Medical Editor: John P. Cunha, DO, FACOEP
What Is Vermox?
Vermox (mebendazole) is an "antihelmintic," or anti-worm, medication used to treat infections caused by worms such as whipworm, pinworm, roundworm, and hookworm. Vermox is also used to treat infections caused by more than one of these worms at the same time. The brand name Vermox is no longer available in the U.S. Generic versions may be available.
What Are Side Effects of Vermox?
Common side effects of Vermox (mebendazole) include:
- stomach/abdominal pain,
- vomiting,
- diarrhea,
- fever,
- headache,
- dizziness, or
- drowsiness.
Dosage for Vermox
The dose of mebendazole for children and adults to treat whipworm, roundworm, and hookworm is 1 tablet taken morning and evening for 3 consecutive days. The dose to treat pinworm is 1 tablet, taken just once.
What Drugs, Substances, or Supplements Interact with Vermox?
Mebendazole may interact with seizure medications. Tell your doctor all medications you use.
Vermox During Pregnancy and Breastfeeding
During pregnancy, mebendazole should be used only when prescribed. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.
Additional Information
Our Vermox (mebendazole) 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.

SLIDESHOW
Digestive Disorders: Common Misconceptions See SlideshowGet 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:
- signs of bone marrow suppression--sudden weakness or ill feeling, fever, chills, sore throat, mouth sores, red or swollen gums, trouble swallowing, easy bruising or bleeding; or
- severe skin reaction--swelling in your face or tongue; sores around your eyes, nose, mouth, or genitals; hives or skin rash that spreads and causes blistering and peeling.
Common side effects may include:
- nausea, vomiting, loss of appetite, diarrhea;
- stomach pain, gas; or
- rash.
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.

QUESTION
About how much does an adult human brain weigh? See AnswerSIDE EFFECTS
Clinical Studies
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The safety of mebendazole was evaluated in 6276 adult and pediatric subjects one year of age and older who participated in 39 clinical trials for treatment of single or mixed parasitic infections of the gastrointestinal tract. In these trials, the formulations, dosages and duration of mebendazole treatment varied. Adverse reactions reported in mebendazole-treated subjects from the 39 clinical trials are shown in Table 1 below.
Table 1: Adverse Reactions Reported in Mebendazole-Treated Subjects from 39 Clinical Trials*
Adverse Reaction(s) |
Gastrointestinal Disorders |
Anorexia |
Abdominal Pain |
Diarrhea |
Flatulence |
Nausea |
Vomiting |
Skin and Subcutaneous Tissue Disorders |
Rash |
* Includes mebendazole formulations, dosages and treatment duration other than VERMOX™ CHEWABLE 500 mg tablet |
Clinical Studies With Mebendazole Chewable 500 mg Tablet
The safety profile of mebendazole chewable 500 mg tablets administered as a single dose was evaluated in 677 pediatric subjects aged 1 to 16 years and in 34 adults. The safety profile was consistent with the known safety profile of mebendazole.
Postmarketing Experience
The following adverse reactions have been identified in adult and pediatric patients postmarketing with mebendazole formulations and dosages other than the VERMOX™ CHEWABLE 500 mg tablet. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Table 2: Adverse Reactions Identified During Postmarketing Experience with Mebendazole*
Adverse Reaction(s) | |
Blood and Lymphatic System Disorders | Agranulocytosis, Neutropenia |
Immune System Disorders | Hypersensitivity including anaphylactic reactions |
Nervous System Disorders | Convulsions, Dizziness |
Hepatobiliary Disorders | Hepatitis, Abnormal liver tests |
Renal and Urinary Disorders | Glomerulonephritis |
Skin and Subcutaneous Tissue Disorders | Toxic epidermal necrolysis, Stevens-Johnson syndrome,Exanthema, Angioedema, Urticaria, Alopecia |
* Includes mebendazole formulations, dosages and treatment durations other than VERMOX™ CHEWABLE 500 mg tablet |
DRUG INTERACTIONS
Concomitant use of mebendazole and metronidazole should be avoided [see WARNINGS AND PRECAUTIONS].
Read the entire FDA prescribing information for Vermox (Mebendazole)
© Vermox Patient Information is supplied by Cerner Multum, Inc. and Vermox Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.
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