Antimicrobial Treatment Flashcards
What are the origins of antimicrobial drugs?
Some microbes naturally produce antibiotics for antagonistic interactions, and other chemists modify or imitate these natural drugs.
What is prophylaxis?
Drug use to prevent imminent infection of a person at risk.
What is antimicrobial chemotherapy
The use of chemotherapeutic drugs to control infection.
What is antimicrobials?
An all-inclusive term for any antimicrobial drug regardless of what type of microorganisms it targets.
What are antibiotics?
Substances produced by the natural metabolic processes of some microorganisms or science created that can inhibit or destroy microorganisms.
What are semi-synthetic drugs?
Drugs that are chemically modified in a lab after being isolated from natural sources
What are synthetic drugs?
Drugs that are produced entirely by chemical reactions within a lab setting.
Narrow-spectrum (limited)
Antimicrobials are effective against a limited array of microbial types.
What is an example of a narrow spectrum?
Polymyxin or Isoniazid
What is broad spectrum (extended)
antimicrobials effective against a wide variety of microbial types
What is an example of a broad spectrum?
Tetracyclines or Carbapenems
What is the first factor to start antimicrobial therapy?
Identify the microorganism causing the infection asking the question “How can we determine this?”
What is the second factor to start antimicrobial therapy?
The degree of the microorganism’s sensitivity to various drugs by asking “What tests are usually used?”
What is the last and third factor to start antimicrobial therapy?
The overall medical condition of the patient by asking “Why is this a critical factor?”
Identification of the infectious agent from the body specimens should be attempted as soon as possible by __________
a direct examination of body fluids, sputum or stool, rapid initial method for detecting and perhaps identifying bacteria or fungi
How do we test for drug susceptibility (sensitivity)
Kirby-Bauer technique
What is the Kirby-Bauer technique?
A test showing antimicrobial susceptibility using large agar plates, bacterial lawn, and antibiotic-infused discs.
What is the etest alternative for the Kirby-Bauer procedure?
A MIC (minimum inhibitory concentration) all by providing additional information on a drug’s effectiveness
Because drug toxicity is of concern, it is best to choose the one with __________
high selective toxicity for the infectious agent and low human toxicity.
What is a therapeutic index (TI)?
The ratio dosage of the drug that is toxic to humans to its minimum effective (therapeutic) dose
Why is patient history considered?
Its presents pre-existing medical conditions that will influence the activity of the drug or the responses of the patient, a history of allergy to certain drugs, and some human populations might require special precations.
If MIC and Therapeutic Index fail, the failure is usually due to:
The inability of the drug to diffuse onto the body compartment, resistant microbes, and infections caused by more than one pathogen which are some resistant to the drug.
An antibiotic with a therapeutic index of 4 is less toxic than one with a therapeutic index of 40.
TBA
Once antimicrobial susceptibility is established, choosing the right antibiotic is an easy process.
False
What is drug resistance?
Adaptive response in which microorganisms begin to tolerate an amount of drug that would ordinarily be inhibitory due to the genetic versatility and adaptability of microbial populations
What is intrinsic resistance?
A genetic gene of microbe, bacteria must be resistant to any antibiotic that they themselves produce
What is acquired resistance?
A developed bacteria resistance to a drug to which they were previously sensitive
What is selective toxicity?
Antimicrobial drugs should kill or inhibit microbial cells without simultaneously damaging the host cells.
Drugs that act upon a structure common to both the infective agent and the host cell
become more similar to that of the host selective toxicity becomes more difficult.
Specific drugs that target the cell wall are
Penicillins - suffix cillin, Cephalosporins - beginning in ceph & Carbapenems - suffix in nem
Miscellaneous drugs targeting the cell wall
Bacitracin, Isoniazid, Vancomycin, Fosfomycin, & Tromethamine
What are the primary sites of action of antimicrobial drugs on bacterial cells?
Cell Wall, Protein Synthesis, Folic Acid Synthesis, DNA or RNA and Cell membrane
Antimicrobial drugs targeting protein synthesis?
Aminoglycoside, tetracyclines, glycyclines, & marcolides.
What are some miscellaneous drugs for the target protein synthesis
CLS (clindamycin, linezolid, and synercid.
In protein synthesis what are some broad spectrum durgs?
Aminoglycoside, tetracyclines, & macrolides.
Antimicrobial drugs for folic acid synthesis?
Sulfonamides or any sulfa drugs which are synthetic drugs.
Sulfamethaoxazole treats?
Acute urinary tractions infections
Silver sulfadiazine treats?
Burns and eye infection
Trimethoprim
A combination drug effect of sulfa-oxazole and synergistic
Antimicrobial drugs targeting DNA or RNA
Fluoroquinolones as broad spectrum with side effects of seizures and brain distrubances and anything ending in -acin
Anitimicrobial drugs targeting cell membranes
Polymyxin (narrow spectrum), E & B, and Daptomycin, they are toxic to the kidneys
All penicillin drugs consist of 3 parts :
thiazolidine ring, a beta-lactam, and a variable side chain.
Aminoglycoside drugs
Composed of one or more amino sugars and an aminocyclitol a 6 carbon ring
Different phenotypes are expressed by biofilm bacteria
True
Treatment of biofilms are partial successful strategies
Interrupting quorum sensing pathways and adding DNase to antibiotics
Similarites between human cells means that drugs toxic to fungi are also capable of harming tissues.
True
Agent drug used to treat fungal infections
Marcolide polyenes, Azoles, Echinocandines and Allylamines
Macrolide Polyenes
Amphotericin B can be used to treat skin, mucous membrane lesions and the injectable form can treat histoplasmosis.
Azoles
Anything with suffix zoles, used to treat infections in the skin, mouth, and vagina
Echinocandins
Anything with suffix fungin, they inhibit fungal cell wall synthesis
Allylamines
Terbinafine and Naftifine, used to treat ringworm and other cutaneous mycoses.
Antimalarial drugs : Quinine
A principal treatment for 100 of years & replaced with chloroquine and primaquine with less toxicity
Chemotherapy for protozoan infections
Metronidazole and Ameobicide
Antihelminthic drug therapy
Mebendazole and Albendazole, they inhibit the function of microtubule in worms, eggs and larvae
Pyrantel
An antihelminthic drug therapy that paralyzes the muscles of intestinal roundworms
Praziquantel and Ivermectin
Antihelminthic drug therapy
Nearly 80% of all antibiotics in the US are given to
livestock
Overgrowth of certain microbes due to antibiotic therapy is known as
superinfection
_______ Have been used in eastern europe to effectively treat bacterial infections
Bacteriophages
An antibiotic that acts on the bacterial cell wall will have no effect on human cell
True
An antioboitic that acts on the bacterial ribosome will have no effect on a human cell
False
