Fluoroquinolones: drugs, indications, contraindications and side effects

In recent years, synthetic antibacterial drugs are increasingly being used to treat various infections . This is due to the fact that many microorganisms develop resistance to antibiotics of natural origin. In addition, infectious diseases are more and more difficult, and it is not always immediately possible to identify the pathogen. Therefore, there is a growing need for broad spectrum antibacterial agents, to which most microorganisms would be susceptible. One of the groups of the most effective drugs with such properties are fluoroquinolones. These preparations are obtained synthetically and are widely known since the 80s of the 20th century. The clinical results of these agents have proved that they are more effective than most known antibiotics.

What is a group of fluoroquinolones

Antibiotics are drugs that have antimicrobial activity and are most often of natural origin. Formally, fluoroquinolones do not apply to antibiotics. These are synthetic drugs derived from quinolones by the addition of fluorine atoms. Depending on their quantity, they have different efficacy and a period of excretion.

Once in the body, the drugs of the fluoroquinolones group are distributed throughout the tissues, getting into the liquid, the bones, penetrating the placenta and the blood-brain barrier, and also into the bacterial cells. They have the ability to suppress the work of the main enzyme of microorganisms, without which the synthesis of DNA ceases. This unique action leads to the death of bacteria.

Since these drugs are quickly distributed throughout the body, they are more effective than most other antibiotics.

Against which microorganisms are active fluoroquinolones

These are preparations of a wide spectrum of action. It is believed that they are effective against the majority of gram-positive and gram-negative bacteria, mycoplasmas, chlamydia, mycobacterium tuberculosis, some protozoa. They destroy intestinal, pseudomonas aeruginosa and hemophilic rod, pneumococcus, salmonella, shigella, listeria, meningococcus and others. Sensitive to them are also intracellular microorganisms, with which it is difficult to cope with other drugs.

Insensitive to these drugs are only different fungi and viruses, as well as pathogens of syphilis.

The advantage of using these drugs

Many severe and mixed infections can cure only fluoroquinolones. Preparations used for this earlier, now increasingly become ineffective. And fluoroquinolones are more easily tolerated by patients, are quickly absorbed, and microorganisms can not yet develop resistance to them. In addition, the drugs of this group have other advantages:

• Destroy bacteria, not weaken them;
• Have a wide range of action;
• Penetrate into all organs and tissues;
• Prevent the development of septic shock;
• Can be combined with other antibacterial drugs;
• Have a long period of excretion, which increases their effectiveness;
• Rarely cause side effects.

What is the effect of fluoroquinolones

Antibiotics are drugs that cause many side effects. And now many microorganisms have become insensitive to such means. Therefore, fluoroquinolones have become an excellent alternative to antibiotics in the treatment of infectious diseases. They have a unique property to stop the reproduction of bacterial cells, which leads to their final death. This can explain the high efficacy of the fluoroquinolone group. The high bioavailability also belongs to the peculiarities of their action. They penetrate for 2-3 hours in all tissues, organs and fluids of the human body. These drugs are mainly taken with urine. And much less often than antibiotics, cause side effects.

Indications for use

Antibacterial drugs of the group of fluoroquinolones are widely used in nosocomial infections, severe infectious diseases of the respiratory tract and the genitourinary system. Even such serious infections as anthrax, typhoid, salmonellosis, are easy to treat. They can replace most antibiotics. Fluoroquinolones are effective for the treatment of such diseases:

• Chlamydosis;
• Gonorrhea;
• Infectious prostatitis;
• Cystitis;
• Pyelonephritis;
• Typhoid fever;
• Dysentery;
• Salmonellosis;
• Pneumonia or chronic bronchitis;
• Tuberculosis.

Instructions for use of these drugs

Fluoroquinolones are most often available in the form of tablets for oral administration. But there is a solution for intramuscular injection, as well as drops in the eyes and in the ears. To obtain the desired therapeutic effect, it is necessary to comply with all the doctor's recommendations for dosage and features of taking medications. Pills must be washed down with water. It is important to maintain the necessary interval between taking two doses. If it turned out that once the drug is missed, you need to take the medicine as soon as possible, but not simultaneously with the next dose.

