Antibiotics and Antibiotic Resistance

Different Types of Antibiotics and their Applications

Antibiotics, also known as antibacterials, are types of medications that destroy or slow down the growth of bacteria. In 1929, Alexander Fleming identified penicillin, the first chemical compound with antibiotic properties. Some of the common antibiotics are Penicillins, Cephalosporins, Carbapenems, Macrolides, Aminoglycosides, Quinolones, Sulfonamides and, Tetracyclines etc. General principles of antibiotic prescribing are use: First-line antibiotics first, Reserve broad spectrum antibiotics for indicated conditions only, prescribe antibiotics for bacterial infections if Symptoms are significant or severe.

The antibiotics market generated sales of US$42 billion in 2009 globally, representing 46% of sales of anti-infective agents (which also include antiviral drugs and vaccines) and 5% of the global pharmaceutical market¹. However, the antibiotics market is maturing; it showed an average annual growth of 4% over the past 5 years, compared with a growth of 16.7% and of 16.4% for antiviral drugs and vaccines, respectively.

The cephalosporin class of antibiotics is the largest in terms of sales, generating $11.9 billion in 2009, led by sales of the latest generation of drugs in this class (cefcapene (Flomox; Shionogi), ceftriaxone (Rocephin; Roche) and cefuroxime (Zinnat; GlaxoSmithKline). This class represents 28% of the total antibiotic market, and sales showed a growth of 3.4% over the past 5 years. With sales of $7.9 billion and 19% of the antibiotic market share in 2009, the second largest drug class is the broad-spectrum penicillins, which showed a growth of 5% between 2005 and 2009. The third largest drug class — the fluoroquinolones — had sales of $7.1 billion in 2009, accounting for 17% of the antibiotic market in 2009, and also showed an average growth of 5% between 2005 and 2009. By contrast, as generic versions of an increasing number of macrolides — which had $4.8 billion in sales in 2009 — became available, sales of this class declined by 5% between 2007 and 2009. Overall, the rate of patent expiry of leading antibiotics in the market is set to increase, with several of the current top-selling products facing patent expiry between 2010 and 2016. These include levofloxacin (Levaquin; Johnson & Johnson), moxifloxacin (Avelox; Bayer/Merck) and linezolid (Zyvox; Pfizer), which are expected to lose patent protection in 2011, 2014 and 2016, respectively.