Phendimetrazine Tartrate
FDA Label NDC 61502-922

PHENDIMETRAZINE
TARTRATE TABLETS,
USP 35 mg, CIII
Rx Only

Phendimetrazine tartrate, as the dextro isomer, has the chemical name of (2S,3S)-3,4-Dimethyl-2-
phenylmorpholine L-(+)- tartrate (1:1).
The structural formula is:
C H NO•C H O M.W. 34 1.36
Phendimetrazine tartrate is a white, odorless crystalline powder. It is freely soluble in water; sparingly
soluble in warm alcohol, insoluble in chloroform, acetone, ether and benzene.
Each white tablet, for oral administration, contains 35 mg of phendimetrazine tartrate. In addition, the
following inactive ingredients are present: Colloidal Silicon Dioxide, Lactose Monohydrate,
Magnesium Stearate, Microcrystalline Cellulose 102 and Sodium Starch Glycolate. The yellow tablet
also contains FD&C Yellow # 5 Aluminum Lake (15-17%). The blue tablet also contains FD&C Blue #
1 Aluminum Lake (11-13%).

Phendimetrazine tartrate is a sympathomimetic amine with pharmacological 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 these phenomena have been looked for.
Drugs of this class used in obesity are commonly known as “anorectics” or “anorexigenics”. It has not
been established, however, 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.
12 17 4 6 6
Adult obese subjects instructed in dietary management and treated with anorectic drugs, lose more
weight on the average than those treated with placebo and diet, as determined in relatively short term
clinical trials.
The magnitude of increased weight loss of drug-treated patients over placebo-treated patients is only a
fraction of a pound a week. The rate of weight loss is greatest in the first weeks of therapy for both
drug and placebo subjects and tends to decrease in succeeding weeks. The possible origin of the
increased weight loss due to the various drug effects is not established. The amount of weight loss
associated with the use of an anorectic drug varies from trial to trial, and the increased weight loss
appears to be related in part to variables other than the drug prescribed, such as the physician
investigator, the population treated, and the diet prescribed. Studies do not permit conclusions as to the
relative importance of the drug and non-drug factors on weight loss.
The natural history of obesity is measured in years, whereas the studies cited are restricted to a few
weeks duration; thus, the total impact of drug-induced weight loss over that of diet alone must be
considered clinically limited.
The major route of elimination is via the kidneys where most of the drug and metabolites are excreted.
Some of the drug is metabolized to phendimetrazine and phendimetrazine-N-oxide. The average halflife
of elimination when studied under controlled conditions is about 3.7 hours for both the extendedrelease
and immediate release forms. The absorption half-life of the drug from the immediate release
35 mg phendimetrazine tablets is appreciably more rapid than the absorption rate of the drug from the
extended-release formulation.

Phendimetrazine tartrate is indicated in the management of exogenous obesity as a short term adjunct (a
few weeks) in a regimen of weight reduction based on caloric restriction in patients with an initial body
mass index (BMI) of 30 kg/m or higher who have not responded to appropriate weight reducing
regimen (diet and/or exercise) alone. Below is a chart of Body Mass Index (BMI) based on various
heights and weights. BMI is calculated by taking the patient’s weight, in kilograms (kg), divided by the
patient’s height, in meters (m), squared. Metric conversions are as follows: pounds ÷ 2.2 = kg; inches x
0.0254 = meters.
BODY MASS INDEX (BMI), kg/m Height (feet, inches )
Weight(pounds) 5’0” 5’3” 5’6” 5’9” 6’0” 6’3”
140 27 25 23 21 19 18
150 29 27 24 22 20 19
160 31 28 26 24 22 20
170 33 30 28 25 23 21
180 35 32 29 27 25 23
190 37 34 31 28 26 24
200 39 36 32 30 27 25
210 41 37 34 31 29 26
220 43 39 36 33 30 28
230 45 41 37 34 31 29
240 47 43 39 36 33 30
250 49 44 40 37 34 31
Phendimetrazine tartrate is indicated for use as monotherapy only.