When taking fluoroquinolone group preparations, it is necessary to follow the doctor's recommendations about their compatibility with other medicines, because some of them can both reduce the antibacterial effect and increase the possibility of side effects. It is not recommended during treatment to stay in direct sunlight for a long time.

Special instructions to receive

Now the most safe bactericidal agents are fluoroquinolones. These drugs are assigned to many categories of patients who are contraindicated in other antibiotics. But there are certain limitations to their application. Fluoroquinolones are prohibited in such cases:

• Children under 3 years, and for some new-generation drugs - up to 2 years, but in childhood and adolescence they are used only in extreme cases;
• During pregnancy and lactation of the child;
• At an atherosclerosis of vessels of a brain;
• With individual intolerance of the components of the drugs.

With the appointment of fluoroquinolones together with antacid agents, their effectiveness is reduced, so a break of several hours between them is needed. If you use these drugs with methylxanthines or iron preparations, then the toxic effect of quinolones increases.

Possible side effects

Of all the antibacterial agents, fluoroquinolones are most easily tolerated. These drugs can occasionally cause only such side effects:

• Abdominal pain, heartburn, intestinal disorders;
• Headaches, dizziness;
• Sleep disorders;
• Convulsions, trembling in the muscles;
• Decreased vision or hearing;
• Tachycardia;
• Impaired liver or kidney function;
• Fungal diseases of the skin and mucous membranes;
• Increased sensitivity to ultraviolet radiation.

Classification of fluoroquinolones

Now there are four generations of drugs of this group. They began to synthesize in the 60s, but they were not known until the end of the century. There are 4 groups of fluoroquinolones depending on the time of appearance and effectiveness.

• The first generation is a drug with low efficacy against gram-positive bacteria. These fluoroquinolones include preparations containing oxolinic or nalidixic acids.
• Second-generation drugs are active against bacteria that are insensitive to penicillins. They also act on atypical microorganisms. Often with severe infections of the respiratory tract and digestive tract, these fluoroquinolones are used. Preparations for this group include: "Ciprofloxacin", "Ofloxacin", "Lomefloxacin" and others.
• Fluoroquinolones of the third generation are also called respiratory, since they are particularly effective against infections of the upper and lower respiratory tract. This is "Sparfloxacin" and "Levofloxacin".
• 4 generation of drugs of this group appeared recently. They are active against anaerobic infections. While only one drug is distributed - "Moxifloxacin".

Preparations 1 and 2 generations of fluoroquinolones

The first mention of the preparations of this group can be found in the 60s of the 20th century. First, fluoroquinolones were used against infections of the genital tract and intestine. Preparations, the list of which is now known only to doctors, since they are almost not used, had low efficiency. This medication is based on nalidixic acid: "Negra", "Nevigramon." These first-generation drugs were called quinolones. They caused many side effects, and many bacteria were insensitive to them.

But studies of these drugs continued, and in 20 years there were fluoroquinolones of 2 generations. They got their names due to the introduction of fluorine atoms into the quinolone molecule. This increased the effectiveness of drugs and reduced the number of side effects. The second generation of fluoroquinolones include:

• "Ciprofloxacin," also known as "Tziprobai" or "Cyprinol";
• Norfloxacin, or Nolitsin.
• "Ofloxacin", which can be purchased under the name "Ofloksin" or "Tarivid."
• "Pefloxacin", or "Abaktal."
• "Lomefloxacin," or "Maksakwin."

Preparations 3 and 4 generations

Studies of these drugs have continued. And nowadays the most effective are fluoroquinolones. The list of preparations of 3 and 4 generations is not yet very large, as not all have yet been clinically tested and approved for use. They have high efficiency and ability to quickly penetrate into all organs and tissues. Therefore, these drugs are used for severe infections of the respiratory tract, urogenital system, digestive tract, skin and joints. These include "Levofloxacin", also known as "Tavanik." It is effective even for the treatment of anthrax. The drugs of the fourth generation of fluoroquinolones include "Moxifloxacin" (or "Avelox"), which is active against anaerobic bacteria. These new drugs are devoid of most of the shortcomings of other drugs, are more easily tolerated by patients and are more effective.

Fluoroquinolones are one of the most effective agents for the treatment of severe infectious diseases. But they can be used only after the appointment of a doctor.