I have successfully for 7 years used Tagamet (Cimetidine) dosed 25-40 mg/kg body weight divided into 2 daily doses. Generally speaking, I will use 400 mg twice a day in child under 10 years old. Older children, I will use 800 mg twice a day. If the patient can not swallow pills, Tagamet comes in a liquid 300 mg/5ml. The rate of success is 80% in children under 18 years old and about 30% in people older than 18. I have used Tagamet in children as young as 2 and in adults 65 years old. I tell my patients if there is no change in the warts by 2 months, then it is not likely to work.
I have had a pharmacist mix up Cimetidine in a lecithin compound to use topically and it worked on my son. Most of my patients do not want to pay for this themselves when their insurance will pay for the pills.
I hope this information is helpful.
Vivian Abrams DPM