Benzphetamine

The following have been associated with the use of benzphetamine hydrochloride:

Cardiovascular

Palpitation, tachycardia, elevation of blood pressure.

There have been isolated reports of cardiomyopathy and ischemic cardiac events associated with chronic amphetamine use.

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 cases of this valvulopathy have been reported when DIDREX Tablets have been used alone.

CNS

Overstimulation, restlessness, dizziness, insomnia, tremor, sweating, headache; rarely, psychotic episodes at recommended doses; depression following withdrawal of the drug.

Gastrointestinal

Dryness of the mouth, unpleasant taste, nausea, diarrhea, other gastrointestinal disturbances.

Allergic

Urticaria and other allergic reactions involving the skin.

Endocrine

Changes in libido.

Manifestations Of Overdosage

Acute overdosage with amphetamines may result in restlessness, tremor, tachypnea, confusion, assaultiveness 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. Hyperpyrexia and rhabdomyolysis have been reported and can lead to a number of associated complications. Fatal poisoning is usually preceded by convulsions and coma.

Treatment Of Overdosage

(See WARNINGS) — Information concerning the effects of overdosage with DIDREX Tablets is extremely limited. The following is based on experience with other anorexiants.

Management of acute amphetamine intoxication is largely symptomatic and includes sedation with a barbiturate. If hypertension is marked, the use of a nitrite or rapidly acting alpha receptor blocking agent should be considered. Experience with hemodialysis or peritoneal dialysis is inadequate to permit recommendations in this regard.

Acidification of the urine increases amphetamine excretion.

The oral LD50 is 174 mg/kg in mice and 104 mg/kg in rats. The intraperitoneal LD50 in mice is 153 mg/kg.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of benzphetamine can be fatal.

Overdose symptoms may include confusion, panic, feeling hostile or aggressive, nausea, vomiting, diarrhea, stomach cramps, fever, muscle pain or weakness, dark colored urine, irregular heartbeat, weak pulse, slow breathing, feeling light-headed, seizure, or fainting.

Usual Adult Dose for Obesity:

Initial dose: 25 to 50 mg orally once a day in the mid-morning or mid-afternoon, according to the patient's eating habits.

Maintenance dose: 25 to 50 mg orally one to three times a day; dose or frequency should be individualized based on the patient's needs and response.

Comments:
-It may be desirable to avoid late afternoon administration in some patients.
-Continue treatment 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) to limit unwarranted exposure and risks.
-This drug is indicated for use as monotherapy only.

Use: Management of exogenous obesity as a short term (a few weeks) adjunct in a regimen of weight reduction based on caloric restriction in patients with an initial BMI of 30 kg/m2 or higher who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone.

Usual Pediatric Dose for Obesity:

Initial dose (Age 12 to 17 years): 25 to 50 mg orally once a day in the mid-morning or mid-afternoon, according to the patient's eating habits.

Maintenance dose (Age 12 to 17 years): 25 to 50 mg orally one to three times a day; dose or frequency should be individualized based on the patient's needs and response.

Comments:
-Use of this drug is not recommended in children under 12 years.
-It may be desirable to avoid late afternoon administration in some patients.
-Continue treatment 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) to limit unwarranted exposure and risks.
-This drug is indicated for use as monotherapy only.

Use: Management of exogenous obesity as a short term (a few weeks) adjunct in a regimen of weight reduction based on caloric restriction in patients with an initial BMI of 30 kg/m2 or higher who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone.

For all patients taking benzphetamine:

• If you have an allergy to benzphetamine or any other part of this medicine.
• If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
• If you have any of these health problems: Blood vessel disease, glaucoma, high blood pressure, nervous, anxious, or tense state, overactive thyroid disease, or structure problems of the heart or other heart problems.
• If you have ever abused drugs.
• If you are pregnant or may be pregnant. Do not take benzphetamine if you are pregnant.
• If you are breast-feeding. Do not breast-feed while you take this medicine.
• If you have taken certain drugs used for low mood (depression) like isocarboxazid, phenelzine, or tranylcypromine or drugs used for Parkinson's disease like selegiline or rasagiline in the last 14 days. Taking benzphetamine within 14 days of those drugs can cause very bad high blood pressure.
• If you are taking another drug for weight loss or have taken one within the last year.

Children:

• If your child is younger than 12 years of age. Do not give this medicine to a child younger than 12 years of age.

This is not a list of all drugs or health problems that interact with benzphetamine.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

• Store at room temperature.
• Protect from light.
• Store in a dry place. Do not store in a bathroom.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Check with your pharmacist about how to throw out unused drugs.

Benzphetamine hydrochloride tablets 50 mg contain the anorectic agent Benzphetamine hydrochloride. Benzphetamine hydrochloride is a white crystalline powder readily soluble in water and 95% ethanol. The chemical name for Benzphetamine hydrochloride is d-N, α-Dimethyl-N-(phenylmethyl)- benzeneethanamine hydrochloride and its molecular weight is 275.82.

The structural formula (dextro form) is represented below:

Each Benzphetamine hydrochloride tablet for oral administration, contains 50 mg of Benzphetamine hydrochloride.

Inactive Ingredients: Calcium Stearate, Polyethylene Glycol, FD&C Yellow No. 6, Lactose Anhydrous, Sorbitol.

Obesity (short-term): Oral: Initial: 25 to 50 mg once daily; may increase to 25 to 50 mg 1 to 3 times daily based on response

Refer to adult dosing; use with caution starting at the low end of the dosage range.

Obesity (short-term): Children ≥12 years and Adolescents: Refer to adult dosing.

Administer midmorning or midafternoon (for single daily dose) based on patient’s eating habits; avoid late afternoon administration if possible.

Most effective when combined with a low calorie diet and behavior modification counseling.

General:
Drug Abuse and Dependence:
-This drug is related chemically and pharmacologically to amphetamines, which have been extensively abused.
-Abuse of amphetamines and related drugs may be associated with intense psychological dependence and severe social dysfunction.
-Abrupt cessation following prolonged high dosage results in extreme fatigue, mental depression, and sleep EEG changes.
-The possibility of abuse with this drug should be kept in mind when evaluating whether to use this drug as part of a weight reduction program.

Overdosage:
-Management of acute amphetamine intoxication is largely symptomatic and includes sedation with a barbiturate.
-Consider use of a nitrite or rapidly acting alpha receptor blocking agent if hypertension is marked.
-Urine acidification increases amphetamine excretion.
-Oral LD50 in rats is 104 mg/kg and 174 mg/kg in mice. The intraperitoneal LD50 is 153 mg/kg in mice.

Monitoring:
Cardiovascular: Cardiac evaluation (baseline), echocardiogram (during and after treatment), blood pressure
Metabolic: Weight
Other: Waist circumference

Patient advice:
-Avoid driving and other activities that require alertness (such as operating machinery) until you know how this drug affects you.