
by your doctor.
If You Miss a Dose: Take
as soon as possible. If close to the next dose, skip and take the next
dose. Do not double the dose.
Tell your doctor your complete
medical history especially if you have high blood pressure, an over-active
thyroid, glaucoma, diabetes or emotional problems. Consult with your doctor
if you think you are pregnant or before breast-feeding. Alcohol can increase
unwanted side effects of dizziness. Limit alcohol use. Phentermine is not
recommended for use in children. Consult your doctor or pharmacist for
Phentermine: Drug Interactions
Inform your doctor about
all the medicines you use, (prescription and nonprescription) especially
if you take high blood pressure medicine or MAO inhibitors (e.g., furazolidone,
phenelzine, selegiline, tranylcypromine) or any other weight loss medicine.
Decongestants are commonly found in over-the-counter cough and cold medicine.
Phentermine: Drug Abuse
Phentermine is related chemically
and pharmacologically to the amphetamines. Amphetamines and related stimulant
drugs have been extensively abused, and the possibility of abuse of Phentermine
should be kept in mind when evaluating the desirability of including a
drug as part of a weight reduction program.
Abuse of amphetamines and
related drugs may be associated with intense psychological dependence and
severe social dysfunction. There are reports of patients who have increased
the dosage 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
Tolerance to the anorectic
effect usually develops within a few weeks. When this occurs, the recommended
Phentermine dose should not be exceeded in an attempt to increase the effect;
rather, the drug should be discontinued. Phentermine hydrochloride 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.
Usage in Pregnancy: Safe
use in pregnancy has not been established. Use of Phentermine hydrochloride
by women who are or who may become pregnant, and those in the first trimester
of pregnancy, requires that the potential benefit be weighed against the
possible hazard to mother and infant.
Usage in Children: Phentermine
hydrochloride is not recommended for use in children under 12 years of
Manifestations of acute
overdosage with Phentermine include restlessness, tremor, hyperreflexia,
rapid respiration, confusion, assaultiveness, hallucinations, panic states.
Fatigue and depression usually follow the central stimulation. Cardiovascular
effects include arrhythmias, hypertension or hypotension, and circulatory
collapse. Gastrointestinal symptoms include nausea, vomiting, diarrhea,
and abdominal cramps. Fatal poisoning usually terminates in convulsions
Management of acute Phentermine
intoxication is largely symptomatic and includes lavage and sedation with
a barbiturate. Experience with hemodialysis or peritoneal dialysis is inadequate
to permit recommendations in this regard. Acidification of the urine increases
Phentermine excretion. Intravenous phentolamine (Regitine) has been suggested
for possible acute, severe hypertension, if this complicates Phentermine
Phentermine appetite suppressants
are not a substitute for proper diet. For maximum effects, this must be
used in conjunction with a diet and exercise program. Do not share Phentermine
Store Phentermine at room
temperature away from sunlight and moisture. Keep this and all medications
out of the reach of children