What Is Clarithromycin?
Clarithromycin is a derivative of erythromycin, which was successfully developed by the Japanese Taisho Corporation in the early 1990s and registered under the trade name Clarith. Thereafter, Taisho transferred its technology to Abbott, USA, for production. Listed in Ireland and Italy in 1990, approved by the FDA in October 1991 as a new class IB drug, with the trade name Biaxin. It was listed in Klacid in Hong Kong, China in 1993, and traded in Europe and Asia under the name Clarence. It has been listed in many countries, the market usage has steadily increased, and it has played an important role in clinical practice. Clarithromycin and its tablets, currently produced dosage forms also include granules, dispersible tablets, sustained-release tablets, injections and dry suspensions [1] .
- Drug Name
- Clarithromycin
- Alias
- Clarithrin; Clarithromycin; 6-0-methylerythromycin A; 6-oxymethylerythromycin; methromycin; methoxyerythromycin; erythromycin;
- Foreign name
- 6-0-MethylerythromycinA, Claricid, Klaricid, 6-0-MethylerythromycinA, Claricid, Klaricid
- Drug type
- Western medicine
- Country of invention
- Japan
- Product name
- Clarith
- Shorthand
- CLARY
- Clarithromycin is a derivative of erythromycin, which was successfully developed by the Japanese Taisho Corporation in the early 1990s and registered under the trade name Clarith. Thereafter, Taisho transferred its technology to Abbott, USA, for production. Listed in Ireland and Italy in 1990, approved by the FDA in October 1991 as a new class IB drug, with the trade name Biaxin. It was listed in Klacid in Hong Kong, China in 1993, and traded in Europe and Asia under the name Clarence. It has been listed in many countries, the market usage has steadily increased, and it has played an important role in clinical practice. Clarithromycin and its tablets, currently produced dosage forms also include granules, dispersible tablets, sustained-release tablets, injections and dry suspensions [1] .
Clarithromycin compounds
Clarithromycin Basic Information
- Chinese name: clarithromycin
- Chinese alias: Clarix; Clarithromycin; 6-0-Methyl erythromycin A; 6-Oxymethyl erythromycin; Methyl erythromycin; Methoxy erythromycin; Cerythromycin; Walker; A Force; Capsis; Kasmaihin; Laihin; Limaixian
- English name: clarithromycin
- English alias: BIAXIN; Claris; te-03; Clarithromycin; 6-0-MethylerythromycinA; Claricid; 6-0-MethylerythromycinA; Claricid; Klaricid
- CAS number: 81103-11-9
- Molecular formula: C 38 H 69 NO 13
- Molecular weight: 747.95300
- Exact mass: 747.47700
- PSA: 182.91000
- LogP: 2.43970
Clarithromycin physical and chemical properties
- Appearance and properties: This product is white or almost white crystalline powder; odorless and bitter. This product is easily soluble in chloroform, soluble in acetone or ethyl acetate, slightly soluble in methanol or ethanol, and insoluble in water.
- Density: 1.18 g / cm 3
- Melting point: 217-220ºC
- Boiling point: 805.5ºC at 760 mmHg
- Flash point: 440.9ºC
- Stability: refrigerated
- Storage conditions: sealed in original container
Clarithromycin Safety Information
- Customs Code: 29419000
- Danger category code: R22
- Safety instructions: S26; S36
- RTECS number: KF4997000
- Dangerous Goods Mark: Xi; Xn
Clarithromycin production method
- 1. Using erythromycin as a raw material, hydrolyze and remove a methyl group on the amino group, and then react with benzyl chloroformate to protect the hydroxyl group and amino group on the tetrahydropyran ring at the 5-position side chain, and then in dimethylene The sulfone and tetrahydrofuran neutralize the methyl iodide, methylate the hydroxyl group at position 6, catalyze hydrogenolysis to remove the protecting group, and methylolate the amino group by reaction with formaldehyde, and finally reduce to methyl, which is clarithromycin. .
