The dosage of albendazole can vary significantly depending on the type of infection being treated, the patient's age, weight, and overall health condition. Generally, the standard adult dosage for treating common infections such as ascariasis (roundworm) is 400 mg taken orally as a single dose. For children aged two years and older, the dosage is typically based on their weight, often prescribed at 15 mg/kg up to a maximum of 400 mg.