Question

• A 2 month old baby girl presents with 2 weeks of regular crying episodes and fussiness.  You diagnose colic and the father asks about the usefulness of simethicone.

Clinical Bottom Lines

1. Simethicone and placebo both produced improvement in symptoms of colic.
2. Improvement seen due to simethicone or placebo may be due to placebo effect or the tendency of colic symptoms to lessen as infants grow older.

Summary of Key Evidence

1. 83 patients were randomized to receive either simethicone or placebo for 3-10 days followed by crossover into opposite treatment group for the next 3-10 days.  Trial was a double blind, placebo controlled, crossover format.¹
2. Inclusion criteria - Wessel’s definition for colic: "One who, otherwise healthy and well-fed, has paroxysms of irritability, fussing or crying for more than 3 hours a day and occurring on more than 3  days in any one week."  In addition, patients had to be full term, AGA, between 2-8 weeks of age, demonstrated weight gain of 5 or more ounces per week, and normal history and physical.
3. Exclusion criteria:  Prior to current diagnosis of illness, history of treatment for hyperbilirubinemia, congenital or acquired abnormalities which might predispose patient to irritability.
4. Outcome measured by daily diary recording child’s diet, other medications administered, number of episodes of colic, time of study medication administration and parents’ assessment of symptoms (definitely better, possibly better, same, possibly worse, definitely worse).
5. 83 patients were randomized to two groups (simethicone or placebo). Treatment lasted 3-10 days after which parents were to turn in medication and get the opposite study medication.  25% of those treated with simethicone reported definite or probable improvement.  29% of those treated with placebo reported definite or probable improvement.  24% reported no change with either drug, 22% reported definite or probable worsening with either drug.

Additional Comments

• Simethicone is said to reduce intestinal gas by decreasing transit time through the gut but even in patients whose parents reported gas as a symptom, placebo was as effective as simethicone in reducing symptoms. Thus is colic caused by gas or multiple factors?
• Medications were supplied by Stuart Pharmaceuticals (makers of Mylicon).
• Placebo was indistinguishable in taste, smell and appearance from Mylicon.
• Other prior studies lacked clear definition of colic, lack of placebo, lack of blindedness, specifics on dosage, or had a small number of subjects.
• Cost of simethicone is $7-$10 per 30 ml bottle.

Citation

1. Metcalf TJ,  Irons TG, Sher LD, Young PC.  Simethicone in the treatment of infant colic: A randomized, placebo-controlled, multicenter trial; Pediatrics 1994; 94:29-34.

CAT Author: Leena Dev, MD

CAT Appraisers: John G. Frohna, MD

Date appraised: August 10, 1998