2. (1) Preparation of erythromycin A oxime (019-2) Add 50 ml of absolute ethanol and 10.0 g (13.6 mmol) of erythromycin (019-1) to the reaction flask, and add glacial acetic acid dropwise with stirring. After being transparent, 7.0 g (100.0 mmol) of hydroxylamine hydrochloride was added, and the temperature was raised to 50 to 60 o C under an appropriate acid-base buffer system, and the reaction was stirred for 8 to 24 hours. After TLC tracking confirmed that the reaction reached the end point, the reaction was terminated. Cool to At room temperature, the inorganic salts were removed by filtration, and the filtrate was evaporated to dryness under reduced pressure to obtain a white solid. This solid was dissolved in 20 ml of ethyl acetate, and a 4 mol / L NaOH solution was added under stirring to adjust the pH to> = 12. The organic layer was washed 2 to 3 times with an appropriate amount of water, and then concentrated to dryness under vacuum to obtain a white solid, which was dried to constant weight to obtain 019-2 9.98g, with a yield of 99.9%. It contained 019-2 93.5%, of which E-oxime 82.9 %, Z-oxime 10.6%, erythromycin degradation product erythromycin A 8,9-anhydro-6,9-hemiketal ketal <= 2% (HPLC method). 019-2 was recrystallized to obtain 019-2. Pure product, yield 95.6%.
(2) 2 ', 4 "-O-bis (trimethylsilyl) erythromycin A 9-O- (1-ethoxycyclohexyl) oxime [2', 4 ''-Obis (trimethylsilyl) -eryth -romycin A 9-O91-ethoxycyclohexyl] oxime] (019-4) In a reaction flask, add 500ml of acetonitrile, 019-2 50.0g (67mmol), and 15.0g (134mmol) of pyridine hydrochloride, and add 1-ethoxylate with stirring. Cyclohexene (EOCHE) 30.0ml (223mmol), the reaction was stirred at room temperature (28 o C), the reaction solution gradually became clear and colorless, and all were converted into erythromycin A9-O- (1-ethoxy) after 3h Cyclohexyl) oxime (019-3), and then added 1,1,1,3,3,3-hexamethyldisilazane (HMDS) 50.0ml (240mmol), the reaction solution immediately became white turbid. Stir the reaction After 2h, add 4mol / L NaOH solution to adjust to pH> = 10, extract with ethyl acetate (200ml * 2), wash the organic phase with water, saturated brine, and dry with anhydrous MgSO4 overnight. Filter, and evaporate the solvent under reduced pressure. 019-4, mp108 ~ 110 o C.
(3) 2 ', 4``-O-bis (trimethylsilyl) 6-O-methylerythromycin A 9-O- (1-ethoxycyclohexyl) oxime [2', 4 '' -Obis (trimethylsilyl) -6-O-methylerythromycin A 9-O- (1-ethoxycyclohexyl) oxime] (019-5). Add 400ml DMSO / THF (1: 1 by volume) and 019-4 (the previous batch) to the reaction flask, stir to dissolve, and then add 6.0ml (96mmol) of iodoform and 6.0g (88mmol) of 82% KOH powder. Stir the reaction at 0 ° C for 1h. Add 200ml of water, extract with ethyl acetate (200ml * 2), dry the organic phase with anhydrous MgSO4, filter, and evaporate the solvent from the filtrate to obtain 019-5, mp127 ~ 129 ° C. Used directly in the next step.
(4) Synthesis of clarithromycin (019) Add 250ml of ethanol and water to the reaction flask, and then add 019-5 (the amount obtained in the previous step), stir and dissolve, add 5.0ml (132mmol) of formic acid under stirring, the number of reactions After hours, TLC tracking showed 6-O-methylerythromycin A 9-O- (1-ethoxycyclohexyl) oxime and 6-O-methylerythromycin A-9-oxime, and then added NaHSO 3 50.0g (480mmol), stirred and heated to reflux, and reacted for 2h. Adjusted to pH> = 10 with 4mol / L NaOH solution, precipitated a white solid 019, and recrystallized with ethanol to obtain fine 019 24.7g, with erythromycin A The total yield is 49.5%, mp222 ~ 225 o C.
