Clinical presentation and diagnosis Pharmacologic Therapy

O All symptomatic adults and children over the age of 8 years with giardiasis should be treated with metronidazole 250 mg three times daily for 7 days, or tinidazole 2 g

as a single dose, or nitazoxanide (Alina) 500 mg twice daily for 3 days. , The pediatric dose of metronidazole is 15 mg/kg/day three times daily for 7 days. Alternative drugs include furazolidone 100 mg four times daily or paromomycin 25 to 35 mg/kg/day in divided doses daily for 7 days. Paromomycin may be used in pregnancy instead of metronidazole. Pediatric patients can also be treated with suspensions of either furazolidone 6 mg/kg/day in four divided doses for 7 days.

Clinical Presentation and Diagnosis of Giardiasis Acute Onset

• Diarrhea, cramp-like abdominal pain, bloating, and flatulence

• Malaise, anorexia, nausea, and belching Chronic Symptoms

• Diarrhea: Foul-smelling, copious, light-colored and greasy stools

• Weight loss, steatorrhea, and vitamin B12 and fat-soluble vitamin deficiencies

• Constipation alternating with diarrhea Diagnosis

• Diagnosis is made by examination of fresh stool or a preserved specimen during acute diarrheal phase

• Fresh stool may show trophozoites while preserved specimens yield cysts. (Note: stool for ova may show the presence of other parasites [e.g., Cryptosporidium par-vum, E. histolytica, or E. hartmanni]; multiple stool samples may be needed.)

• Even though stool examination for ova and parasites has remained the major means of diagnosis, other diagnostic tests include enzyme-linked immunosorbent assay (ELISA), which is considered to be between 85% and 98% sensitive and almost 100% specific (ProSpec T, Giardia Microplate Assay, Remel, Lenexa, KS).

Quinacrine 100 mg three times in adults or 5 mg/kg/day in pediatric patients for 5 to 7 days, is available from a specialized pharmacy (e.g., Ponorama Compounding Pharmacy).12

Patient Care and Monitoring: Giardiasis

• Metronidazole produces cure rates between 85% and 95%.

• Diarrhea will cease within a few days, although in some patients it may take 1 to 2 weeks.

• Cyst excretion will cease within days.

• Intestinal dysfunction (manifested as increased transit time) and radiologic changes primarily due to chronic infection may take months to resolve.

• Patients who fail therapy with metronidazole should receive a second course with either metronidazole or an alternative agent; nitazoxanide has been shown to be effective in resistant giardiasis.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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