A 3-year-old child presents with bloody diarrhea following recent deworming. Albendazole had been prescribed for a round-worm infection. The mechanism by which albendazole kills helminths is:

• A Binding to beta-tubulin of helminth microtubules, inhibiting polymerization and disrupting glucose uptake ✓
• B Irreversible activation of helminth chloride channels, causing hyperpolarization and paralysis
• C Inhibition of fumarate reductase in the helminth mitochondrial electron transport chain
• D Opening of nicotinic acetylcholine receptor channels, causing spastic paralysis

Explanation

Albendazole (and mebendazole) bind selectively to the beta-tubulin of nematode and helminth microtubules, inhibiting their polymerization and disrupting the microtubule-dependent uptake of glucose. Depletion of glycogen stores leads to energy depletion and death of the parasite. Human beta-tubulin has much lower affinity for the drug, providing selectivity. Ivermectin acts on chloride channels; piperazine causes flaccid paralysis via GABA; pyrantel acts on nicotinic receptors causing spastic paralysis.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.