Sunday, February 5, 2012

ANTI-INFECTIVE AGENTS

ANTI-INFECTIVE AGENTS:

Drugs designed to act selectively on foreign organisms that have invaded and infected the body. 


Range from

  1. Antibiotics 
  2. Antifungal 
  3. Antiprotozoal 
  4. Antihelmintics 
  5. Antiviral 
  6. Antimycobacterial 


General Mechanism of Action: 
  1. Some interfere with the biosynthesis of CELL WALL. 
  2. Some inhibits CHON synthesis 
  3. Some change the cell membrane permeability 
  4. Some inhibit DNA synthesis 
The following videos show the mechanism of actions of certain classes of anti-infective drugs as well as how microorganisms develop resistance against them. 

*After viewing all videos, kindly post your learning and/or reactions by answering the following questions in the comment box. This will serve as a one of your requirements in Pharmacology.


1. What are the pharmacologic implications of the differences in human and microbial cell structures?
2. How does each of the agents fight back infection?
3. What are the possible challenges and limitations that an anti-infective drug can encounter now and in the future?



ANTIBIOTICS & HOW THEY TREAT INFECTION


BETA-LACTAM MECHANISM OF ACTION



MACROLIDE MECHANISM OF ACTION


FLUOROQUINOLONES MECHANISM OF ACTION



VANCOMYCIN MECHANISM OF ACTION


ANTI-FUNGAL AGENTS


THE ACTION OF PHOSOME (LIPOSOMAL AMPHOTERICIN B)


THE ANIMATION OF ANTIMICROBIAL RESISTANCE






9 comments:

  1. 1.) pharmacologic implications of human cell structures,is that about the video i seen a while ago if the baby acquired a bacteria from the mother it multiply and spread through the baby's organ via his blood.In the microbial structures is that some other gram negative bacteria do not posses periplasmic space,but only have periplasm. penicillin binding protien, gram positive bacteria have more layered than gram negative bacteria,that is why have a thicker cell wall.
    2.) one is antibiotic agents act to destroy or supress the growth of microorganism. An antitubecular agents kill or inhibit the growth of mycobacterium organism.It is used to treat tuberculosis caused by mycobacterium tuberculosis,a necrotizing infection most commonly affecting the lungs.The antifungal agent most drugs bind to components of the fungal cell membrane leading to death of the fungal cell.this is used to treat infection caused by fungi whether systemic or local.An anti viral agents are used to treat infections that occurs from viruses.This is not effective as antibacterial because the viruses are not totally destroyed and continue to live with in the host cells.On the video the macrolides normally drugs are bacteriostatic in action but in a higher doses can be bactericidal;they inhibit the growth of microorganism without causing a complete kill.Inhibits the protien synthesis by binding to the 50s subunit of the bacterial ribosome.On Beta -lactim good coverage of most gram negative organisms,including those organism resistant to penicillin.On fluoroquinolones a broad spectrum synthetic antibiotic class with both gram positive and gram negative bacteria coverage.This drugs interference with DNA replication,it is a bactericidal drugs.
    3.) possible challenges and limitations that an anti-ineffective drug can encounter now and in the future are: antibacterial,antifungal,antitubercular,antiviral,antiprotozoal and antihelmintics.

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  2. 1. compounds with selective toxicity can be used clinically - they must be highly effective against a microorganism but have minimal toxicity to humans. In practice, this is expressed in terms of the therapeutic index - the ratio of the toxic dose to the therapeutic dose. The larger the index, the better is its therapeutic value.
    2. Antibiotic- Interference with cell wall synthesis.Interference with protein synthesis.Interference with DNA replication.Acting as a metabolite to disrupt critical metabolic reactions inside the bacterial cell.Bactericidal: kill bacteria. Bacteriostatic: inhibit growth of susceptible bacteria, rather than killing them immediately; will eventually lead to bacterial death
    Antivirals- Able to enter the cells infected with virus. Interfere with viral nucleic acid synthesis and/or regulation. Some agents interfere with ability of virus to bind to cells. Some agents stimulate the body’s immune system
    Antituberculous Agents- Protein wall synthesis inhibitors (streptomycin, kanamycin,capreomycin, rifampin, rifabutin). Cell wall synthesis inhibitors (cycloserine, ethionamide, isoniazid)
    Antifungal Agents
    Antimalarial Agents- Attack the parasite during the asexual phase, when it is vulnerable. Erythrocytic phase drugs: chloroquine, hydroxychloroquine, quinine,mefloquine. Primaquine: kills parasite in both phases. May be used together for synergistic or additive killing power
    Antiprotozoals- Disruption of DNA synthesis as well as nucleic acid synthesis. Bactericidal, amoebicidal, trichomonacidal. Used for treatment of trichomoniasis, amoebiasis, giardiasis, anaerobic infections, and antibiotic-associated pseudomembranous colitis
    Anthelmintics
    3. Anti-infective drugs can develop drug resistance. Today, especially in hospitals, there are strains of staph bacteria that are resistant to, not just one, but nearly all known antibiotics. More than two-dozen types of bacteria are now resistant to one or more types of antibiotics that had previously been effective against them.

