Albendazole, a new high-efficiency broad-spectrum anthelmintic drug

Introduction

Albendazole is a broad-spectrum anthelmintic with high efficacy and low toxicity(picture 1). Clinically, it can be used to drive roundworms, pinworms, tapeworms, whipworms, hookworms, strongyloides, etc. After being metabolized to sulfoxide or sulfone in the body, it inhibits the parasite's absorption of glucose, leading to the depletion of glycogen in the parasite, or inhibits the fumarate reductase system, hindering the production of ATP, making the parasite unable to survive and reproduce. Albendazole is white or off-white powder, odorless, tasteless, insoluble in water, and slightly soluble in acetone or chloroform.

Picture 1 Albendazole tablets

Pharmacology and toxicology

Albendazole is a benzimidazole derivative, which is rapidly metabolized into sulfoxide, sulfone alcohol and 2-amine sulfone alcohol in vivo. Selectively and irreversibly inhibits the polymerization of the cytoplasmic microtubule system in intestinal parietal cells in intestinal nematodes, blocking its uptake and absorption of various nutrients and glucose, leading to depletion of endogenous glycogen in worms, and inhibiting the reduction of fumarate The enzyme system prevents the production of adenosine triphosphate, making the parasite unable to survive and reproduce. Similar to mebendazole, this product can also cause degeneration of cytoplasmic microtubules in intestinal cells of parasites, and bind to its tubulin, causing blockage of intracellular transport, resulting in the accumulation of endocrine granules in the Golgi body, gradual dissolution of cytoplasm, and complete degeneration of absorbing cells. cause the worm to die. This product can completely kill hookworm eggs and whipworm eggs and partially kill roundworm eggs. In addition to killing and expelling various nematodes parasitic in animals, it also has obvious killing and expelling effects on tapeworms and cysticercosis.

Toxicological tests show that this product is less toxic and safe. The oral LD50 of mice is more than 800mg/kg, and the maximum tolerated dose of dogs is more than 400mg/kg. This drug has no effect on the reproductive function of male mice, and has no teratogenic effect on female mice. In female rats and female rabbits, when a higher dose (30mg/kg/day) is used, fetal absorption and bone marrow can occur. deformities, etc.

Scope of application

This product is a new high-efficiency broad-spectrum anthelmintic drug, which is one of the benzimidazole drugs with a broad anthelmintic spectrum and the strongest insecticidal effect. It is highly active against nematodes, schistosomes and tapeworms, and has a significant inhibitory effect on egg development.

It also has obvious expelling effect on various nematodes, schistosomes, tapeworms and cysticercosis parasitic on animals. It is suitable for expelling roundworms, pinworms, hookworms, whipworms, and for deworming livestock. Clinical observation of 556 cases proved that the negative conversion rates of hookworm, roundworm, pinworm and whipworm eggs were 100%, 96.4%, 98.9% and 70% respectively. This product can still be used to treat various types of cysticercosis, such as cerebral and dermatomuscular types, with a markedly effective rate of over 80%. For the treatment of trichinosis, the total effective rate is 100%, and its curative effect is better than that of mebendazole.

Precautions

(1) A small number of cases have mild headache, dizziness, nausea, vomiting, diarrhea, dry mouth, fatigue and other adverse reactions, which can disappear without treatment.

(2) Children under the age of 2 and pregnant women are prohibited.

(3) It is not suitable for patients with acute disease, proteinuria, suppurative or diffuse dermatitis, epilepsy, and lactating women. Use with caution in patients with severe hepatic, renal, and cardiac insufficiency and active ulcer disease.

(4) In a few patients, the deworming effect may appear within 3 to 10 days after the eye drops.

(5) During the treatment of cysticercosis, some patients may experience different degrees of dizziness, headache, fever, urticaria and other reactions. The degree of reaction is related to the number of cysticercosis, parasitic site and body reaction. Patients with severe infection must be hospitalized, cerebrospinal fluid and fundus examinations should be performed, and close observation should be made. Dexamethasone and 20% mannitol can be given as appropriate when necessary. No treatment is required for dermatomuscular cysticercosis.

Pharmacokinetics

Albendazole is insoluble in water, so it is slowly absorbed in the intestinal tract. The original drug is converted into propylthiobendazole-sulfoxide and propylthiobendazole-sulfone in the liver, and the former is an insecticidal component. The distribution of this product in the body is in the liver, kidney, and muscle. It can pass through the blood-brain barrier and has a certain concentration in the brain tissue. The peak plasma concentration is reached 2.5 to 3 hours after oral administration. The concentration of the original drug and sulfone derivatives in the blood is extremely low and cannot be measured. The concentration of prothionimidazole-sulfoxide varied greatly, ranging from 0.04 μg/ml to 0.55 μg/ml, with an average of 0.16 μg/ml. Half-life in blood (t1/2) is 8.5 to 10.5 hours. 87% of this product and its metabolites are excreted from urine and 13% from feces within 24 hours, and there is no accumulation in the body.

Renference

1 National Essential Medicines List (2018 Edition)

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