Detail about an Antibiotic (AZITHROMYCIN)

The invention of azithromycin the active pharmaceutical ingredient of the antibiotic is the great achievement in the history of science.From the viewpoint of commercialization of research results, it may have been one of the greatest. In addition to contributing to science and to medicine, azithromycin has also brought about an improvement in the quality of life on the global level. 

WHAT IS AZITHROMYCIN?  

Azithromycin is an azalide, a type of macrolide antibiotic means having a macrocyclic lactone ring attached with sugar. It was discovered 1980 by Pliva and approved for medical use in 1988. It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system. The World Health Organization classifies it as critically important for human medicine. 

Formula: C38H72N2O12 

Azithromycin mainly derived from erythromycin, which is the first member of macrolide. It is derived by addition of METHYLATED NITROGEN into the lactone ring.so azithromycin is the modification of erythromycin which has an expanded spectrum, improved pharmacokinetics, better tolerability and drug interaction profiles.  

 SOME PROPERTIES OF AZITHROMYCIN  

• This antibiotic is bacteriostatic in nature and acts by inhibiting protein synthesis of bacteria.  
• These are obtained mainly from actinomycetes genus such as streptomyces.   
• It has best activity against gram negative bacteria & Has less activity against gram positive bacteria as compare to erythromycin.  

• This antibiotic is slowly released from tissue.  
• Its high activity is exerted on respiratory pathogens—Mycoplasma, Chlamydia pneumoniae, Legionella, Moraxella and on others like Campylobacter.  
• It has higher efficiency and lower side effect.  

 LETS SEE THE PHARMACOKINETICS OF AZITHROMYCIN DRUG. PHARMACOKINETICS MEANS WHAT OUR BODY DOES WITH THE DRUGS AFTER ENTERING OUR BODY.  

The pharmacokinetics of azithromycin were examined in man. Mainly Azithromycin is taken orally. After entering the drug into the body, there are some steps— 

1st absorption of the drug,2nd distribution 3rd metabolism & 4th excretion of the drug. 

The remarkable pharmacokinetic properties are acid-stability, larger tissue distribution and intracellular penetration. After entering into the body the drug goes to the stomach for absorption. We all know in stomach HCL is present, acid stability means azithromycin remains stable & able to work in presence of acid   

After absorption it goes to the plasma & attached to the plasma proteins for distribution.  The bioavailability of azithromycin is approximately 37% in humans . Bioavailability, means the proportion of the unchanged drug that enters into the blood circulation. Through the plasma it reaches to its target point where the drug actually works. Concentration of azithromycin in most tissues exceeds that in plasma. Particularly high concentrations are attained inside macrophages and fibroblasts; volume of distribution is ~30 L/kg. Then the drug is slowly released from the intracellular sites contributes to its long terminal t½ means halflife of this drug that is>50 hr. In case of azithromycin, it is partially metabolised by liver & the maximum unchanged drug largely excreted in bile, renal excretion is ~ 10% . 

NOW DISCUSS ABOUT THE PHARMACODYNAMICS. AS PHARMACOKINETICS, PHARMACODYNAMICS IS ALSO A NEW TERM FOR US. THERE IS A LITTLE BIT DIFFERENCE BETWEEN THE TWO TERMS. PHARMACODYNAMICS MEANS AFTER ENTERING OUR BODY WHAT DRUGS DO.  

Azithromycin inhibits bacterial protein synthesis by reversibly binding to the 50S ribosomal subunit & suppression of RNA dependent protein synthesis by inhibition of translocation of MRNA. Initial, stimulatory effects of azithromycin on immune and epithelial cells by involving interactions with phospholipids and Erk1/2. 

LETS SEE SOME POPULAR BRAND NAMES OF AZITHROMYCIN WITH THEIR COMPANY NAMES — 

At first the company Pliva patented the drug in 1981 & the dose was 250mg. 

 In 1986, Pliva and Pfizer signed a licensing agreement, which gave Pfizer exclusive rights for the sale of azithromycin in Western Europe and the United States. Pliva put its azithromycin on the market in Central and Eastern Europe under the brand name Sumamed in 1988. 

 Some other brands are- 

• AZITHRAL 500, Mfg by- [Alembic pharmaceutical ltd]  
• AZERIKA 500, Mfg by- [ GSK pharmaceuticals ltd]     
•  AZIWOK 500, Mfg by- [wockhardt ltd]                         
• AZILUP 500, Mfg by- [lupin]           

• AZIMAX 250 & AZIMAX 500, Both are Mfg by- [Cipla],  
• AZITRAX, [Amtrax India life science pvt ltd]  
•  AZITROCIN 500, [Alphinity pharmaceuticals]  
•  AZITRON, [Citrus pharma]  
• AZAX 500, mfg by- [Ranbaxy laboratories ltd]  

•  AZOMYCIN 250 & AZOMYCIN 500, both are mfg by-[Cipla]  
• ZITHROMAX 600, mfg by-[Pfizer]  
• ZADY 500, mfg by [Mankind pharmaceuticals ltd]