Phendimetrazine

Other names included commercial trade names:

• Adipost, Anorex-SR, Appecon, Bontril, Bontril PDM, Bontril Slow-Release
• Obezine, Phendiet, Plegine, Prelu-2, Statobex, Melfiat

Chemical formula: C₁₂H₁₇NO

Systematic (IUPAC) name: 3,4-Dimethyl-2-phenyl-morpholine

Pharmacology

Phendimetrazine is used clinically in the form of phendimetrazine tartrate.
Approximately 30% of a given dose of phendimetrazine is metabolized into phenmetrazine, which may account for part of its anorectic effect, and probably also influences abuse potential; individuals who metabolise a greater proportion of phendimetrazine into phenmetrazine are more likely to develop problems with dependence and addiction.

Phendimetrazine tartrate is a phenylalkylamine 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.

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 origins of the increased weight loss due to the various drug effects are 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.

Phendimetrazine indications

Bontril® PDM (phendimetrazine tartrate) is indicatedin 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/m2 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 bythe patient's height,inmeters (m), squared. Metric conversions are as follows: pounds ÷ 2.2 = kg; inches x 0.0254 = meters.

Phendimetrazine tartrate is indicated for use as monotherapy only.

Phendimetrazine dosage and administration

Usual Adult Dosage: 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, 1/2 tablet (17.5 mg) per dose may be adequate. Dosage should not exceed 2 tablets three times a day.

Phendimetrazine side effects

Cardiovascular

Palpitation, tachycardia, elevated blood pressure.

Central Nervous System

Overstimulation, restlessness, insomnia, agitation, flushing, tremor, sweating, dizziness, headache, psychotic state, blurring of vision.

Gastrointestinal

Dryness of the mouth, nausea, diarrhea, constipation, stomach pain.

Genitourinary

Urinary frequency, dysuria, changes in libido.

Drug Abuse and Dependence

Controlled Substance
Phendimetrazine tartrate tablets are defined by the Drug Enforcement Administration as a Schedule III 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.

Warnings

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 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.

Precautions

Caution is to be exercised in prescribing phendimetrazine tartrate for patients with even mild hypertension.
Insulin requirements in diabetes mellitus may be altered in association with the use of phendimetrazine and the concomitant dietary regimen.
Phendimetrazine 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.

Usage 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.

Pediatric Patients

Phendimetrazine tartrate is not recommended for use in pediatric patients under 12 years of age.

Overdose

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.

Contraindications

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.

More information

Your pharmacist has more information about phendimetrazine written for health professionals that you may read.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed
Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

How supplied

Three-layered green, white and yellow tablet with “B 35” on the scored side and the letter “V” on the other. Bontril® PDM tablets containing 35 mg of phendimetrazine tartrate are available in bottles of 100 (NDC 0187-0497-01) and 1000 (NDC 0187-0497-02).
Store at 25°C (77°F); excursions permitted to 15°C-30°C (59°F-86°F).
DEA Order Form Required.

Legal status

Phendimetrazine is a drug as potent as amphetamines and is a Schedule III drug under the Convention on Psychotropic Substances. In the United States, phendimetrazine is a Schedule III controlled substance under the Uniform Controlled Substances Act of 1970.

According to the "List of psychotropic substances under international control," phendimetrazine is a Schedule IV controlled substance¹. Phendimetrazine is listed as a Schedule III substance under the U.S. Controlled Substance Act in the 2007 Drug Identification Bible, pg 615 and under Section 11056(b)(6) California Health and Safety Code.

Related images:

*1: List of psychotropic substances under international control

Information are getted from:

http://en.wikipedia.org/wiki/Phendimetrazine

http://www.rxlist.com/phendimetrazine-tartrate-drug.htm

http://www.phendimetrazine.com/

http://www.drugs.com/phendimetrazine.html