antibiotics

What is the standard dosage of amoxicillan which is given by dentists to people with heart murmurs. I'm a 19 year old female weighing 112 with moderate mitral regurgitation and my dentist has prescribed four 500mg caplets of amoxicillan to be taken 1 hour prior to the appointment. Isn't that a rather high dosage? I have never taken that much amoxicillan in one day let alone in one hour. Please advise as to the standard dosage in this situation. Thank you for your help.

[Cleveland Clinic, MD]

2000 mg is the standard pre-dental amoxicillin dosage for individuals at risk for developing endocarditis.