Known hypersensitivity or idiosyncratic reactions to sympathomimetics.
Advanced arteriosclerosis, symptomatic cardiovascular disease, moderate and severe hypertension,
hyperthyroidism, and glaucoma.
Highly nervous or agitated patients.
Patients with a history of drug abuse.
Patients taking other CNS stimulants, including monoamine oxidase inhibitors.

Phendimetrazine tartrate should not be us ed in combination with other anorectic agents ,
including pres cribed drugs , over-the-counter preparations and herbal products .
In a case-control epidemiological study, the use of anorectic agents, including phendimetrazine tartrate,
was associated with an increased risk of developing pulmonary hypertension, a rare, but often fatal
disorder. The use of anorectic agents for longer than three months was associated with a 23-fold
increase in the risk of developing pulmonary hypertension. Increased risk of pulmonary hypertension
with repeated courses of therapy cannot be excluded.
The onset or aggravation of exertional dyspnea, or unexplained symptoms of angina pectoris, syncope,
or lower extremity edema suggest the possibility of occurrence of pulmonary hypertension. Under
these circumstances, phendimetrazine tartrate should be immediately discontinued, and the patient should
be evaluated for the possible presence of pulmonary hypertension.
Valvular heart dis eas e as s ociated with the us e of s ome anorectic agents such as fenfluramine and
dexfenfluramine has been reported. Pos s ible contributing factors include use for extended
periods of time, higher than recommended dos e, and/or us e in combination with other anorectic
drugs . However, no cas es of this valvulopathy have been reported when phendimetrazine tartrate
has been us ed alone.
The potential risk of possible serious adverse effects such as valvular heart disease and pulmonary
hypertension should be assessed carefully against the potential benefit of weight loss. Baseline cardiac
evaluation should be considered to detect pre-existing valvular heart diseases or pulmonary
hypertension prior to initiation of phendimetrazine treatment. Phendimetrazine tartrate is not
recommended in patients with known heart murmur or valvular heart disease. Echocardiogram during
and after treatment could be useful for detecting any valvular disorders which may occur. To limit
unwarranted exposure and risks, treatment with phendimetrazine tartrate should be continued only if the
patient has satisfactory weight loss within the first 4 weeks of treatment (i.e., weight loss of at least 4
pounds, or as determined by the physician and patient).
Tolerance to the anorectic effect of phendimetrazine develops within a few weeks. When this occurs,
its use should be discontinued; the maximum recommended dose should not be exceeded.
Use of phendimetrazine tartrate within 14 days following the administration of monoamine oxidase
inhibitors may result in a hypertensive crisis.
Abrupt cessation of administration following prolonged high dosage results in extreme fatigue and
depression. Because of the effect on the central nervous system, phendimetrazine tartrate 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.
Phendimetrazine tartrate is not recommended for patients who used any anorectic agents within the prior
year.

Caution is to be exercised in prescribing phendimetrazine for patients with even mild hypertension.
Insulin requirements in diabetes mellitus may be altered in association with the use of phendimetrazine
tartrate and the concomitant dietary regimen.
Phendimetrazine tartrate may decrease the hypotensive effect of guanethidine. The least amount feasible
should be prescribed or dispensed at one time in order to minimize the possibility of overdosage.
Only yellow tablet contains FD&C Yellow No. 5 (tartrazine) which may cause allergic-type reactions
(including bronchial asthma) in certain susceptible persons. Although the overall incidence of FD&C
Yellow No. 5 (tartrazine) sensitivity in the general population is low, it is frequently seen in patients
who also have aspirin hypersensitivity.