Clarithromycin use
- It is a macrolide antibiotic and is used to treat upper and lower respiratory tract infections and subcutaneous soft tissue infections, etc. [2] .
Clarithromycin Pharmacopoeia Standard
Clarithromycin identification
- (1) In the chromatogram recorded under the content determination item, the retention time of the main peak of the test solution should be consistent with the retention time of the main peak of the reference solution.
- (2) The infrared light absorption spectrum of this product should be the same as that of the control ("Infrared Spectroscopy of Pharmaceutical Products" 756), if necessary, take the appropriate amount of the test product and the reference product, dissolve in chloroform and evaporate to dryness at room temperature The residue after vacuum drying should be measured and should be consistent with the map of the reference substance.
Clarithromycin test
- 1 alkalinity
- Take this product, make a suspension solution containing 2mg per 1ml with water-methanol (19: 1) mixed solution, and measure it according to law (Appendix VI H of the second edition of the Pharmacopoeia, 2010 edition), the pH value should be 7.5 ~ 10.0.
- 2 crystallinity
- Take this product and check it according to law (Appendix D of Part Two of the 2010 Pharmacopoeia), and it should meet the requirements.
- 3 related substances
- Take an appropriate amount of this product, add mobile phase to dissolve and dilute it to make a solution containing 1.0mg per 1ml, as a test solution; take a precise amount of 5ml, put it in a 100ml measuring bottle, dilute to the mark with mobile phase, shake well, as Control solution. According to the chromatographic conditions under the content determination item, take 20 l of the control solution and inject it into the liquid chromatograph, and adjust the detection sensitivity so that the peak height of the main component chromatographic peak is about 50% of the full scale. Precisely measure 20 l each of the test solution and the control solution, and inject them into the liquid chromatograph respectively, and record the chromatogram to 4 times the peak retention time of the main component. If there are impurity peaks in the chromatogram of the test solution, the area of a single impurity peak must not be greater than 0.5 times (2.5%) the area of the main peak of the control solution; the sum of the area of each impurity peak must not be greater than 1.2 times (6.0%) of the main peak area of the control solution.
- 4 moisture
- Take this product, add 10% imidazole anhydrous methanol solution to dissolve it, and measure it according to the moisture determination method (2010 edition Pharmacopoeia Part II Appendix M first method A), the moisture content must not exceed 2.0%.
- 5 burning residue
- Take 1.0g of this product and check it according to law (Appendix N of Part Two of the 2010 Pharmacopoeia). The residual residue shall not exceed 0.3%.
- 6 heavy metals
- Take the residue left under the item of burning residue and check it according to law (Appendix H of the second edition of the Pharmacopoeia of 2010 Edition, the second method H), the content of heavy metals must not exceed 20 parts per million.
Clarithromycin determination
- It was determined by high performance liquid chromatography (Appendix VD of Part Two of the Pharmacopoeia, 2010 Edition).
- 1 Chromatographic conditions and system suitability tests
- Octadecylsilane-bonded silica gel as filler; phosphate buffer solution (take 9.11 g of potassium dihydrogen phosphate, dissolve in water and dilute to 1000 ml, add 2 ml of triethylamine, adjust pH to 5.5 with phosphoric acid)-acetonitrile (600: 400) is the mobile phase; the detection wavelength is 210nm; the column temperature is 45 ° C. The number of theoretical plates calculated based on the clarithromycin peak should not be less than 3000; the tailing factor should not exceed 2.0; the resolution of the clarithromycin peak and the adjacent impurity peak should meet the requirements.
- 2 Assay
- Take an appropriate amount of this product, accurately weigh it, add mobile phase to dissolve and quantitatively dilute to make a solution containing about 0.35mg per 1ml. Precisely measure 20l into the liquid chromatograph and record the chromatogram; take another appropriate amount of clarithromycin reference substance. , Same method. Calculate the peak area according to the external standard method, and get [3] .
