Comparative study of amoxycillin and amoxycillin/clavulanic acid in lower respiratory infections

A comparison of oral amoxycillin (500 mg tds) with amoxycillin/clavulanic acid (Augmentin; 750 mg tds) for 7 to 10 days was completed in 76 patients with lower respiratory infection. In another 9 patients, intravenous Augmentin alone was administered (1.2 g 8 hourly) for 3 days followed by oral doses as above for 7 days. In 50 (59%) patients the underlying chronic lung disease was bronchiectasis. Clinical improvement (1 + or more) was seen in 66% with amoxycillin, 60% with oral Augmentin and 56% with IV Augmentin. For radiographic improvement the respective figures were 47, 53 and 44 per cent. Bacteriologically, elimination was seen in 8% with amoxycillin and 45% with Augmentin (P less than 0.01), while partial success was seen in 16 and 24 per cent respectively. While for gram positive organisms, both drugs were similar in efficacy, for gram negative strains the overall success was 27% with amoxycillin and 67% with Augmentin. The main organisms isolated were Str pneumoniae (12), Klebsiella (41), Pseudomonas (21), E coli (9), Haemophilus (7) and Staph aureus (6). For bacteriologic sensitivity and consequent success, Augmentin may be superior in respiratory infections.