Fleroxacin is a quinolone antibiotic. It is sold under the brand names Quinodis and Megalocin.

Mechanism of action

Fleroxacin is a bactericidal drug that inhibits bacterial

DNA gyrase DNA gyrase, or simply gyrase, is an enzyme within the class of topoisomerase and is a subclass of Type II topoisomerases that reduces topological strain in an ATP dependent manner while double-stranded DNA is being unwound by elongating RNA-poly ...

and

topoisomerase IV Topoisomerase IV is one of two Type II topoisomerases in bacteria, the other being DNA gyrase. Like gyrase, topoisomerase IV is able to pass one double-strand of DNA through another double-strand of DNA, thereby changing the linking number of DNA b ...

. Like other quinolones and fluoroquinolones the compound eradicates bacteria by interfering with DNA replication (bacterial

DNA replication In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the most essential part for biological inheritanc ...

transcription Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including: Genetics * Transcription (biology), the copying of DNA into RNA, the fir ...

repair The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure, and supporting utilities in industrial, business, and residential installa ...

and recombination). Fleroxacin is active against many Gram-positive and Gram-negative bacteria. It is especially active against Shigella species., Salmonella sp.,

Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Esc ...

, Branhamella catarrhalis,

Haemophilus influenzae ''Haemophilus influenzae'' (formerly called Pfeiffer's bacillus or ''Bacillus influenzae'') is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bacter ...

, Neisseria gonorrhoeae,

Yersinia enterocolitica ''Yersinia enterocolitica'' is a Gram-negative, bacillus-shaped bacterium, belonging to the family Yersiniaceae. It is motile at temperatures of 22–29° C (72–84 °F), but becomes nonmotile at normal human body temperature. ''Y. enterocoliti ...

Serratia marcescens ''Serratia marcescens'' () is a species of rod-shaped, Gram-negative bacteria in the family Yersiniaceae. It is a facultative anaerobe and an opportunistic pathogen in humans. It was discovered in 1819 by Bartolomeo Bizio in Padua, Italy.Serra ...

, Staphylococcus aureus,

Pseudomonas aeruginosa ''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aerug ...

Pharmacokinetics

After

oral administration Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are ...

fleroxacin is rapidly and well absorbed from the gastrointestinal tract and shows a good

bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. Ho ...

. The antibiotic is widely distributed throughout the body and in the different biological tissues. In many biologic specimens the levels of fleroxacin are similar to those in plasma, but in bile, nasal secretions,

seminal fluid Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Semen is ...

, lung, bronchial mucosa, and

ovaries The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...

, the drug concentrations are 2-3 times higher than those in plasma. The serum

elimination half-life Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...

, in subjects with normal renal function, is relatively long (9–12 hours), which permits once-daily dosing. Approximately the urinary excretion is 38% of an orally administered dose within 48 h, and in urine is possible detect 8.6% of the N-demethyl metabolite and 4.4% of the N-oxide metabolite. Fleroxacin can penetrate into

milk Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digest solid food. Immune factors and immune-modula ...

of nursing women. As quinolones are known to induce

arthropathy An arthropathy is a disease of a joint. Types Arthritis is a form of arthropathy that involves inflammation of one or more joints, while the term arthropathy may be used regardless of whether there is inflammation or not. Joint diseases can be ...

in juvenile animals, administration of the drug to

breast-feeding Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that brea ...

women cannot be allowed.

Medical uses

Fleroxacin is effective in the treatment of a wide variety of infections, particularly uncomplicated cystitis in women, acute uncomplicated pyelonephritis,

gonorrhea Gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium ''Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Infected men may experience pain or burning with u ...

, bacterial enteritis, traveler's diarrhea,

respiratory tract infections Respiratory tract infections (RTIs) are infectious diseases involving the respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI ...

( including exacerbation of chronic bronchitis).

Adverse effects

In treated patients the most common adverse reactions are gastrointestinal, including

dyspepsia Indigestion, also known as dyspepsia or upset stomach, is a condition of impaired digestion. Symptoms may include upper abdominal fullness, heartburn, nausea, belching, or upper abdominal pain. People may also experience feeling full earlier ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...

, flatulence,

abdominal pain Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a m ...

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...

and sometimes

constipation Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement ...

. Also common disorders affecting the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different de ...

(

itching Itch (also known as pruritus) is a Wikt:sensation, sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of Sensory system, sensory experience. Itch has many similarities to pain, ...

urticaria Hives, also known as urticaria, is a kind of skin rash with red, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and does not leave any long-last ...

rash A rash is a change of the human skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...

phototoxicity Phototoxicity, also called photoirritation, is a chemically induced skin irritation, requiring light, that does not involve the immune system. It is a type of photosensitivity. The skin response resembles an exaggerated sunburn. The involved chemi ...

and

photosensitivity Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light. In medicine, the term is principally used for abnormal reactions of the skin, and two types are distinguished, photoallergy and phototoxicit ...

) and

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all p ...

(

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a common medical c ...

, headache, tremor, paresthesia, impaired sense of taste and smell), psychiatric disorders (alteration of the

sleep-wake cycle A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to ...

state of

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...

, depression, hallucinations and

nightmares A nightmare, also known as a bad dream, Retrieved 11 July 2016. is an unpleasant dream that can cause a strong emotional response from the mind, typically fear but also despair, anxiety or great sadness. The dream may contain situations of d ...

). Fleroxacin and other fluoroquinolones, are known to trigger

seizures An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with l ...

or lower the seizure threshold, due to their inhibitory activity on

GABA receptor The GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid (GABA), the chief inhibitory compound in the mature vertebrate central nervous system. There are two classes of GABA receptors: GABAA and ...

binding. The antibiotic should not be administered to patients with

epilepsy Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...

or a personal history of previous convulsive attacks as may promote the onset of these disorders.

Contraindications

Fleroxacin is contraindicated in patients with a history of

hypersensitivity Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune ...

to the substance or any other member of the quinolone class, or any component of the medicine. Fleroxacin, like other

fluoroquinolones A quinolone antibiotic is a member of a large group of broad-spectrum bacteriocidals that share a bicyclic core structure related to the substance 4-quinolone. They are used in human and veterinary medicine to treat bacterial infections, as we ...

, can cause degenerative changes in weightbearing joints of young animals. The antibiotic should only be used in children when the expected benefits are outweigh the risks.

References

{{QuinoloneAntiBiotics 1,4-di-hydro-7-(1-piperazinyl)-4-oxo-3-quinolinecarboxylic acids Fluoroquinolone antibiotics Fluoroethyl compounds