Clarithromycin Category
- Macrolide antibiotics.
Clarithromycin storage
- Shaded and sealed.
Clarithromycin
- (1) Clarithromycin tablets (2) Clarithromycin capsules (3) Clarithromycin particles
Clarithromycin Drug Description
Clarithromycin pharmacological action
- This product is a 14-membered ring macrolide antibiotic. Antibacterial spectrum and erythromycin,
- Color molecular structure formula (3 photos)
Clarithromycin pharmacokinetics
- This product is stable to gastric acid
- Clarithromycin [4]
Clarithromycin indication
- Mainly used for sensitive bacteria
- Clarithromycin [4]
Clarithromycin dosage
- Adults take 250mg every 12h, for severe patients
- Urticaria [4]
Clarithromycin adverse reactions
- 1. Visible nausea, heartburn, abdominal pain, diarrhea, and headache. Transaminase is elevated temporarily and can be recovered after stopping the drug.
- Clarithromycin [4]
- 2. Elevated ALT, AST, LDH, alkaline phosphatase, and bilirubin (all <1%); leukopenia (<1%), prolonged prothrombin time (1%), and increased BUN (4 %), Increased serum creatinine (<1%), etc.
Clarithromycin Contraindications
- People who are allergic to macrolides, pregnant women, lactating women, severe liver and kidney dysfunction, arrhythmia, bradycardia, prolonged QT interval, iron deficiency heart disease, congestive heart failure and water and electrolyte disorders are prohibited Or be used with caution. This product is mainly metabolized and excreted in the liver, so patients with liver dysfunction, severe renal dysfunction, and the elderly over 65 years of age need to pay special attention to adverse reactions. Gastrointestinal dysfunction and systemic symptoms can occur when overdose, gastric lavage and supportive therapy can be given. Hemodialysis and peritoneal dialysis cannot clear the product, so drugs that have not been absorbed (such as gastric lavage) should be quickly removed and symptomatic treatment should be given. Pregnant women are prohibited (the concentration of this product in animal embryos is 2-17 times that of human serum). Breastfeeding women should be used with caution (feeding should be suspended).
Clarithromycin overdose
- When taking large doses of clarithromycin, you may have gastrointestinal upset. Symptoms due to overdose should be promptly lavaged and appropriately given supportive therapy. There have been no reports of clarithromycin removal by blood or peritoneal dialysis. However, it is necessary to exclude unabsorbed drugs as soon as possible while taking appropriate symptomatic treatment.
Clarithromycin drug interactions
- This product can interfere with the metabolism of carbamazepine, making the latter's blood concentration clear
- Clarithromycin [4]
/ Clarithromycin Preparation / Specifications
- Clarithromycin tablets clarithromycin capsules
Clarithromycin dry suspension
- English name ClarithromycinforSuspension, category Western medicine
- Indication
- For clarithromycin-sensitive bacteria:
- 1. Nasopharyngeal infections: tonsillitis, pharyngitis, and sinusitis.
- 2. Lower respiratory tract infections: acute bronchitis, acute exacerbation of chronic bronchitis, and pneumonia.
- 3. Skin and soft tissue infections: pustulosis, erysipelas, folliculitis, scabies, and wound infections.
- 4. Acute otitis media, mycoplasma pneumoniae pneumonia, urethritis and cervicitis caused by chlamydia trachomatis.
- 5, also used for Legionella infection, or combined with other drugs for the treatment of Mycobacterium avium infection, Helicobacter pylori infection.
- Dosage
- Oral for adults, 250mg once every 12 hours; severely infected 500mg once every 12 hours
- Hemoglobin (2 photos)
- Adverse reactions
- 1. Mainly oral odor (3%), gastrointestinal reactions such as abdominal pain, diarrhea, nausea, vomiting (2% to 3%), headache (2%), and transient increase in serum aminotransferase.
