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Diagram of process of superinfection. 1: Normal microbiota keeps opportunistic pathogens in check. Image shows many different bacteria, only 1 of which is labeled pathogen. 2: Broad-spectrum antibiotics kill nonresistant cells. Image shows all cells but pathogen being killed. 3: Drug-resistant pathogens proliferate and can cause a superinfection. Image shows many of the pathogen.
Broad-spectrum antimicrobial use may lead to the development of a superinfection. (credit: modification of work by Centers for Disease Control and Prevention)
  • What is a superinfection and how does one arise?

Dosage and route of administration

The amount of medication given during a certain time interval is the dosage , and it must be determined carefully to ensure that optimum therapeutic drug levels are achieved at the site of infection without causing significant toxicity ( side effects ) to the patient. Each drug class is associated with a variety of potential side effects, and some of these are described for specific drugs later in this chapter. Despite best efforts to optimize dosing, allergic reactions and other potentially serious side effects do occur. Therefore, the goal is to select the optimum dosage that will minimize the risk of side effects while still achieving clinical cure, and there are important factors to consider when selecting the best dose and dosage interval. For example, in children, dose is based upon the patient’s mass. However, the same is not true for adults and children 12 years of age and older, for which there is typically a single standard dose regardless of the patient’s mass. With the great variability in adult body mass, some experts have argued that mass should be considered for all patients when determining appropriate dosage. M.E. Falagas, D.E. Karageorgopoulos. “Adjustment of Dosing of Antimicrobial Agents for Bodyweight in Adults.” The Lancet 375 no. 9710 (2010):248–251. An additional consideration is how drugs are metabolized and eliminated from the body. In general, patients with a history of liver or kidney dysfunction may experience reduced drug metabolism or clearance from the body, resulting in increased drug levels that may lead to toxicity and make them more prone to side effects.

There are also some factors specific to the drugs themselves that influence appropriate dose and time interval between doses. For example, the half-life , or rate at which 50% of a drug is eliminated from the plasma, can vary significantly between drugs. Some drugs have a short half-life of only 1 hour and must be given multiple times a day, whereas other drugs have half-lives exceeding 12 hours and can be given as a single dose every 24 hours. Although a longer half-life can be considered an advantage for an antibacterial when it comes to convenient dosing intervals, the longer half-life can also be a concern for a drug that has serious side effects because drug levels may remain toxic for a longer time. Last, some drugs are dose dependent, meaning they are more effective when administered in large doses to provide high levels for a short time at the site of infection. Others are time dependent, meaning they are more effective when lower optimum levels are maintained over a longer period of time.

The route of administration , the method used to introduce a drug into the body, is also an important consideration for drug therapy. Drugs that can be administered orally are generally preferred because patients can more conveniently take these drugs at home. However, some drugs are not absorbed easily from the gastrointestinal (GI) tract into the bloodstream. These drugs are often useful for treating diseases of the intestinal tract, such as tapeworms treated with niclosamide , or for decontaminating the bowel, as with colistin . Some drugs that are not absorbed easily, such as bacitracin , polymyxin , and several antifungals, are available as topical preparations for treatment of superficial skin infections. Sometimes, patients may not initially be able to take oral medications because of their illness (e.g., vomiting, intubation for respirator). When this occurs, and when a chosen drug is not absorbed in the GI tract, administration of the drug by a parenteral route (intravenous or intramuscular injection) is preferred and typically is performed in health-care settings. For most drugs, the plasma levels achieved by intravenous administration is substantially higher than levels achieved by oral or intramuscular administration, and this can also be an important consideration when choosing the route of administration for treating an infection ( [link] ).

Questions & Answers

the product obtained by simplest conventional microbial process is
shridhan Reply
the product obtained by simplest conventional microbial fermentation process is
shridhan
curd
Mounika
beer cheese
Khushi
what is macrobiology
Esther Reply
study in microorganisms
Siva
what is lactose
adekanbi Reply
codomint marker such as RELP are useful for
Nandan Reply
how this process start
Radhika Reply
deffination of staining
Bhavanimangali Reply
It's using dies to differentiate microorganism
shalon
Staining can be defined as a process of using stains or dye to differentiate microorganisms in an environment or habitat.
adeolu
with the aid of a well labeled diagram describe the conducting system
Maridad Reply
what is cellular immunity
namugenyi Reply
Cellular Immunity. -Lymphocytes act against target cell. -Acts directly by killing infected cells.
abdinor
What are NK cells
Peter
Natural killer cells
Rahaba
what are Antigen determinant
mary
cellular immunity is the state where the lymphocytes destroy the infected or targeted cell
cynthia
any examples of oedema
cynthia
introduction of microbial diversity-1
Bhavanimangali Reply
List the type of micro organism arround us and how they can be seen and with what kind of instrument
clinton Reply
how is the arrangements of bacteria in bacilli
Vaidah Reply
Provide some examples of bacterial structures that might be used as antibiotic targets and explain why.
Vaidah
Coccobacilli, Club-Shaped bacilli, Bacilli with rounded ends, Fuilform bacilli, Bacilli with ends square.
Enoch
three main antibiotic targets in bacteria: The cell wall or membranes that surrounds the bacterial cell. The machineries that make the nucleic acids DNA and RNA. The machinery that produce proteins
Rushikesh
The bacterial cell wall. Protein production. and DNA synthesis. Why, this is because most drugs (antibiotics) affects the cell wall of the bacteria, which makes the bacteria weak or susceptible in human body.
Enoch
UV rays affecting the..
Mali Reply
what is microbiology
Baba Reply
Microbiology is the study of microorganisms, which are prokaryotic and eukaryotic cell which includes bacteria, fungi, viruses and pathogenic protozoa.
Enoch
Microbiology is the branch of Life science which deals with scientific study of many Microorganisms.
Rushikesh
what is types of microbiology
Alsheikh
Immunology, Bacteriology, Virology, Mycology, Algology etc
Enoch
Virology, Immunology, Bacteriology, Algology, Mycology, Protoozology etc
Enoch
and what is mycology
Alsheikh
Immunology, Serology, Virology, Microbial Genetics, Parasitology, Bacteriology, Mycology, Molecular, Cell Biology, Agricultural, Water,Soil, Food Industrial ,Pharmaceutical, Applied, Environmental, Clinical, Medical,Marine Microbiology, Microbial Systematics, Etc, are & many types of Microbiology.
Rushikesh
study of fungi is called mycology
Munna
Mycology is the branch of Microbiology which deals with scientific study of Fungi.
Rushikesh
Study of microorganisms,which we can't see with our naked eye is called microbiology
Munna
Mycology is the scientific study of Fungi.
Enoch
virology is the study of viruses
Oppah
what is microbiology? microbiology is the study of small microorganisms that we can not with our naked eyes.
Leticia
what is taxonomical classification of microbiology
Bami
The algae, protozoa, slime moulds, fungi, bacteria, archaea and viruses ,are taxonomic classification of Microorganisms
Rushikesh
We have Bacteria, Archaea, Protozoa, Algae, Fungi, Viruses.
Enoch
microbiology is the study of microbes too small to be seen by naked eyes
Maridad
microbiology is a branch of biology which deals with study of smallest living microrganisms such as bacteria protozoa fungi and viruses
Chaitra
microbiology is the study of microorganisms which can't be seen by our naked eyes
Nakaweesi
Micro - Minute Bio - Life Logus - Study
Roshan
what is the meaning of antimicrobial susceptibility testing
Devshree Reply
seven gram positive bacteria
Okocha Reply
seven examples of gram negative bacteria
Okocha
seven examples of gram negative bacteria
Okocha

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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