What Is Lomefloxacin?

The chemical name of lomefloxacin is l-ethyl-6,8-difluoro-1,4-dihydro-7- (3-methyl-1-piperazinyl) -4-oxo-3- Quinoline carboxylic acid, off-white to yellow crystal, molecular formula is C17H19F2N3O3, molecular weight is 351.34800, density is 1.342 g / cm3, melting point is 239-240ºC, boiling point is 542.7ºC at 760 mmHg. It is clinically effective for urinary tract, respiratory and intestinal infections.

Chinese name: Lomefloxacin
Foreign name: Lomefloxacin

CAS number: 98079-51-7
Molecular formula: C17H19F2N3O3
Molecular weight: 351.34800

Introduction to Lomefloxacin Compounds

Lomefloxacin Basic Information

Chinese name

Chinese alias: (+/-)-1-ethyl-6,8-difluoro-1,4-dihydro-7- (3-methyl-1-piperazinyl) -4-oxo-quinoline- 3-carboxylic acid

English name: lomefloxacin

English alias: Lomefloxacinum; LFLX; Lomefloxacine; Maxaquin; Lomefloxacino;

MDL number: MFCD00214312

RTECS number: VB1997500

PubChem number: 24278514

Molecular formula: C ₁₇ H ₁₉ F ₂ N ₃ O ₃

Chemical structure:

Molecular weight: 351.34800

Exact mass: 351.13900

PSA: 74.57000

LogP: 2.18970 ^[1]

Physical and chemical properties of Lomefloxacin

Appearance and properties: off-white to yellow crystals

Density: 1.342 g / cm ³

Melting point: 239-240ºC

Boiling point: 542.7ºC at 760 mmHg

Flash point: 282ºC

Refractive index: 1.547

Stability: Stable if stored at recommended conditions.

Storage conditions: -20ºC ^[1]

Lomefloxacin toxicology data

Acute toxicity ₅₀ mice (mg / kg): 245.6 intravenously;> 4000 orally. ^[2]

Lomefloxacin molecular structure data

1. Molar refractive index: 86.66

2. Molar volume (cm3 / mol): 265.6

3. Isotonic specific volume (90.2K): 698.4

4. Surface tension (dyne / cm): 47.8 ^[2]

5. Polarizability (10-24cm3): 34.35

Computed Chemical Data for Lomefloxacin

1. Hydrophobic parameter calculation reference value (XlogP): None

2.Number of hydrogen-bonded donors: 2

3.Number of hydrogen bond acceptors: 8

4.Number of rotatable chemical bonds: 3

5.Number of tautomers: none

6. Topological molecular polar surface area 72.9

7.Number of heavy atoms: 25

8.Surface charge: 0

9.Complexity: 586

10.Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 1

13. Determine the number of chemical bond stereocenters: 0

14. Uncertain number of chemical bond stereocenters: 0

15. Number of covalent bond units: 1 ^[2]

Lomefloxacin synthesis method

Using 2,3,4,5-fluorobenzoic acid as raw material, chlorinated with sulfoxide to form acid chloride, and then condensed with diethyl ethoxymalonate, and then decarboxylated to form ethyl tetrafluorobenzoyl acetate Then it is condensed with triethyl orthoformate under the action of acetic anhydride to obtain olefinic bonds, reacted with ethylamine to replace ethoxy, and cyclized under sodium hydride to form a quinoline ring derivative, and the ester group is hydrolyzed to a carboxyl group. -Methylpiperazine reaction to give lomefloxacin. ^[2]

Lomefloxacin uses

It is a long-acting quinolone oral antibacterial agent. By inhibiting bacterial DNA gyrase and stopping the growth of bacteria, it exerts antibacterial effect. Broad antibacterial spectrum, high efficiency, safety, stable metabolism and good tolerance. Because there is no cross-effect with theophylline, there is no contraindication to the use of asthma patients, so it is especially suitable for the elderly. It can be used for respiratory infections, sepsis, enteritis, urinary tract infections, gynecological infections, eye and oral infections, and can also prevent infections after surgery. ^[2]

Lomefloxacin pharmacology and toxicology:

Lomefloxacin pharmacological effects:

Lomefloxacin quinolones are broad-spectrum antibacterials. They have bactericidal effects on Gram-negative bacteria, Gram-positive bacteria, and some anaerobic bacteria. The antibacterial effect of piperacic acid-resistant E. coli and bacteria resistant to other drugs is better. Its antibacterial mechanism is to inhibit the activity of bacterial DNA helicase, thereby inhibiting bacterial DNA transcription and replication, and it has bactericidal effect on a variety of Gram-positive and negative bacteria.