- 2. Allergic reactions may occur. The mild cases are drug rash and urticaria, the severe cases are allergy and Stevens-Johnson disease.
- 3. Occasionally hepatotoxicity, pseudomembranous enteritis caused by Clostridium difficile.
- 4. There have been reports of transient central nervous system side effects, including anxiety, dizziness, insomnia, hallucinations, nightmares, or confusion, but the cause and the relationship between the drugs are still unclear.
- Taboo
- 1. Those who are allergic to this product or macrolide drugs are prohibited.
- 2, pregnant women, lactating women are prohibited.
- 3. Patients with severe liver dysfunction, patients with water and electrolyte disorders, and those taking terfenadine should not use it.
- 4. Certain patients with heart disease (including arrhythmia, bradycardia, prolonged Q-T interval, ischemic heart disease, congestive heart failure, etc.) are disabled.
- Precautions
- 1. This product can be taken orally on an empty stomach, and can be taken with food or milk. Taking it with food does not affect its absorption. 6. Blood or peritoneal dialysis cannot reduce the blood concentration of the product.
- The efficacy and safety of children under 2, 6 months have not been determined. This product is toxic to embryos and fetuses in animal experiments
- Protein [4]
- 3. There is cross-allergy and cross-resistance between this product and erythromycin and other macrolide drugs.
- 4. As with other antibiotics, serious infections caused by fungi or drug-resistant bacteria may occur. At this time, the use of this product needs to be discontinued and appropriate treatment should be adopted.
- 5, liver damage, moderate to severe renal impairment with caution.
- 6. If the renal function is severely damaged (creatinine clearance rate is less than 30ml / min), dosage adjustment is required. The usual dose is 250mg once a day; severely infected patients are given the first dose of 500mg, and the next dose is 250mg twice a day.
- Overdose
- When taking large doses of clarithromycin, you may have gastrointestinal upset. Symptoms due to overdose should be promptly gastric lavage and appropriate supportive care should be given.
- interaction
- 1. Macrolide antibiotics can change the metabolism of terfenadine and increase its blood concentration, leading to arrhythmias such as ventricular tachycardia, ventricular fibrillation and congestive heart failure. 2. This product slightly affects the metabolism of aminophylline and theophylline in the body. Generally, the dosage of the latter does not need to be adjusted, but the blood concentration needs to be monitored when the dosage of aminophylline and theophylline is too large.
- 3, combined with fluconazole will increase the blood concentration of the product.
- 4. This product is used in combination with HMG-CoA reductase inhibitors (such as lovastatin and simvastatin), and there are very few reports of rhabdomyolysis.
- 5. The combination of this product with cisapride and pimozide will increase the blood concentration of the latter, leading to prolonged Q-T interval, arrhythmia such as ventricular tachycardia, ventricular fibrillation and congestive heart failure. Combination with astemizole will lead to prolonged Q-T interval, but without any clinical symptoms.
- 6. This product can slightly increase the blood concentration of carbamazepine. When the two are combined, the latter should be monitored for blood concentration.
- 7. The combination of this product with digoxin will cause the blood concentration of digoxin to increase, and blood concentration monitoring should be performed.
- 8. Adults with HIV infection take this product and Zidov at the same time at the same time. This product will interfere with the absorption of the latter and reduce the steady-state blood concentration. The time of taking should be staggered.
- 9. In combination with ritonavir, metabolism of this product will be significantly inhibited, so when the daily dose of this product is greater than 1g, it should not be used in combination with ritonavir.
- 10. Similar to other macrolide antibiotics, this product will increase the serum concentration of drugs that need to be metabolized by the cytochrome P450 system (such as astemizole, warfarin, ergot alkaloids, triazolam, midazolam (E.g., cyclosporine, omeprazole, ranitidine, phenytoin, bromocriptine, alfentanib, hysopytol, propidamine, lovastatin, tacrolimus, etc.).
