Once Daily Metronidazole for Perforated Appendicitis

Metronidazole Every 24 Hours as Part of Triple Antibiotic Therapy for Ruptured Appendicitis in Children Managed Operatively (METRO): a Noninferiority Randomized Controlled Trial

The objective of this study is to determine whether administering once-daily doses of metronidazole, an intravenous (IV) antibiotic used to prevent infection in perforated appendicitis, is as effective in children as delivering it in the standard method of once every eight hours. Reducing the frequency of administration has the potential of decreasing personnel time and healthcare cost and increasing the lifespan of the IV line.

To determine the effectiveness once-daily administration, a randomized controlled trial (RCT) will be conducted to compare outcomes between the two treatment schedules. We will recruit 100 patients (50 per treatment) aged 5-18 being surgically treated for perforated appendicitis at the Children's Hospital of Eastern Ontario, who will be randomly assigned to one of the two treatment schedules. To compare the efficacy of the treatments, outcomes such as duration of hospital stay and theoretical cost will be measured and analyzed using statistical tests.

Inclusion Criteria:

• All children 5-18 years of age, presenting to CHEO with perforated appendicitis (confirmed either in the operating room or diagnosed preoperatively according to radiological criteria), and managed surgically will be assessed for eligibility to participate. These patients may participate if baseline lab values of serum AST (SGOT), AL T (SGPT), LDH, triglycerides and hexokinase glucose are normal, complete physical exam is normal, hGC test is negative for pregnancy (if the patient is a female of reproductive age) and none of the exclusion criteria are present.

Exclusion Criteria:

• Any known co-existing gastrointestinal disease
• Uncertainty about the diagnosis
• Perforated appendicitis with diffuse abdominal fluid on imaging associated with a clinical picture of severe sepsis
• A known allergy to any of the antibiotics to be used in this trial
• An active neurological disorder
• Receiving medical treatment for a neurological disorder
• A history of blood dyscrasia, hypothyroidism or hypoadrenalism
• Hepatic disease
• Renal impairment
• Patients receiving any other oral or intravenous concomitant antimicrobial at enrollment
• Pregnancy
• Under five years of age
• Patients who have received metronidazole orally or intravenously in the last 14 days, prior to the current admission for appendicitis
• Patients already taking any of the following medications at admission (as these may interact with Metronidazole as stated in the product monograph): disulfiram, oral anticoagulant therapy (warfarin type), phenytoin or phenobarbital, vecuronium, lithium, busulfan
• The physician elects to treat the patient conservatively (non-surgically)