Lomefloxacin Toxicology Study:

As with all quinolone drugs, the following phenomena have been observed in Lomefloxacin's animal toxicity tests: Lomefloxacin affects the weight-bearing joints of young animals; when administered in large doses, it can cause central nervous system damage in rodents if it exceeds 272 mg / kg, Dogs and cats have high sensitivity and can cause central damage at lower doses. No renal toxicity was seen in animals and no urine crystals were found in human tests. Lomefloxacin has an effect on plasma globulin in animal tests. See this phenomenon.

Carcinogenicity: Hairless mice are exposed to the sun 5 times every 2 weeks after administration of lomefloxacin for 3.5 hours up to 52 weeks, resulting in phototoxicity. The administration of UV light at the same time produced skin cancer in 16 weeks. In the model using quinolone and UV light at the same time, the skin cancer occurred in the range of 28 to 52 weeks. 92% of the mice given both Lomefloxacin and UV light developed skin squamous cell carcinoma, which was non-metastatic. In this model, rat mice given Lomefloxacin alone developed skin or systemic tumors. The clinical differences between this study and humans are unknown.

Mutagenicity: An in vitro mutagenicity test showed that Lomefloxacin was weakly positive at concentrations> / = 226 g / ml. The results of the other two in vitro mutagenicity tests and two in vivo murine nuclear mutagenicity tests were negative.

Reproductive toxicity: Lomefloxacin does not affect male and female reproduction at 8 times the oral dose. ^[3]

Lomefloxacin pharmacokinetics:

This product is widely distributed in the body and has good tissue penetration. The drug concentration in the skin, sputum, tonsils, prostate, gallbladder, tears, saliva, and gums reaches or exceeds the blood concentration. The elimination half-life is 6 to 7 hours. It is mainly excreted from the urine through the kidneys in the form of the original drug, and about 70% to 80% is excreted from the urine within 48 hours. Probenecid can delay the excretion of lomefloxacin, increase the area under the average curve (AUC) by 63%, increase the average peak time (t _max ) by 50%, and increase the average peak concentration (C _max ) by 4%; May cause toxicity due to the increased blood concentration of this product. ^[3]

Lomefloxacin indications:

For the following infections caused by sensitive bacteria:

1. Respiratory infections: acute exacerbation of chronic bronchitis, bronchiectasis with infection, acute bronchitis, pneumonia, etc.

2. Genitourinary system infections: acute cystitis, acute pyelonephritis, complex urinary tract infections, acute episodes of diffuse urinary tract infections, acute and chronic prostatitis, simple gonorrhea, etc.

3 Abdominal cavity, biliary tract, intestinal tract, typhoid and other infections.

4 Skin and soft tissue infections.

5. Other infections, such as sinusitis, otitis media, and blepharitis. ^[3]

Lomefloxacin Usage and Dosage:

Intravenous infusion; 0.2g each time for adults, diluted in 5% glucose injection or 250ml saline, the infusion time is not less than 60 minutes per 100ml, twice a day, or as directed by a doctor. ^[3]

Lomefloxacin adverse reactions:

1. The common adverse reactions of lomefloxacin are: headache, nausea, vomiting, photosensitivity, dizziness, diarrhea and abdominal pain.

