Once-daily amoxicillin works as well as penicillin for strep throat

A study published in Archives of Disease in Childhood shows that one daily dose of amoxicillin by mouth works as well as penicillin V twice a day for throat infection caused by group A beta-haemolytic streptococcus (GABHS) in children at high risk of acute rheumatic fever.

Rheumatic fever is a complication of GABHS throat infection, and rheumatic heart disease is the most common cause of death from heart disease in children in many parts of the world.

The study included 353 children with GABHS throat infection, treated for 10 days with either amoxicillin once a day (1,500 mg, or 750 mg if they weighed 30 kg or less) or penicillin V 500 mg twice a day (250 mg if they weighed 20 kg or less). The main aim was clearing the bacteria, checked with throat swabs on days 3–6, 12–16 and 26–36; the bacteria were typed to tell treatment failure from a new infection.

Treatment failures (including relapses) were 5.8%, 12.7% and 10.7% at the three time points with amoxicillin, against 6.2%, 11.9% and 11.3% with penicillin V.

So once-daily amoxicillin is no worse than twice-daily penicillin V at clearing GABHS from the throat in children, and its once-a-day dosing, low cost and suitable range of activity make it a good choice. Always finish the full course of antibiotics your doctor prescribes.