From the Guidelines
The treatment for Giardiasis (Giardia infection) is typically tinidazole as the first choice, with metronidazole as an alternative option. According to the 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea 1, tinidazole is the preferred treatment for Giardia lamblia, while metronidazole is an alternative due to its high frequency of gastrointestinal side effects.
Key Considerations
- Tinidazole is approved in the United States for children aged ≥3 years and is available in tablets that can be crushed 1.
- Metronidazole has a high frequency of gastrointestinal side effects and is not FDA-approved for the treatment of giardiasis, although a pediatric suspension can be compounded from tablets 1.
Treatment Options
- Tinidazole: 2 g once as a single dose
- Metronidazole: 250 mg three times daily for 5-7 days for adults, and 15 mg/kg/day divided into three doses for 5-7 days for children
Additional Recommendations
- Patients should avoid alcohol consumption during treatment, especially with metronidazole and tinidazole, due to potential disulfiram-like reactions.
- Adequate hydration is essential to prevent dehydration from diarrhea.
- Treatment is necessary even for asymptomatic carriers to prevent transmission to others.
- If symptoms persist after treatment, a second course with an alternative medication may be needed, as treatment failure occurs in approximately 10-20% of cases.
From the FDA Drug Label
1.2 Giardiasis Tinidazole is indicated for the treatment of giardiasis caused by Giardia duodenalis (also termed G. lamblia) in both adults and pediatric patients older than three years of age [see Clinical Studies ( 14.2)] 14. 2 Giardiasis Tinidazole (2 g single dose) use in giardiasis has been documented in 19 published reports from the world literature involving over 1,600 patients (adults and pediatric patients)
The treatment for Giardiasis (Giardia infection) is Tinidazole. The recommended dose is a 2 g single dose for adults and 50 mg/kg × 1 day for pediatric patients 2. Reported cure rates with this dose range from 80% to 100% 2.
From the Research
Treatment Options for Giardiasis
The treatment for Giardiasis (Giardia infection) typically involves the use of antimicrobial medications. The following are some of the treatment options:
- Tinidazole: a first-line drug treatment that requires only a single dose to cure infection in most individuals 3, 4, 5, 6
- Metronidazole: an effective treatment, but it requires 5 to 7 days of three times a day therapy 3, 7, 5, 6
- Nitazoxanide: appears to be as effective as tinidazole or metronidazole, and it does not have the bitter taste of nitroimidazoles 3, 7, 5
- Paromomycin: a good alternate for use during pregnancy 3
- Albendazole: may be of similar effectiveness to metronidazole, may have fewer side effects, and has the advantage of a simplified regimen 7, 5
- Mebendazole: has been evaluated, but reliable conclusions on the relative effectiveness cannot be made due to high risk of bias and small trial size 7
Efficacy of Treatment Options
The efficacy of these treatment options varies:
- Tinidazole has been associated with higher parasitological cure than metronidazole and albendazole 5
- Metronidazole has been shown to be effective, but may have more side effects than albendazole 7
- Nitazoxanide has been evaluated, but the evidence is limited 3, 7, 5
- Single-dose tinidazole has been found to be the most effective drug for giardiasis in symptomatic and asymptomatic children and adults 5
Side Effects and Considerations
The side effects and considerations of these treatment options include:
- Tinidazole: rarely vomiting may occur, and the patient may need to be re-treated with a multiple dose regimen 4
- Metronidazole: may have more side effects than albendazole, including gastrointestinal and neurological side effects 7
- Albendazole: may have fewer side effects than metronidazole, but the evidence is limited 7