Bontril Side Effects Center

Last updated on RxList: 2/17/2021
Bontril Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

What Is Bontril?

Bontril PDM (phendimetrazine tartrate) is an appetite suppressant, used along with a doctor-approved, reduced-calorie diet, exercise, and a behavior change program to help patients lose weight. Bontril PDM is used in people who are significantly overweight (obese) and have not been able to lose enough weight with diet and exercise alone.

What Are Side Effects of Bontril?

Common side effects of Bontril PDM include:

  • dizziness,
  • dry mouth,
  • blurred vision,
  • difficulty sleeping (insomnia),
  • restlessness,
  • hyperactivity,
  • headache,
  • tremors,
  • flushing (warmth, redness, or tingly feeling),
  • diarrhea,
  • constipation,
  • upset stomach,
  • increased or decreased interest in sex, or
  • impotence

Dosage for Bontril

The recommended dosage of Bontril PDM is 1 tablet (35 mg) 2-3 times daily, one hour before meals.

What Drugs, Substances, or Supplements Interact with Bontril?

Bontril PDM may interact with other drugs. Tell your doctor all prescription and nonprescription/herbal products you may use, especially: drugs for depression, diabetes, high blood pressure, or other stimulants. Do not drive, use machinery, or do any activity that requires alertness or clear vision when taking Bontril PDM. Avoid alcoholic beverages. Caffeine can increase side effects of this medication.

Bontril During Pregnancy and Breastfeeding

Bontril PDM should not be taken during pregnancy. Consult your doctor before using Bontril PDM if you are breastfeeding.

Additional Information

Our Bontril PDM (phendimetrazine tartrate) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Bontril Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • pounding heartbeats or fluttering in your chest;
  • tremors, severe agitation, feeling restless, trouble sleeping;
  • unusual changes in mood or behavior;
  • little or no urination; or
  • increased blood pressure--severe headache, blurred vision, pounding in your neck or ears, anxiety, nosebleed.

Common side effects may include:

  • flushing (warmth, redness, or tingly feeling);
  • increased sweating or urination;
  • dizziness, headache;
  • blurred vision;
  • dry mouth, nausea;
  • diarrhea, constipation, stomach pain; or
  • increased or decreased interest in sex.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Bontril Professional Information


Cardiovascular: Palpitation, 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 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: Bontril® PDM (phendimetrazine tartrate) is 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.

Read the entire FDA prescribing information for Bontril (Phendimetrazine Tartrate Tablets)

© Bontril Patient Information is supplied by Cerner Multum, Inc. and Bontril Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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