A man aged 69 years non-diabetic painter by profession, alcohol addict has poor dental hygiene. He plans for remaining teeth extraction for subsequent dentures. He is suffering of mitral valve stenosis with mild cardiac insufficiency and is being treated with captopril, digoxin and frusemide.

The dentist and the physician are worried about prophylactic antibiotic to prevent endocarditis  Suggest the most suitable antibiotic to prevent bacteremia and endocarditis.