Efficacy of phendimetrazine tartrate with other anorectic agents has not been studied and the combined
use may have the potential for serious cardiac problems.
Carcinogenes is , Mutagenes is , Impairment of Fertility:
Studies with Phendimetrazine Tartrate have not been performed to evaluate carcinogenic potential,
mutagenic potential or effects on fertility.
Pregnancy: Pregnancy Category C:
Animal reproduction studies have not been conducted with phendimetrazine tartrate. It is also not known
whether phendimetrazine tartrate can cause fetal harm when administered to a pregnant woman or can
affect reproduction capacity.
Us age in Pregnancy:
Safe use in pregnancy has not been established. Until more information is available, phendimetrazine
tartrate should not be taken by women who are or may become pregnant unless, in the opinion of the
physician, the potential benefits outweigh the possible hazards.
Nurs ing Mothers :
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human
milk, phendimetrazine tartrate should not be taken by women who are nursing unless, in the opinion of
the physician, the potential benefits outweigh the possible hazards.
Pediatric Us e:
Safety and effectiveness in pediatric patients have not been established.

Cardiovas cular: Palpitations, tachycardia, elevated blood pressure, ischemic events.
Valvular heart disease associated with the use of some anorectic agents such as fenfluramine and
dexfenfluramine, both independently and especially when used in combination with other anorectic
drugs, have been reported. However, no case of this valvulopathy has been reported when
phendimetrazine tartrate has been used alone.
Central Nervous Sys tem:
Overstimulation, restlessness, insomnia, agitation, flushing, tremor, sweating, dizziness, headache,
psychotic state, blurring of vision.
Gas trointes tinal:
Dryness of the mouth, nausea, diarrhea, constipation, stomach pain.
Genitourinary:
Urinary frequency, dysuria, changes in libido.

Controlled Substance:
Phendimetrazine tartrate tablets are a Schedule lll controlled substance.
Dependence:
Phendimetrazine tartrate is related chemically and pharmacologically to the amphetamines.
Amphetamines and related stimulant drugs have been extensively abused, and the possibility of abuse of
phendimetrazine 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 from schizophrenia.

Acute overdosage with phendimetrazine tartrate may manifest itself by the following signs and
symptoms: unusual restlessness, confusion, belligerence, hallucinations, and 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. Poisoning may result in convulsions, coma, and death.
The management of overdosage is largely symptomatic. It includes sedation with a barbiturate. If
hypertension is marked, the use of a nitrate or rapid-acting alpha receptor-blocking agent should be
considered. Experience with hemodialysis or peritoneal dialysis is inadequate to permit
recommendations for its use.

Usual Adult Dos age: 1 tablet (35 mg) twice a day or three times a day one hour before meals.
Dosage should be individualized to obtain an adequate response with the lowest effective dosage. In
some cases, ½ tablet (17.5 mg) per dose may be adequate. Dosage should not exceed 2 tablets three
times a day.

Phendimetrazine Tartrate Tablets , USP 35 mg are available as
White, round, biconvex tablets debossed “K” above bisect “45” on one side and plain on the other side.
Bottles of 30 NDC 10702-045-03
Bottles of 100 NDC 10702-045-01
Bottles of 1000 NDC 10702-045-10
Yellow, round, biconvex tablets debossed “K” above bisect “77” on one side and plain on the other side.
Bottles of 30 NDC 10702-077-03
Bottles of 100 NDC 10702-077-01
Bottles of 1000 NDC 10702-077-10
Blue, round, biconvex tablets debossed “K” above bisect “78” on one side and plain on the other side.
Bottles of 30 NDC 10702-078-03
Bottles of 100 NDC 10702-078-01
Bottles of 1000 NDC 10702-078-10
Store at 20° to 25°C (68° to 77°F); excursions permitted between 15° to 30°C (59° to 86°F) [See USP
Controlled Room Temperature].
DEA Order Form Required.
Manufactured by:
KVK-TECH, INC.
110 Terry Drive Suite 200
Newtown, PA 18940-1850
Item ID # 006080/05 09/10