2. Lomefloxacin has observed the following adverse reactions:

Autonomous: increased sweating, thirst, flushing, etc .;

Physical: fatigue, back pain, depression, weakness, etc .;

Cardiovascular: palpitations, hyperactivity, hypertension, hypotension, myocardial infarction, angina pectoris, etc .;

Central nervous system and peripheral nervous system: tremor, dizziness, paresthesia, convulsions, seizures, etc .;

Gastrointestinal tract: indigestion, vomiting, constipation, gastrointestinal bleeding, difficulty swallowing, etc .;

Hematology: purple epilepsy, lymphadenopathy, thrombocytosis, anemia, etc .;

Liver and kidney: elevated serum amino acid transferase and BUN values;

Metabolism: thirst, high blood sugar;

Musculoskeletal: joint pain, myalgia, leg pain spasm;

Ophthalmology: visual abnormalities, conjunctivitis, photophobia, etc .;

Psychiatry: insomnia, neuroticism, hallucinations, depression;

Reproductive system: female: candidiasis, vaginitis, abnormal menstruation, etc .; male: epididymitis, orchitis.

Respiratory system: respiratory infections, rhinitis, pharyngitis, dyspnea, etc.

Skin / allergies: pruritus, rubella, skin loss, etc .; occasionally exudative polymorphic erythema and angioedema;

Special sensation: abnormal taste.

Urethral: Hematuria, crystallized urine, frequent urination, dysuria, anuria, etc. ^[3]

Local: Phlebitis

Lomefloxacin contraindications:

Those who are allergic to this product or other quinolone drugs are contraindicated. ^[3]

Note for Lomefloxacin :

It should be used with caution in patients with impaired renal function or insufficiency of liver function. If used, the liver and renal function should be monitored and the dosage adjusted appropriately.
Patients with previous central nervous system diseases, including those with a history of cerebral arteriosclerosis or epilepsy, should avoid application, and weigh the advantages and disadvantages when indicated.
There are cross-allergic reactions among quinolone drugs, and this product is not suitable for those who are allergic to any kind of quinolone.
Crystalline urine is prone to occur when the patient's urine pH is above 7, so the daily water intake must be sufficient to keep the daily urine volume above 1200-1500ml.
Patients should also pay attention to the following issues:
(1) This product can have moderate to severe photoallergic reactions. Avoid direct or indirect contact with sunlight and ultraviolet light as much as possible during the treatment and within a few days after the treatment.
(2) Avoiding exposure to sunlight for 12 hours after application can reduce phototoxicity caused by lomefloxacin.
(3) If symptoms of phototoxic reaction occur, such as skin burning, redness, swelling, blisters, rash, pruritus, dermatitis, etc., medication should be stopped.
(4) Patients who have experienced phototoxic reactions should avoid exposure to sunlight and ultraviolet light until complete recovery.
(5) Do not take mineral supplements or vitamins containing metals or minerals 2 hours before and after the medication. ^[3]

Lomefloxacin for pregnant and lactating women:

Banned for pregnant and lactating women.

Lomefloxacin for children:

Quinolones can cause lameness due to permanent damage to the load-bearing articular cartilage in dogs, and can also cause joint disease in several other minor animals. Therefore, this product is contraindicated in patients under the age of 18. ^[3]

Lomefloxacin for the elderly:

The drug is mainly excreted through the kidneys, and patients with renal dysfunction have a greater toxic response. Because renal function in elderly patients is prone to weaken, renal function should be monitored.

Lomefloxacin drug interactions:

Theophylline: In clinical studies of long-term use of theophylline, lomefloxacin has no significant effect on theophylline concentration.

Antacids and sucralfate: antacids and sucralfate containing magnesium or aluminum and preparations containing divalent and trivalent ions such as dideoxycreatin can form complexes with lomefloxacin and interfere with the bioavailability of degree.

Caffeine: 200mg of caffeine given to healthy volunteers who have reached steady-state lomefloxacin plasma concentrations did not cause statistically significant differences and changes in clinical pharmacokinetic parameters of caffeine and its main metabolites.

Cimetidine: Cimetidine may interfere with the elimination of other quinolone drugs, leading to an increase in half-life and AUC. The interaction between cimetidine and lomefloxacin has not been studied.

Cyclosporine: Cyclosporine can be combined with other quinolones to increase the serum concentration of cyclosporin. The interaction between cyclosporin and lomefloxacin has not been studied.

Omeprazole: Multiple doses of omeprazole followed by a single dose of lomefloxacin did not cause significant changes in the pharmacokinetic parameters of lomefloxacin (AUC, _Cmax , or _tmax ). Omeprazole Kinematic changes have not been studied.

