MACROLIDES

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MACROLIDES :

M A C R O L I D E S THIS PPT IS CONTRIBUTED BY SAIKUMAR 1 REVOLUTIONPHARMD.COM

INTRODUCTION::

INTRODUCTION: Macrolide antibiotics are so named as they possess a macrocyclic lactone usually having 12 to 17 atoms SOURCE: These are produced by streptomyces species and the products of actinomycetes 2 REVOLUTIONPHARMD.COM

Common Structural Features::

Common Structural Features: 5 common chemical features they are A macro cyclic lactone, usually having 12 to 17 atoms A ketone group 3 REVOLUTIONPHARMD.COM

PowerPoint Presentation:

One or two aminosugars linked to the nucleus. A Neutral sugar linked either to amino sugar or to lactone ring The presence of the dimethyl amino moiety on the sugar residue, which explains the basicity of these compounds and consequently formation salts. 4 REVOLUTIONPHARMD.COM

SPECTRUM OF ACTIVITY::

SPECTRUM OF ACTIVITY: active against most species of gram They are generally (+) bacteria both cocci and bacilli . The antibacterial spectrum of activity of the more potent macrolides resembles that of pencillin. They also exhibit useful effectiveness against gram (-) cocci, specially Neisseria Species 5 REVOLUTIONPHARMD.COM

MECHANISM OF ACTION::

MECHANISM OF ACTION: 6 REVOLUTIONPHARMD.COM

PHYSICAL PROPERTIES::

PHYSICAL PROPERTIES: Occurs as crystalline powders. Water insoluble molecules. stable in aqueous solutions at or below room temperature. Unstable in acidic conditions and forms internal cyclic ketal. 7 REVOLUTIONPHARMD.COM

CHEMICAL PROPERTIES: :

CHEMICAL PROPERTIES: Macrolides are stable in aqueous solutions at or below room temperature. Macrolides are unstable under acidic conditions &undergo an intramolecular reactions to form an inactive cyclic ketone . 8 REVOLUTIONPHARMD.COM

Chemical Instability Of Macrolides::

Chemical Instability Of Macrolides: 9 REVOLUTIONPHARMD.COM

STRUCTURAL ACTIVITY RELATIONSHIP:

STRUCTURAL ACTIVITY RELATIONSHIP As macrolide are unstable in acidic pH,a no. of strategies have been utilised to improve the acidic stability of erythromycin. The addition of hydroxylamine to the ketone to form oxime e.g. roxithromycin 10 REVOLUTIONPHARMD.COM

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alteration of c-6 hydroxyl group : nucleophilic functionality which initiates erythromycin degradation. The azalides (azithromycin) are semi-synthetic 15-membered congeners in which a nitrogen atom has been introduced to expand a 14-membered precursor- leads to an extended spectrum of action . 11 REVOLUTIONPHARMD.COM

PHARMACOKINETIC ASPECTS::

PHARMACOKINETIC ASPECTS: These are administered orally Erythromycin can also be given parenterally, through intravenous injections. These diffuse readily into most tissues but do not cross the BBB & poor penetration into synovial fluid . 12 REVOLUTIONPHARMD.COM

Therapeutic Agents Of Macrolides: Erythromycin::

Therapeutic Agents Of Macrolides : Erythromycin : 13 REVOLUTIONPHARMD.COM

Source::

Source: Isolated from streptomyces erythreus Physical properties : Yellow to white crystalline powder Soluble in alcohol, slightly soluble in water Stable at neutral PH Dosage forms : Oral and topical dosage forms Enteric coted and delayed realese dosage forms 14 REVOLUTIONPHARMD.COM

Drug interactions::

Drug interactions : Anticoagulants Benzodiazepines Cyclosporine Antihistaminic drugs These agents potentiate the action of erythromycin Adverse effects : Abdominalcramps Epigastric distress Jaundice Transient deafness 15 REVOLUTIONPHARMD.COM

PowerPoint Presentation:

USES: It is used to treat The upper part of the respiratory tract infections, Mycoplasma pneumonia Gonorrhoea. It is a good choice for penicillin-sensitive cases 16 REVOLUTIONPHARMD.COM

Therapeutic agents of erythromycin :

Therapeutic agents of erythromycin Erythromycin ethylsuccinate Prodrug with more lipophilicity- longer duration of action Erythromycin estolate A lipid soluble,acid stable prodrug with better oral absorption Erythromycin gluceptate A water-soluble salt of glucoheptanoic acid for parentral dosage forms Erythromycin lactobionate Erythromycin salt meant for parentral usage 17 REVOLUTIONPHARMD.COM

Clarithromycin Clarithromycin Semisynthetic derivative of erythromycin obtained by selective methylation at c-6 position: 6-Methyl ether of erythromycin:

Clarithromycin Clarithromycin Semisynthetic derivative of erythromycin obtained by selective methylation at c-6 position: 6-Methyl ether of erythromycin 18 REVOLUTIONPHARMD.COM

PowerPoint Presentation:

Advantages: Cannot undergo cyclic ketal formation, so doesn’t cause cramp in GI. Higher blood concentrations. More lipophyl. Lower doses with less intervals USES: Effective against Borrelia burgdorferi, mycobacterium aviumcomplex 19 REVOLUTIONPHARMD.COM

Azithromycin:

Azithromycin Nitrogen containing 15-membered lactone ring macrolides(azalides) Stable under acidic conditions, because it doesn’t form cyclic ketal. 20 REVOLUTIONPHARMD.COM

PowerPoint Presentation:

USES: In the treatment of urogenital infections caused by N. gonorrhoeae and Chlamydia trachomatis . Widely prescribed for the treatment of respiratory tract infections. More active against gram(-)bacteria. 21 REVOLUTIONPHARMD.COM

ROXITHROMYCIN: :

ROXITHROMYCIN: Semi-synthetic 14-membered ring macrolide antibiotic in which the erythronolide lactone ring has been altered to prevent inactivation in the milieu. 22 REVOLUTIONPHARMD.COM

PowerPoint Presentation:

USES: Active against both gram(+) & gram(-) Treatment of skin, dental and genital infections Treatment of upper and lower respiratory tract infections. 23 REVOLUTIONPHARMD.COM

REFERENCES::

REFERENCES: S.N.Pandeya,Textbook of medicinal chemistry Rama Rao Nadendla,Medicinal chemistry Sri Ram, Medicinal chemistry The Mechanism of Action of Macrolides, and Lovmar and Måns Ehrenberg . Keicho N, Kudoh S (2002). "Diffuse panbronchiolitis: role of macrolides . Lopez-Boado YS, Rubin BK (2008). "Macrolides as immunomodulatory therapeutic agents. Curr Opin Pharmacol. 24 REVOLUTIONPHARMD.COM

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