MACROLIDES

MACROLIDES C화학적 특성, 용도, 생산

Indications

The macrolide antibiotics clarithromycin and azithromycin have demonstrated in vitro activity against mycobacteria, although they have limited activity against M. tuberculosis. Clarithromycin is four times as active as azithromycin against M. aviumintracellulare in vitro. Azithromycin’s lower potency may be compensated for by its greater intracellular penetration and its two-fold higher tissue levels than plasma levels. Clarithromycin with azithromycin, in combination with other drugs, has gained an important role in the prevention and treatment of MAC in HIVinfected patients.

Antimicrobial activity

The 14-, 15- and 16-membered-ring macrolides share the same antibacterial spectrum, including most Gram-positive organisms, Neisseria spp., Haemophilus spp., Bordetella pertussis, Moraxella catarrhalis and both Gram-positive and Gramnegative anaerobes. They are inactive or poorly active against Enterobacteriaceae and non-fermentative Gramnegative bacteria such as Pseudomonas aeruginosa.

Pharmacokinetics

Erythromycin is characterized by poor water solubility and rapid inactivation by stomach acidity, resulting in widely varying bioavailability after oral administration. Derivatives of erythromycin A have improved pharmacological properties, including bioavailability, gastrointestinal tolerance, higher peak plasma levels, longer apparent elimination plasma halflives and improved tissue concentrations.
Oral absorption is rapid, with plasma peaks varying between 0.4 mg/L (azithromycin) and 11 mg/L (roxithromycin). Maximum concentrations are reached between 0.5 h (rokitamycin) and 3 h (clarithromycin) and are dose dependent.
The apparent elimination half-life varies from 1 h (miokamycin) to 44 h (dirithromycin)： the absolute bioavailability varies between 10% (dirithromycin) and 55–60% (roxithromycin, clarithromycin). The main elimination route is via the bile and feces： a proportion of clarithromycin is excreted via the intestinal mucosa. A substantial part of the administered dose of clarithromycin is eliminated in urine. The long apparent elimination half-lives of roxithromycin, azithromycin and dirithromycin allow them to be administered as single daily oral doses.

Clinical Use

The macrolides retain the classic clinical applications of erythromycin, including activity against Gram-positive cocci and intracellular pathogens such as Legionella, Chlamydia and Rickettsia spp. The improved pharmacokinetic properties and tissue distribution of some semisynthetic compounds may prove useful in more unusual settings such as infections due to mycobacteria (M. avium complex) and protozoa (e.g.Toxoplasma gondii, Entamoeba histolytica, Plasmodium falciparum). Other target infections are chronic gastritis (H. pylori) and borreliosis.

부작용

Macrolides are generally safe and serious adverse events are rare. A notable exception is erythromycin estolate, which is hepatotoxic and may cause severe hepatitis, probably as a result of the mixture of lauryl sulfate and the 2′-propionyl ester. Gastrointestinal complaints (nausea, vomiting, abdominal pain or, less frequently, diarrhea) are most common; they present a problem mainly with erythromycin doses higher than those recommended and are partly due to a hemiketal degradation product that acts on motilin, an intestinal endopeptide.
The semisynthetic 14- and 15-membered-ring macrolides are more acid stable than erythromycin A and are better tolerated.

MACROLIDES 준비 용품 및 원자재

원자재

준비 용품

MACROLIDES 공급 업체

공급자	전화	이메일	국가	제품 수	이점
Sifam Healthcare (p) Ltd	--		India	1	58
ecochem international chemical broker	--	export@ecochem.dk	Europe	6385	66
kemikalieimport	--	Sales@kemikalieimport.dk	Europe	6699	47
A.T.CHEMICAL	--	Jeffreyxu@atchem.net	China	6594	51