- preparation
- 1g: 0.125g 2g: 0.125g 2g: 0.25g
Clarithromycin Granules
- Indication
- For clarithromycin-sensitive bacteria: 1. Nasopharyngeal infections: tonsillitis, pharyngitis, sinusitis. 2. Lower respiratory tract infections: acute bronchitis, acute exacerbation of chronic bronchitis, and pneumonia. 3 Skin and soft tissue infections: impetigo, erysipelas, folliculitis, scabies, and wound infections. 4 Acute otitis media, mycoplasma pneumoniae pneumonia, urethritis and cervicitis caused by chlamydia trachomatis. 5. It is also used for Legionella infection, or in combination with other drugs for the treatment of Mycobacterium avian infection and Helicobacter pylori infection.
- Adverse reactions
- 1. There have been reports of transient central nervous system side effects, including anxiety, dizziness, insomnia, hallucinations, nightmares, or confusion, but the cause and the relationship between the drugs are still unclear.
- 2. Allergic reactions may occur, with mild cases being drug rash and hives, and severe cases being allergies and Stevens-Johnson disease.
- 3 Occasionally hepatotoxicity, pseudomembranous enteritis caused by Clostridium difficile.
- 4 There were mainly oral odor (3%), gastrointestinal reactions such as abdominal pain, diarrhea, nausea, vomiting (2% to 3%), headache (2%), and transient increase in serum aminotransferase.
- Taboo
- 1. Those who are allergic to this product or macrolides are contraindicated.
- 2. Banned during pregnant and lactating women.
- 3 Patients with severe liver dysfunction, patients with water and electrolyte disturbances, and those taking terfenadine forbidden.
- 4 Certain heart diseases (including arrhythmia, bradycardia, prolonged Q-T interval, ischemic heart disease, congestive heart failure, etc.) are contraindicated.
- Precautions
- liver damage, moderate to severe renal impairment with caution.
- If renal function is seriously impaired (creatinine clearance rate is less than 30ml / min), dosage adjustment is required. The usual dose is 250mg once a day; severely infected patients are given the first dose of 500mg, and the next dose is 250mg twice a day.
- There is cross-allergy and cross-resistance between this product and erythromycin and other macrolide drugs.
- As with other antibiotics, serious infections caused by fungi or resistant bacteria may occur. At this time, the use of this product needs to be discontinued and appropriate treatment should be taken at the same time.
- This product can be taken orally on an empty stomach, or taken with food or milk. Taking it with food does not affect its absorption. 6. Blood or peritoneal dialysis cannot reduce the blood concentration of the product.
- The efficacy and safety of children under 6 months have not been determined. In animal experiments, this product has toxic effects on embryos and fetuses. At the same time, this product and its metabolites can enter breast milk, so pregnant women and lactating women are prohibited. Elderly people are tolerant to young people.
- Overdose
- When taking large doses of clarithromycin, you may have gastrointestinal upset. Symptoms due to overdose should be promptly gastric lavage and appropriate supportive care should be given.
Clarithromycin treatment cases
- Nongonococcal urethritis is mainly caused by chlamydia trachomatis (CT) and mycoplasma urealyticum (Uu), which can be infected individually or in combination. We applied clarithromycin in 201 cases of non-gonococcal urethritis from May 2000 to January 2002, and achieved satisfactory results. The report is as follows.
- Materials and Methods
- 1 case selection All patients were outpatients, no serious visceral diseases, no history of allergies to macrolides; aged 18 to 52 years, average 26.0 ± 4.8 years; 102 males and 99 females; duration The shortest is 6 days, the longest is 1.5 years; there is a history of extramarital sex life before the onset, or the spouse has a history of non-gonococcal pathogen infection. The main manifestations in men are urinary tract discomfort, itching, tingling, or burning sensation, urethral mouth swelling or secretions, sometimes mild and severe; females are mainly manifested as itching of the vulva, increased vaginal discharge, cervical congestion, edema or erosion [1]. Neisseria gonorrhoeae smears or cultures were negative. All patients had not been treated with medication from onset to examination.
