The Online Encyclopedia and Dictionary








3-quinolinecarboxylic acid
CAS number
ATC code
J01MA02, S01AX13, S03AA07
Chemical formula CH18FN3O3
Molecular weight 331.345
Bioavailability  ?
Metabolism  ?
Elimination half-life 4 hours
Excretion  ?
Pregnancy category  ?
Legal status  ?
Routes of administration  ?

Ciprofloxacin is the generic international name for the synthetic antibiotic manufactured and sold by Bayer Pharmaceutical under the brand name Cipro (and other brand names in other markets, e.g. veterinary drugs ), belonging to a group called fluoroquinolones. Ciprofloxacin is bactericidal and its mode of action depends on blocking of bacterial DNA replication by binding itself to an enzyme called DNA gyrase, which allows the untwisting required to replicate one DNA double helix into two. Notably the drug has 100 times higher affinity for bacterial DNA gyrase than for mammalian.

Ciprofloxacin is a broad-spectrum antibiotic that is active against both Gram-positive and Gram-negative bacteria.

Weak activity against:

No activity against:

The major adverse effect seen with use of is gastrointestinal irritation , common with many antibiotics. Because of its general safety, potency and broad spectrum activity, ciprofloxacin was initially reserved as a 'last-resort' drug for use on difficult and drug-resistant infections . As with any antibiotic, however, increasing time and usage has led to an increase in ciprofloxacin-resistant infections, mainly in the hospital setting. Also implicated in the rise of resistant bacteria is the use of lower-cost, less potent fluoroquinolones, and the widespread addition of ciprofloxacin and other antibiotics to the feed of farm animals , which leads to greater and more rapid weight gain, for reasons which are not clear.

Label information

The drug is available for oral and parenteral use. It is used in lower respiratory infections (pneumonias), urinary tract infections, STDs, septicemias, Legionellosis and atypical Mycobacterioses .

It is contraindicated in children, pregnancy, and epilepsy.

Ciprofloxacin can cause photosensitivity reactions and can elevate plasma theophylline levels to toxic values. It can also cause constipation and sensitivity to caffeine.

Dosage in respiratory infections is 500-1500 mg a day in 2 doses.

Cipro is coded as J01MA in ATC classification.

Business aspects

The discovery and development of ciprofloxacin is that rare case of an actual groundbreaking new drug development , opening up an entire new class of antibiotics for further research, development, and marketing. Even more remarkable, it seems to be a case where the first drug discovered of this class remains the 'gold standard' in terms of efficacy, with the other drugs developed by other pharmaceutical companies relegated to 'me-too' status and forced to compete on the basis of lower cost.

Encouraged by the magnitude of this success, as well as the influx of cash, Bayer Pharmaceutical embarked on a plan to remake itself from a minor pharmaceutical manufacturer into a major player in the international pharmaceutical business , with a lock on the antibiotic field. Unfortunately, a combination of the tendency for antibiotics to be viewed as a commodity and prescribed on the basis of lowest cost, Bayer's inability to follow up with another 'blockbuster' discovery, and a general downturn in the international pharmaceutical business forced Bayer into a major downsizing in 2000-2001. Faced with the imminent expiration of its patent rights to ciprofloxacin in the early 2000's and the predictable loss of market share to generic ciprofloxacin, Bayer has resorted to the usual strategy of pharmaceutical companies in such a situaton; focus on the development and patenting of new variations of the old drug (i.e. pediatric ciprofloxacin, intravenous ciprofloxacin, once-a-day ciprofloxacin, etc.), which will have the side effect of extending the patent on the original drug.

"Cipro" became a household word during the anthrax mail attacks after the destruction of the World Trade Center. Unfortunately, Bayer not only took a severe financial blow from the costs involved in rapidly increasing production of the drug to be sold to the government at far below market price, but ironically was then portrayed in the press as 'War Profiteers', rather than contributors to the safety of the public in the "War on Terror".

Last updated: 08-29-2005 00:17:49
Last updated: 08-31-2005 06:13:00