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Галерея диаграмм связей Synthetic antibacterial drugs
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Synthetic antibacterial drugs
This is a mind map about synthetic antibacterial drugs, including quinolones, Sulfonamides, others, etc. Drugs with antibacterial activity synthesized through artificial methods are used to prevent and treat bacterial infectious diseases.
Отредактировано в 2024-03-20 21:04:56
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Synthetic antibacterial drugs
Quinolones
Classification
first generation
Nalidixic acid and Piromidic acid, etc.
It only has antibacterial effects against Escherichia coli, Shigella dysenteriae, Klebsiella spp., and a small number of Proteus bacteria.
second generation
Piperic acid, Cinoxacin and Miloxacin, etc.
The antibacterial spectrum has been expanded, and it also has certain antibacterial effects on Enterobacter, Citrobacter, Pseudomonas aeruginosa, and Serratia.
Third Generation
Ofloxacin, Perfloxacin, Enoxacin, Ciprofloxacin, norfloxacin, etc.
It also has antibacterial effects on Gram-positive bacteria such as Staphylococcus aureus, and its antibacterial effect on some Gram-negative bacteria is further enhanced.
Fourth Generation
Gatifloxacin and moxifloxacin.
The antibacterial activity is enhanced against Gram-positive bacteria, the effect against anaerobic bacteria including Bacteroides fragilis is enhanced, and the effect against typical pathogens such as Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella and Mycobacterium tuberculosis is enhanced. Extended half-life of most products
Antibacterial mechanism
Interferes with bacterial DNA replication (inhibits bacterial DNA gyrase and topoisomerase IV); induces DNA replication errors; inhibits RNA and protein synthesis
Antibacterial spectrum
Broad spectrum powerful bactericidal drug
Especially effective against Gram-negative bacilli, including Pseudomonas aeruginosa (ciprofloxacin has the strongest effect)
It is most effective against some Gram-positive bacteria, such as Staphylococcus aureus. Levofloxacin is the strongest
Cipro, levofluoride, etc. are also effective against Mycobacterium tuberculosis, Chlamydia, Mycoplasma and anaerobic bacteria.
New fluoroquinolones have enhanced activity against Gram-positive bacteria
internal processes
Absorption (good oral absorption, iron, calcium and magnesium ions affect absorption)
The plasma protein binding rate is low and widely distributed, and the lung, kidney, sputum, urine, bile, feces, and prostate are medium and high.
Can enter bones and joints
Pefloxacin is mainly metabolized by the liver and excreted in bile; more than 80% of ofloxacin, levofloxacin, lomefloxacin and gatifloxacin are excreted unchanged through the kidneys. Other drugs are eliminated by the liver and kidneys
Metabolic excretion ( )t 1/2 is long, 3.5 ~ 7 h
① Structure-activity relationship: Antibacterial activity ↑ Antibacterial spectrum ↑, central nervous system toxicity; lipid solubility ↑, photosensitivity; hepatotoxicity and cardiotoxicity ② Antibacterial spectrum: broad-spectrum and powerful bactericidal (levofloxacin has the strongest effect on Gram-positive bacteria) ③ Resistance mechanism: The affinity of the target mutation decreases, the permeability of the cytoplasmic membrane decreases, and active efflux↑ ④ Adverse reactions: Floxacin will damage cartilage. Do not taste it if you are under 18. It may damage the stomach due to mental poisoning. Be careful not to see the light.
⑦Clinical application: Urogenital tract infections (ciprofloxacin and β-lactams are both the first-choice drugs); respiratory system infections (the combination of levoflumox and vancomycin is the first-choice drug for the treatment of highly penicillin-resistant pneumonia) Streptococcal infections. It can replace macrolides for mycoplasma, chlamydia, and legionella infections); intestinal infections and typhoid fever (the first choice for the treatment of acute and chronic bacillary dysentery and toxic bacillary dysentery caused by Shigella. For infections caused by Salmonella For typhoid or paratyphoid, fluoroquinolones or ceftriaxone are the first choice (for Pseudomonas aeruginosa, ciprofloxacin is the first choice); radical treatment of nasopharyngeal carriers of meningococcal meningitis; severe infections in children; bone, joint and soft tissue infections; abdominal biliary tract infections and Pelvic infection: It needs to be combined with anti-anaerobic drugs such as metronidazole. Moxifloxacin can be used as a single drug to treat mild cases; some varieties can be used in combination with other drugs as a second-line drug for the treatment of drug-resistant Mycobacterium tuberculosis and other mycobacterial infections.
