mebendazole

Action and Spectrum

Action:

Mebendazole prevents the parasitic worms to produce microtubules. Microtubules are important for the survival and metabolism for parasites. The parasites die because of the absence of microtubules.

Spectrum:

Mebendazole is affective against the different parasitic worms like hookworms (Necator americanus, Ancylostoma duodenale), roundworms (Ascaris lumbricoides), pinworms (Enterobius vermicularis), and whipworms (Trichuris trichiura) and tapeworms like Hymenolepis nana and Taenia saginata.

Drug Interaction

Adverse Reaction

Frequency defined:

Frequency Not Defined

Angioedema

Fever

Dizziness

Drowsiness

Decreased hemoglobin.

Rash

Itching

Headache

Hematuria

Leukopenia

Seizures

Agranulocytosis

Alopecia

Abdominal pain

Diarrhea

Nausea

Toxic epidermal necrolysis

May increase AST, ALT, and GGT (hepatitis)

Stevens-Johnson syndrome

Vomiting

Neutropenia (sore throat, unusual fatigue)

Toxic epidermal necrolysis

Unusual weakness

Glomerulonephritis

Black Box Warning

The US Food and Drug Administration (FDA) has not reported any black box warning for mebendazole.

Contraindication / Caution

Contraindication/Caution:

Contraindications:

Hypersensitivity:

Mebendazole must not be used if patient is allergic to it or any other components present in it.

Caution

Liver disease: Patient who has liver disease can be at the risk to damage the liver by using mebendazole. It is needing to do the liver function test before and during the treatment of this medication.

Mebendazole is eliminated by the kidney. People who have impaired function of kidney may accumulate the drug. Modification in the dosage may needed.

Mebendazole is safe in children besides the small children and newborn must be handles with care because of the possibility to choke the tablet. For children who are not able to swallow the tablets, the tablet must be crushed and mixed with food.

Old patient must take caution as there is limited information on the usage of mebendazole.

Pregnancy / Lactation

Pregnancy consideration:

Pregnancy category: C

Mebendazole is categorized as pregnancy category C. It indicates that it can be harmful to fetus. It is only use if the benefits are more than the risk during the pregnancy.

Breastfeeding: Mebendazole may impact on a newborn because of the secretion of it in the human milk. Breastfeeding must be stopped in these cases.

Pregnancy Categories:     

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester.

Category B: There were lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.

Category N: There is no data available for the drug under this category

Pharmacology

Mebendazole is an anthelmintic drug and comes from benzimidazole class of compound. It interferes with the ability of parasites to form the microtubules and leads to the lack of energy in the parasites and death.

Pharmacodynamics:

Mebendazole is effective against roundworms, hookworms, whipworms, and pinworms. It kills the parasites in adults and larval stage. The ability of parasites to from the microtubules is affected by mebendazole and lacks the energy and lead to death. The toxicity of drug on the human cells is caused by little and has no impact on the human microtubules.

Pharmacokinetics:

Absorption:

Mebendazole is not well absorbed in the GI tract. About 5 to 10% of the oral dosage can reach to the systemic circulation. The solubility of mebendazole is elevated and absorption is taken place with the fatty meal and improve it.

Distribution:

Mebendazole is distributed in the body because of the weak solubility in the water. This distribution is limited. It has a great affinity towards the fat, and it is very lipophilic. In rare case, it interacts with the plasma protein.

Metabolism:

The cytochrome P450 (CYP) enzyme metabolize mebendazole in the liver. It has 2 main active metabolites like 2-amino-5-benzoylbenzimidazole (ABB) and hydroxy-mebendazole. They eliminated by the urine and feces.

Elimination and Excretion:

Mebendazole and it’s metabolites are eliminated by the urine and feces. Most of it is eliminated in the form of metabolites and about 2% in the unaltered form. The elimination ½ life is about 3 to 6 hours. Patient who has liver disease may have long ½ life.

Adminstartion

Mebendazole is taken orally in the form of tablets or chewable pills. It can by taken with or without food and must be taken with a glass of water. The absorption of mebendazole is elevated if it is taken with food.

Patient Information Leaflet

Generic Name: Pronounced: [me-BEN-da-zole]

Why do we use mebendazole?

Mebendazole is used to treat a different parasitic infection occurred by helminths. It is an anthelmintic medication. I prevent the worms to absorb the glucose and lead to lack of energy and eventually to the death.