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    Replies
    1. your answers should be based on the videos you have viewed.

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  3. an anti infective agents prevents infectious agents or kill infectious agents which prevents the spread of infections. each anti infected agents has the capability to cure disease with respect to its drug resistance and target pathogens. an antibiotics cure disease by killing or injuring bacteria.although antibiotics are useful in a wide variety of infection antibiotics treat bacterial infections.antiprotozoal treat disease caused by protozoa.antihelmintics drugs used to treat infection with parasitic worms.antiviral treat viral infections but do not destroy their target pathogen but they inhibit their development.antimycobacterial drug treat disease caused by members of mycobacterium genus.the different drugs are usefull because of their effectiveness in treating diseases and or minimizing pathogens.their different forms of curative aspects is reliable and the very reason why this anti infective agents exist.
    1.the rate of bleeding complications on humans and the structural damage against microbial cells upon the inhibitions of anti infective agents.
    2.increases their effective use overall empowering the work of killing pathogens inhibitors.
    3.this anti infective agents continously will work on killing pathogents contributing curability and its essential may remain usefull even now or in the future.

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    1. What have you learned in the videos presented?

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  4. This comment has been removed by the author.

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  5. 1.) A human cells has its own antibodies to fight back infection which is known as white blood cells. The time infection a rises white blood cells increases in number. In the videos above shows that baby immunity is not enough to kill microorganism so he needs the help of antibiotics. This antibiotic will kill the microbial cells structure that is responsible for the infection
    2.)a.)The beta-lactam antibiotics can kill susceptible bacteria. The cell walls of bacteria are essential for their normal growth and development.Beta-lactamases are enzymes produced by some bacteria and are responsible for their resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems (ertapenem) (Cephalosporins are relatively resistant to beta-lactamase). These antibiotics have a common element in their molecular structure: a four-atom ring known as a beta-lactam. The lactamase enzyme breaks that ring open, deactivating the molecule's antibacterial properties.

    b.) The fluoroquinolones are a family of synthetic broad-spectrum antibiotics, which eradicate bacteria by interfering with DNA replication. However, the fluoroquinolones are relatively ineffective against intracellular pathogens.

    c.) Anti-infectives are drugs that can either kill an infectious agent or inhibit it from spreading. Anti-infectives include antibiotics and antibacterials, antifungals, antivirals and antiproatozoans.

    d.) Macrolides are a class of antibiotics known as broad-spectrum antibiotics that are used to treat a wide range of bacterial infections. Macrolides are derived from Streptomyces species. They have a common macrolytic lactone ring to which one or more sugars are attached. They are different from one another in their chemical substitutions on structures of various carbon atoms and the amino and neutral sugars.e.) Vancomycin is an antibiotic. It is used to fight susceptible bacteria in the body that cause serious infections.Vancomycin is used to treat infections of the intestines that cause colitis (inflammation of the large intestine).
    3.) The possible challenges and limitations that an anti-infective drug can encounter now and in the future is that prolong used of it may result to resistance to microorganism and worse of it will develop superinfecrtion.

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    Replies
    1. Reena, I commend your output... You understood and answered the 2 questions correctly. This blog was created for you to easily learn and understand difficult concepts. and based on your answers, it makes all effort worthwhile. Keep up the good work!

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  6. Maam I posted my answer last night at around 10pm but when i open this blog today i cant found my answer that's why i posted again..please do consider this because i don't know what happened..thnx

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