- Specimen collection
- Urinary tract secretions were taken from men before and after treatment, and cervical secretions were taken from women. Use a sterile cotton swab to extend into the urethra or cervix 2 to 3 cm, stay for 10 to 30 seconds, slowly rotate 2 times and remove the cotton swab containing columnar epithelial cells.
- Reagents and methods
- CT detection and Uu culture of CT were performed. Among 201 cases, 59 were CT positive, 142 were Uu positive, and 29 were dual infections of CT and Uu.
- treatment method
- Limai first took 250 mg orally twice a day for 15 consecutive days, and rechecked after discontinuation.
- Efficacy determination
- The standard cure is that the symptoms and signs completely disappear, and the pathogen detection is negative. The marked effect is the negative conversion of the pathogen (1 type of negative conversion in the combined infection), but one of the symptoms and signs still does not return to normal. It is effective for the improvement of the condition, but the pathogen is still not negative. Ineffective means that the condition does not improve after treatment, and the pathogen detection is negative.
- Clarithromycin
- Clinical effect: 120 cases (59.7%) were cured clinically, 68 cases (33.8%) were markedly effective, 10 cases (4.98%) were effective, 3 cases (1.49%) were ineffective, and 188 cases (93.5%) were total effective (healed + markedly effective), There was no significant difference in clinical efficacy between male and female patients (2 = 0.211, P> 0.05).
- Pathogen detection of 126 cases with Uu positive, 117 cases with negative conversion after treatment (92.9%); 75 cases with CT positive, 70 cases with negative conversion after treatment (93.3%); total negative conversion rate of 93.0%, negative conversion with two pathogens There was no significant difference in the rate (2 = 0.412, P> 0.05).
- Observation of adverse reactions During the treatment, 5 cases (2.49%) experienced gastrointestinal reactions such as nausea, vomiting, and abdominal discomfort, and 8 cases (3.98%) developed phlebitis. After hot compress and symptomatic treatment, no relay treatment was performed. The time returned to normal, and the incidence of side effects was 6.47%.
- Clarithromycin
- Clarithromycin (Limaixian) is a new generation of semi-synthetic macrolide antibiotics. It binds to the ribosomal 50s subunit of bacterial cells and inhibits the synthesis of bacterial proteins. Bacteria, negative bacteria, and anaerobic bacteria all have strong antibacterial effects. The antibacterial activity against chlamydia and mycoplasma infection is the strongest among macrolide antibiotics. The activity of clarithromycin against Chlamydia trachomatis in vitro is 7-10 times that of erythromycin and 4 times that of doxycycline. The 14-hydroxyl product produced by its metabolism in the body has biological activity, and its antibacterial spectrum is the same as that of clarithromycin itself, and their antibacterial activity in vivo is greatly improved than in vitro.
- Clarithromycin is 800 times more stable than erythromycin. It is stably absorbed in gastric acid, and is quickly distributed to all tissues and fluids of the body. It has higher concentrations in the urogenital system and skin and soft tissues. Oral 250mg, its bioavailability is about 50%, and human plasma protein binding rate can reach 70%. It is widely distributed in the body and high in tissue concentration. Its main metabolite, 14-clarithromycin, still has strong antibacterial activity. At a dose of 250 mg twice daily, the plasma concentration of the drug reaches a stable peak within 2 to 3 days. State, excreted from the urine within 5 days, accounting for 36% of the dose, which is significantly higher than the average level of other macrolides.
- Clarithromycin tablets 250mg 2 times a day, at a stable concentration, its elimination half-life is 3.5 hours, and its active metabolite 14 hydroxyclarithromycin is 4.7 hours, with a long half-life, 1 tablet every 12 hours, thereby improving the patient Convenience and compliance. From the treatment results, clarithromycin has a positive effect on non-gonococcal urethritis, with a total effective rate of 93.5% and a pathogenic negative conversion rate of 93.0%. Clarithromycin has the advantages of good curative effect, short course of treatment, and low frequency of administration. It is safe, has fewer side effects, and is available for clinical application. The adverse reactions should be observed during clinical use.