The Secret of Great Health Care
I am starting to sound like a broken record, but there are four generations of quinolone antibiotics. The first-generation quinolones are almost never used and they will not be discussed.
The first quinolone was developed in 1962 - nalidixic acid. It was developed to treat kidney infections. Other first-generation drugs were developed in the 1970’s.
The most popular second-generation quinolone is ciprofloxacin (Cipro). Ofloxacin and norfloxacin are other second-generation quinolones that are sometimes used.
Third-generation quinolones treat a wide variety of infections. Fourth-generation quinolones are rarely used because of significant liver problems, but can cover more infections than the third-generation quinolones.
Quinolones are powerful medications and should be reserved for more serious infections. Few infections in the doctor’s office – pneumonia and urinary tract infections being the most common – use quinolones as a first-line medication.
Quinolones treat a wide range of infections. Common infections that they treat include: urinary tract infections, pneumonia, acute exacerbation of chronic bronchitis and sinus infections.
Second-generation quinolones, in oral form, are used most frequently for urinary tract infections and some infections that are caused by a bacteria called pseudomonas. They are not commonly used for respiratory tract infections.
The third-generation quinolones do not cover infections caused by pseudomonas as well but do cover pneumonia and other respiratory tract infections. The third-generation quinolones are effective for treated sinus infections, pneumonia and urinary tract infection (Moxifloxacin does not work for urinary tract infections).
Fourth-generation quinolones cover many of the same infections as the third generation quinolones but add coverage of anaerobic bacteria. Anaerobic infections commonly occur in the stomach, mouth or vagina.
Moxifloxacin and gatifloxacin treat chronic bronchitis, pneumonia, diabetic foot infection and bone infections. Gatifloxacin can treat urinary tract infections.
One nice feature of quinolones is that they reach equal levels in the blood when given by mouth or by IV.
Some of the drugs in this class come in eye and eardrop form (see chapter on topical antibiotics) for the treatment of bacterial eye infections and outer ear infections.
Quinolones are well-tolerated drugs. Common side effects include:
Serious side effects are rare, but can include:
These drugs should be used cautiously in those with liver disease and the elderly. They should not be used in those with a history of seizures, brain tumor, inflammation the central nervous system or after a stroke.
These drugs are not approved in children, pregnancy and breast-feeding. It is believed that these antibiotics adversely affect the joints and cartilage in those whose cartilage and joints are still developing. This has been shown in animal studies, but this class is sometimes used in humans with cystic fibrosis and cartilage damage has not been seen. Anthrax is the only approved use for quinolones in children.
As a class, there are many considerations about what else is consumed while the patient is on quinolones.
Side effects are made worse when quinolones are combined with: caffeine, non-steroidal anti-inflammatory drugs and theophylline.
Sometimes these medications do not work. This can happen when the drug is taken with high levels of calcium, magnesium, iron or zinc. If you take any of these substances make sure the antibiotic is taken 2 hours before ingesting these substances or 8 hours afterwards.
Calcium and magnesium are found in many foods but are often found in antacids and is some anti-diarrhea medications. Iron is found in pills that people take when they have a certain type of anemia. Zinc may be found in vitamin supplements or even some homeopathic cold remedies (levels are probably to low in cold remedies (Zicam) to have a significant effect, but I still would not recommend taking quinolones with any zinc product).
Other drugs that may interact include: probenecid, cimetidine, warfarin, some seizure drugs and some immunospuppresnat drugs (cyclosporine).
Resistance is becoming a larger problem with this drug. Some cases of strep throat and staphylococcus aureus have developed resistance to quinolones. The use of this drug significantly increases the risk of a future infection with a bacteria that is resistant to quinolones. Resistance has been noticed to strains of streptococcus, staphylococcus and gonorrhea.
Quinolones are very potent medications and should be used only in those who are seriously ill. The overuse of these drugs is contributing to the antibiotic resistance.
These drugs should not be used for unapproved uses such as ear infections, upper respiratory tract infections and acute bronchitis.
Ciprofloxacin (Cipro) is the most popular second-generation quinolone. It is commonly used for urinary tract infections and selected respiratory tract infections. Ciprofloxacin (Cipro) is often used as it has good gram-negative coverage and some gram-positive coverage. Generally, quinolones are more expensive which can limit their use, but ciprofloxacin comes in a generic form and it is not expensive.
Norfloxacin (Noroxin) is another second-generation quinolone that is used for UTIs, prostate infections and some sexually transmitted diseases. It should be taken on an empty stomach and is given 400 mg every 12 hours.
Levofloxacin (Levaquin) is a popular third-generation quinolone. It is used for pneumonia, sinus infections, urinary tract infections, kidney infections and skin infections.
Moxifloxacin (Avelox) can be used for pneumonia, chronic bronchitis exacerbations, sinus infections, skin infections and abdominal infections. It is dosed 400 mg once a day and is used for 5-21 days depending on the type of infection.
Gemifloxacin (Factive) is a third-generation quinolone that is dosed 320 mg once a day. It is used for five days in bronchitis and 5 to 7 days in pneumonia.