⑧Contraindications and drug interactions: It is forbidden for pregnant women with allergies and breastfeeding infants and young children; it should be used with caution in patients with mental illness and epilepsy, and it should not be used routinely in children; Metal ions of antacids reduce their bioavailability; enoxacin, ciprofloxacin, etc. inhibit the metabolism of theophylline in the liver (ofloxacin does not have this effect); nonsteroidal anti-inflammatory drugs increase their central toxic reactions; Appropriate dose reduction for patients with reduced renal function: ofloxacin, enoxacin
Norfluro (Coward), Fluro (Florence); Cipro (Potato Pancake); Oxofuride; Spamoxil (Little Japan is fighting); Gatigare There was a coward who ate a potato pancake in Florence, then looked up at the sky and held his chin, remembering that when he was fighting with the Japanese, he blew them up with two grenades.
Sulfonamides
① Antibacterial spectrum: G G- (meningococci) are effective; the most sensitive (group A pneumonia, meningococci, plague Yernoka); sulfamethoxazole SMZ is effective against typhoid bacilli, and sulfadiazine silver SD-Ag is effective against Pseudomonas aeruginosa Bacilli are effective ② Antibacterial mechanism: Affects folic acid metabolism; sulfonamides compete with PABA for dihydrofolate reductase, and trimethoprim inhibits dihydrofolate reductase → sulfonamide + trimethoprim (enhances the antibacterial effect, expands the antibacterial spectrum, and delays drug resistance) ③Resistance mechanism: Intrinsic resistance (membrane ↓, direct use of existing folic acid in the environment); acquired resistance (chromosome mutation to synthesize excess PABA, Escherichia coli produces low-affinity dihydrofolate pteridase; plasmid-mediated acquisition Plasmid of drug-resistant dihydrofolate pteridase); congeneric cross-resistance ④In vivo process: Complete absorption and wide distribution; plasma protein binding rate SD25% SMZ86%; SD can pass through the BBB and placenta; hepatic acetylation metabolism and renal excretion; high solubility in alkaline urine and easy crystallization in acidic urine ( Alkalinize urine to promote excretion) The solubility of the acetyl compound is lower than that of the parent drug. ⑤Drug interactions: High plasma protein binding rate → Pay attention to reducing the dosage when combined with oral hypoglycemic drugs coumarins, especially the anti-tumor drug methotrexate. So does aspirin.
⑤Adverse reactions: Urinary system and kidney damage → alkalize urine, drink more water to promote excretion, and check urine regularly; allergy - exfoliative dermatitis with rash - → contraindicated if there is a history of cross-allergy; blood system WBC aplastic anemia, kernicterus G-6PD in children Deficiency can cause acute hemolytic anemia; CNS reaction - dizziness, headache, inability to concentrate and insomnia; liver damage → hepatic insufficiency is contraindicated; neonates, premature infants, pregnant and breastfeeding women are contraindicated
⑥Clinical application
Systemic infections: short-acting (SIZ- urinary tract infection); long-acting (SMD-use less); medium-acting (SD, SMZ) SD—the first choice for the prevention and treatment of meningococcal meningitis (low protein binding rate) SMZ—combined use of urinary tract, digestive tract and respiratory tract infections with trimethoprim (TMP)
Intestinal infection: SASP is decomposed into sulfapyridine and 5-aminosalicylic acid in the intestine; antibacterial, anti-inflammatory, and immunosuppressive; Treatment of ulcerative colitis, ankylosing spondylitis, arthritis
External infections: SD-Ag and SML-burns, wounds and infections with Pseudomonas aeruginosa; SA-non-irritating, strong penetrating power, treatment of eye diseases
other
Trimethoprim (TMP)
The antibacterial spectrum is similar to sulfonamide SMZ and is a bacteriostatic drug; the antibacterial activity is dozens of times stronger than SMZ, but bacteria are easily resistant to TMP; it is often used in combination with sulfa drugs or certain antibiotics to have a synergistic effect
Compound sulfamethoxazole: SMZ+TMP (5:1); Dipyrimidine tablets=SD+TMP
Furans
Nitrofurantoin
Mainly used for urinary tract infections caused by Escherichia coli, enterococci and staphylococci, such as pyelonephritis, cystitis, prostatitis and urinary tract infections ~ urinary tract infections The antibacterial effect is best when the urine pH is 5.5 → It is highly acidic and cannot be combined with alkaline drugs; it is rapidly destroyed in the blood and has a half-life of 30min➡️cannot be used for systemic infections
Furazolidone (furazolidone)
Intestinal infectious diseases, peptic ulcer. No alcohol → disulfiram reaction
Metronidazole
Antibacterial spectrum: Anaerobic bacteria, Trichomonas, anti-amoebic protozoa, HP (peptic ulcer), Clostridium difficile (pseudomembranous enteritis), Clostridium tetani, Bacteroides fragilis First choice: Treating amebiasis, trichomoniasis and tetanus During medication and within one week of stopping medication, alcoholic beverages are prohibited → Disulfiram reaction
Yang is strong and Yin is not declining, domineering and resisting anaerobic