Overview

Fever bark is the bark of an evergreen tree called Alstonia constricta. The tree is native to Australia and grows to 15 meters tall.

Fever bark contains the chemicals yohimbine and reserpine, which can lower blood pressure. These chemicals might also be unsafe.

People use fever bark for high blood pressure, malaria, rheumatoid arthritis (RA), and many other conditions, but there is no good scientific evidence to support these uses.

Don't confuse fever bark with Cinchona, which is sometimes called fever bark or fever tree. These are not the same.

Uses & Effectiveness

We currently have no information for Fever Bark overview.

Side Effects

When taken by mouth: Fever bark is possibly unsafe. It contains the chemicals yohimbine and reserpine, which can cause serious side effects, including depression, psychotic reactions, and heart failure.

Special Precautions and Warnings

When taken by mouth: Fever bark is possibly unsafe. It contains the chemicals yohimbine and reserpine, which can cause serious side effects, including depression, psychotic reactions, and heart failure.

Pregnancy and breast-feeding: There isn't enough reliable information to know if fever bark is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.

Anxiety: A chemical in fever bark might make anxiety worse.

Depression: A chemical in fever bark might make depression worse.

Stomach ulcers: Some of the chemicals in fever bark might make stomach ulcers worse.

Schizophrenia: Some of the chemicals in fever bark might cause a psychotic episode.

Surgery: Some chemicals in fever bark act like stimulants and might increase the risk of bleeding. Fever bark might interfere with surgery by increasing heart rate, blood pressure, and bleeding risk. Stop using fever bark at least 2 weeks before a scheduled surgery.

Interactions

    Moderate Interaction

    Be cautious with this combination

  • Medications used during surgery (Anesthesia) interacts with Fever Bark

    Fever bark contains a chemical called reserpine. Taking reserpine along with medications used for surgery can cause heart problems. Be sure to tell your doctor what natural products you are taking before having surgery. You should stop taking fever bark at least two weeks before surgery.

  • Phenothiazines interacts with Fever Bark

    Fever bark contains a chemical called yohimbine. Some phenothiazines have effects similar to yohimbine. Taking fever bark and phenothiazines together might increase the effects and side effects of both.

  • Stimulant drugs interacts with Fever Bark

    Stimulant drugs speed up the nervous system. By speeding up the nervous system, stimulant medications can make you feel jittery and speed up your heartbeat. Fever bark might also speed up the nervous system. Taking fever bark along with stimulant drugs might cause serious problems including increased heart rate and high blood pressure.

  • Medications changed by the liver (Cytochrome P450 2D6 (CYP2D6) substrates) interacts with Fever Bark

    Some medications are changed and broken down by the liver. Fever bark might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

  • Medications for depression (MAOIs) interacts with Fever Bark

    Fever bark contains a chemical called yohimbine. Yohimbine might affect the body in some of the same ways as some medications for depression called MAOIs. Taking fever bark along with MAOIs might increase the effects and side effects of MAOIs.

    Some common MAOIs include phenelzine (Nardil), selegiline (Zelapar), and tranylcypromine (Parnate).

  • Medications for high blood pressure (Antihypertensive drugs) interacts with Fever Bark

    Fever bark might increase or decrease blood pressure. Taking fever bark along with medications that lower blood pressure might reduce the effects of these medication or cause blood pressure to go too low. Monitor your blood pressure closely.

  • Medications that decrease break down of other medications by the liver (Cytochrome P450 2D6 (CYP2D6) inhibitors) interacts with Fever Bark

    A chemical in fever bark, yohimbine, is changed and broken down by the liver. Some drugs decrease how quickly the liver changes and breaks down yohimbine. This could change the effects and side effects of fever bark.

  • Medications that decrease break down of other medications in the liver (Cytochrome P450 3A4 (CYP3A4) inhibitors) interacts with Fever Bark

    A chemical in fever bark, yohimbine, is changed and broken down by the liver. Some drugs decrease how quickly the liver changes and breaks down yohimbine. This could change the effects and side effects of fever bark.

    Minor Interaction

    Be watchful with this combination

  • Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with Fever Bark

    Fever bark might slow blood clotting. Taking fever bark along with medications that also slow clotting might increase the chances of bruising and bleeding.

Dosing

There isn't enough reliable information to know what an appropriate dose of fever bark might be. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult a healthcare professional before using.
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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is licensed from Therapeutic Research Center, LLC. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
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