What is the dosage and treatment regimen for Albendazole (albendazole) in treating parasitic worm infestations?

Albendazole Dosing and Treatment Regimens for Parasitic Worm Infestations

Albendazole 400 mg as a single oral dose is the standard treatment for most common intestinal nematode infections including hookworm, roundworm (Ascaris), and pinworm (Enterobius), with the medication taken with food to enhance absorption. 1, 2

Standard Dosing by Infection Type

Single-Dose Regimens (400 mg)

• Hookworm (Ancylostoma/Necator): 400 mg single dose achieves 90-100% cure rates 1, 3
• Roundworm (Ascaris lumbricoides): 400 mg single dose with 100% efficacy 1, 3, 4
• Pinworm (Enterobius vermicularis): 400 mg single dose, repeated in 2 weeks to eliminate newly hatched worms 1, 5
• Whipworm (Trichuris trichiura): 400 mg single dose, though higher doses (600 mg) may improve efficacy for this organism 3

Weight-Based Dosing

• Patients ≥60 kg: 400 mg twice daily with meals 2
• Patients <60 kg: 15 mg/kg/day divided into two doses with meals (maximum 800 mg/day) 2

Extended Treatment Regimens

Hydatid Disease (Echinococcosis)

• Dosing: 400 mg twice daily (or 15 mg/kg/day if <60 kg) 2
• Duration: 28-day treatment cycle followed by 14-day drug-free interval, repeated for 3 total cycles 2
• Cyst size considerations: Albendazole alone for cysts <5 cm; combination with praziquantel for larger cysts 1
• Long-term therapy: Life-long courses may be required for E. multilocularis with frequent recurrence 1

Neurocysticercosis

• Dosing: 400 mg twice daily (or 15 mg/kg/day if <60 kg) 2
• Duration: 8-30 days depending on disease severity and location 2
• Parenchymal disease (1-2 cysts): Albendazole plus corticosteroids 1
• Parenchymal disease (>2 cysts): Combination albendazole plus praziquantel plus corticosteroids 1
• Subarachnoid cysts: Prolonged albendazole (15 mg/kg/day for months) or combination with praziquantel 50 mg/kg/day 1

Trichinellosis (Trichinella)

• Mild disease: 400 mg once daily for 3 days 1
• Severe disease: Extended courses with corticosteroids 1

Critical Administration Requirements

Food Requirement

Albendazole must be taken with food, particularly fatty meals, to enhance absorption by up to 5-fold. 2 This is essential for achieving therapeutic drug levels, especially for tissue infections.

Tablet Administration

• Tablets may be crushed or chewed and swallowed with water 2
• This is particularly useful for pediatric patients or those with swallowing difficulties 2

Empirical Treatment Approach

Asymptomatic Eosinophilia in Travelers

For returning travelers with eosinophilia and negative stool studies, empirical treatment with albendazole 400 mg single dose plus ivermectin 200 μg/kg is recommended to cover prepatent geohelminth infections. 1

• Repeat treatment at 8 weeks to address schistosomiasis if suspected, as eggs and immature schistosomulae are treatment-resistant 1
• Exclude Loa loa before ivermectin in patients from endemic regions to prevent severe adverse reactions 1

Mandatory Monitoring Requirements

Hematologic Monitoring

Monitor complete blood counts at the beginning of each 28-day cycle and every 2 weeks during therapy, as fatal bone marrow suppression has been reported. 2

• Discontinue immediately if clinically significant leukopenia or neutropenia develops 2
• Risk increases with prolonged therapy (>14-28 days) 1, 6

Hepatic Monitoring

Monitor liver enzymes (transaminases) at the start of each treatment cycle and at least every 2 weeks during therapy. 2

• Elevations occur in up to 16% of patients on chronic therapy 1
• Discontinue promptly if significant elevations occur; transaminases typically normalize after cessation 1

Pregnancy Testing

Obtain pregnancy test in all females of reproductive potential before initiating therapy, as albendazole causes fetal harm. 2

Special Clinical Situations

Neurocysticercosis-Specific Precautions

• Initiate corticosteroids before or concurrent with albendazole to prevent cerebral hypertensive episodes during the first week 2
• Screen for retinal cysticercosis before treatment, as retinal damage can occur 2
• Ensure anticonvulsant therapy is optimized, as seizure frequency may transiently increase 1

Pediatric Considerations

• Children aged >24 months: Standard 400 mg single dose for intestinal nematodes 1, 5
• Children aged 12-24 months: Discuss with expert before empirical treatment 1
• Children aged 2-6 years: Dose adjustments for weight-based regimens 5

Drug Interactions Requiring Dose Adjustment

Dexamethasone Co-administration

• Increases albendazole sulfoxide concentrations by 56% 2
• This interaction is clinically utilized in neurocysticercosis treatment 2

Praziquantel Co-administration

• Increases albendazole sulfoxide levels by 50% when taken with food 2
• Used therapeutically for combination treatment of complex cystic disease 2

Cimetidine Co-administration

• Doubles albendazole sulfoxide concentrations in bile and cystic fluid 2
• May enhance efficacy for hepatic hydatid disease 2

Theophylline Monitoring

• Albendazole induces CYP1A enzymes 2
• Monitor theophylline levels during and after albendazole treatment 2

Common Pitfalls to Avoid

Inadequate Treatment Duration

• Single-dose therapy is insufficient for tissue infections (hydatid disease, neurocysticercosis) 2
• Pinworm requires repeat dosing at 2 weeks due to reinfection from environmental eggs 5

Failure to Provide Adjunctive Therapy

• Neurocysticercosis requires corticosteroids to prevent inflammatory complications 2
• Hydatid disease may require surgical intervention for large or complicated cysts 1

Inadequate Monitoring

• Prolonged therapy (>14 days) without hematologic and hepatic monitoring risks serious toxicity 1, 2, 6
• Failure to exclude pregnancy before treatment exposes fetus to teratogenic risk 2

Taking Without Food

• Fasting administration results in inadequate drug absorption and treatment failure 2
• This is particularly critical for tissue infections requiring sustained therapeutic levels 2