ciprofloxacin

Activity

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

• Enterobacteriaceae
• Vibrio
• Haemophilus influenzae
• Neisseria gonorrhoeae
• Neisseria menigitidis
• Moraxella catarrhalis
• Brucella
• Campylobacter
• Mycobacterium intracellulare
• Legionella sp.
• Pseudomonas aeruginosa
• Bacillus anthracis - that causes anthrax

Weak activity against:

• Streptococcus pneumoniae
• Chlamydia trachomatis
• Chlamydia pneumoniae

No activity against:

• Bacteroides
• Burkholderia cepacia
• Enterococcus faecium
• Ureaplasma urealyticum

• and others

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.

In cell culture it is used to treat infection with mycoplasma.

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

It is contraindicated in children, pregnancy, and in patients with epilepsy. Dose adjustment or avoidance may be necessary with liver or renal failure.

Ciprofloxacin can cause photosensitivity reactions and can elevate plasma theophylline levels to toxic values. It can also cause constipation and sensitivity to caffeine. Ciprofloxacin is also known to cause swelling of certain joints and cartilage.

Interactions

Quercetin, a flavonoid occasionally used as a dietary supplement may interact with fluroquinolones, as quercetin competitively binds to bacterial DNA gyrase. Some foods such as garlic and apples contain high levels of quercetin. Whether this inhibits or enhances the effect of fluoroquinolones is not entirely clear.^[2]

Contraindications

Metal cations such as aluminium, magnesium, calcium, ferrous sulfate, and zinc are thought to form chelation complexes with fluoroquinolone antibiotics and prevent the drugs from being absorbed. Because of this, avoid taking antacids which contain aluminium, magnesium or calcium with ciprofloxacin. Sucralfate, which has a high aluminium content, also reduces the bioavailability of ciprofloxacin to approximately 4%^[3]. Ciprofloxacin may be taken with meals or on an empty stomach. Ciprofloxacin should not be taken with dairy products or calcium-fortified juices alone, but may be taken with a meal that contains these products.^[4]

Heavy exercise is discouraged, as achilles tendon rupture has been reported in patients taking ciprofloxacin. Achilles tendon rupture due to ciprofloxacin use is typically associated with renal failure.

The toxicity of drugs that are metabolised by the cytochrome P450 system is enhanced by concomitant use of some quinolones. They may also interact with the GABA A receptor and cause neurological symptoms; this is further augmented by certain non-steroidal anti-inflammatory drugs.^[5]

Fluoroquinolones are increasingly contraindicated for patients who have been to S.E. Asia due to the growing prevalance of antibiotic resistance to the class of antibiotics in that region. ^[6]

Dosing

Ciprofloxacin is available in oral tablets (250, 500, 650, and 1000 mg), as well as ready-made infusion bottles (200 and 400 mg). A combination preparation of ciprofloxacin 500 mg and tinidazole 600 mg is marketed under the name Ciplox-TZ® for infections where anaerobes or protozoa together with ciprofloxacin-sensitive aerobes are likely.

Due to its elimination half-life, ciprofloxacin is administered twice daily. No dose adjustments are generally required for mild to moderate renal impairment.

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 situation; 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 2001 anthrax attacks after the destruction of the World Trade Center. Bayer 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.

Ciprofloxacin is the third largest selling molecule in Pakistan pharmaceutical market. It is marketed by numerous companies. In Pakistan, Highnoon Laboratories Ltd. markets the brand under the name "Cyrocin".

Footnotes

1. ^ Drusano GL, Standiford HC, Plaisance K, Forrest A, Leslie J, Caldwell J. Absolute oral bioavailability of ciprofloxacin. Antimicrob Agents Chemother 1986;30:444-6. PMID 3777908.
2. ^ Hilliard JJ, Krause HM, Bernstein JI, Fernandez JA, Nguyen V, Ohemeng KA, Barrett JF. 'A comparison of active site binding of 4-quinolones and novel flavone gyrase inhibitors to DNA gyrase. Adv Exp Med Biol. 1995;390:59-69. PMID 8718602.
3. ^ Spivey JM, Cummings DM, Pierson NR. Failure of prostatitis treatment secondary to probable ciprofloxacin-sucralfate drug interaction. Pharmacotherapy 1996;16:314-6. PMID 8820479.
4. ^ Drug effects of Ciprofloxacin
5. ^ Brouwers JR. Drug interactions with quinolone antibacterials. Drug Saf 1992;7:268-81. PMID 1524699.
6. ^ Fluoroquinolone Resistance in Neisseria gonorrhoeae -- Colorado and Washington, 1995 [1]

External links

• Data sheet for Cipro
• Fluoroquinolone Toxicity Research Foundation querying the overall safety of fluoroquinolones
• Emergency Medicine Magzine a review of ciprofloxacin in relation to other fluoroquinolones