Bontril SR Side Effects Center

Last updated on RxList: 6/15/2021
Bontril SR Side Effects Center

What Is Bontril SR?

Bontril SR (phendimetrazine tartrate) is a sympathomimetic amine, which is similar to an amphetamine, used as a short-term supplement to diet and exercise in the treatment of obesity.

What Are Side Effects of Bontril SR?

Common side effects of Bontril SR include:

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

Dosage for Bontril SR

The recommended dose of Bontril SR is one Slow-Release Capsule (105 mg) in the morning, taken 30-60 minutes before the morning meal.

What Drugs, Substances, or Supplements Interact with Bontril SR?

Bontril SR may interact with monoamine oxidase inhibitors (MAOIs), insulin and other diabetes drug therapies, guanethidine, or tricyclic antidepressants. Tell your doctor all medications and supplements you use.

Bontril SR During Pregnancy or Breastfeeding

During pregnancy, Bontril SR should be used only when prescribed. It is not recommended for use near the expected delivery date because of possible harm to the fetus. Infants born to mothers who have been using this medication may have withdrawal symptoms such as irritability or extreme tiredness. Tell your doctor if you notice symptoms in your newborn. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding. Withdrawal symptoms may occur if you suddenly stop taking this medication.

Additional Information

Our Bontril SR (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 SR 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 SR Professional Information


Cardiovascular: Palpitation, tachycardia, elevation of blood pressure.

Central Nervous System: Overstimulation, restlessness, dizziness, insomnia, tremor, headache; rarely psychotic episodes at recommended doses, agitation, flushing, sweating, blurring of vision.

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

Genitourinary: Changes in libido, urinary frequency, dysuria.

Drug Abuse And Dependence

Controlled Substance: Phendimetrazine 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 SR (Phendimetrazine Tartrate Slow Release Capsules)

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

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