Phenytoin: phenytoin sodium sustained-release capsules are used in combination with lomefloxacin for 5 days. The pharmacokinetic parameters of phenytoin sodium are AUC, C _max , C _min or t _max . Lomefloxacin may not have a significant effect on the metabolism of phenytoin sodium.

Terfenadine: In a steady-state study of 28 healthy men, terfenadine was used in combination with lomefloxacin, and the pharmacokinetics of terfenadine or lomefloxacin did not change significantly. Warfarin: Quinolones can improve the effect of the anticoagulant warfarin or its derivatives. The combination of these drugs should be closely monitored by prothrombin time or other coagulation tests. However, there was no significant change in the clotting time ratio or the enantiomeric pharmacokinetics of warfarin under the steady-state conditions when warfarin was combined with lomefloxacin.

Urine alkalizing agent can reduce the solubility of this product in the urine, leading to crystalline urine and renal toxicity. ^[3]

Lomefloxacin overdose:

Information on overdose in the body is limited. If the drug is overdose, appropriate supportive care should be given or as directed by your doctor. Blood or peritoneal dialysis has little effect. ^[3]

Lomefloxacin Expert Reviews

Lomefloxacin is a longer-acting third-generation quinolone broad-spectrum antibacterial agent, which has high antibacterial activity against aerobic gram-negative bacteria. It has high antibacterial activity against penicillin-resistant gonococci and enzyme-producing influenza bacilli. Lomefloxacin is used to treat respiratory and urinary system infections with a total effective rate of 93.5%. Lomefloxacin is used to treat respiratory infections with a cure rate of 60% and an effective rate of 85.2%. For urinary system infections, the cure rate is 80.5%. The efficiency is 92.7%; the bacterial clearance rate is 91.2%, and the in vitro antibacterial activity shows that Lomefloxacin has a good antibacterial effect on most Gram-negative and positive bacteria, and in vitro antibacterial against E. coli, Klebsiella pneumoniae and dysentery bacillus. The activity and killing effect in vivo were slightly inferior to ofloxacin and fleroxacin, and the incidence of adverse reactions was 3.7%, which was mainly gastrointestinal reactions with a slight degree. The domestic lomefloxacin collaboration group used tablets and capsules to treat 424 cases of bacterial infections, with effective rates of 89.4% and 90.9%, respectively, and bacteriological clearance rates of 89.6% and 90.6%, respectively. Randomized controlled treatment of 114 cases of respiratory infection and 131 cases of urinary system infection with lomefloxacin, ofloxacin and norfloxacin showed no significant difference in efficacy and safety between lomefloxacin and the latter two. The in vitro antibacterial activity of drugs such as lomefloxacin against 390 clinical isolates was determined. The results showed that lomefloxacin had high antibacterial activity against gram-negative bacilli and gonococci, and also had certain antibacterial effects against staphylococci. Norfloxacin is similar. The first hospital affiliated to West China Medical University applied lomefloxacin capsules for the treatment of 405 cases of acute bacterial infections, including 103 randomized control groups and 199 open test groups, each given 200 mg twice daily for 7 to 14 consecutive days. Results The cure rates of the two Lomefloxacin capsules were 76.7% and 80.5%, the effective rates were 95.1% and 92.2%, the bacteriological clearance rates were 90.2% and 90.9%, and the incidence of adverse reactions was 6.8% and 5.03%. To observe the effect of this product on urinary tract infection, this product and norfloxacin were used to treat 25 and 23 patients with urinary tract infection, respectively. Results The marked effective rates were 80% and 35%, and the total effective rates were 96% and 91%, respectively, because this product has a faster effective time within 2 days after treatment (P <0.01). In addition, it was reported that 101 patients with uncomplicated gonorrhea were randomly divided into two groups, 58 and 43 patients, respectively, and this product or ofloxacin were orally administered. The cure rates of the two groups were 93.1% and 90.7%, respectively; The rates were 96.6% and 93.1%, and the incidences of adverse reactions were 17% and 23%, respectively. The response was slight. ^[4]