Question

The physician orders an initial dose of Medication M 500 mg PO BID for a 12-year-old patient with complex partial seizures who weighs 40 kg. The drug reference entry for Medication M states:

PO (Adults and Children older than 10 yr): Single agent therapy (complex partial seizures)—Initial dose of 10–15 mg/kg/day in 1–4 divided doses; Increase by 5–10 mg/kg/day weekly until therapeutic response is achieved (not to exceed 60 mg/kg/day); when daily dose exceeds 250 mg, give in divided doses.

What is the recommended dosage range for this patient? Is the ordered dose safe?

Answer 1

The recommended initial dosage range for a 40 kg child over 10 years old with complex partial seizures is 400–600 mg per day of Medication M, divided into two doses. The ordered dose of 500 mg twice daily (1000 mg per day) exceeds this range and could be unsafe. It is essential to follow the recommended dosages to avoid side effects or toxicity.

Step-by-step explanation:

The question pertains to the dosage and safety of Medication M, an anticonvulsant, for a 12-year-old patient weighing 40 kg, diagnosed with complex partial seizures. According to the drug reference, the initial dosage range for children older than 10 years is 10–15 mg/kg/day given in divided doses. For a 40 kg child, this equates to an initial dose range of 400–600 mg/day, potentially given in two divided doses (since the medication is ordered to be taken BID, which stands for twice daily).

The physician has ordered an initial dose of 500 mg twice daily, which amounts to a total daily dosage of 1000 mg. Comparing this to the recommended initial dosage range of 400-600 mg per day, it is apparent that the ordered dose exceeds the recommended dosage and could potentially be unsafe. It is crucial to adhere to the recommended dosage to minimize the risk of side effects and toxicity.

Attention to units is vital because, without specific units, dosing can lead to confusion and significant medical errors. Thus, for a 12-year-old patient weighing 40 kg with complex partial seizures, the safe and recommended initial dosage of Medication M would be 400–600 mg per day, divided into two doses, and not the 1000 mg per day that has been ordered.