Quiz 2 Study Guide
Antibiotics
Review terminology:
1. Selective Toxicity: The ability of a drug to injure a target cell or target organism without
injuring other cells or organisms that are in intimate contact with the target. Refers to the
ability of an antibiotic to injure only invading microbes and avoiding injuring the host.
2. Culture and Sensitivity test: Is a test done when trying to treat for infection. Culture is
to determine the bacteria or fungus causing the infection . Sensitivity checks for what
kind of medicine will work best against the bacteria or fungus. Test used to test drug
sensitivity is the disk diffusion test, also known as the kirby-bauer test.
3. Mechanisms of Resistance : decreases concentration of a drug at its site of action; alters
the structure of a drug target molecules; produces a drug antagonist; causes drug
inactivation. Broad spectrum antibiotics promote the emergence of drug resistance.
4. CYP3A4: inhibitor is Drugs used for erectile dysfunction ; it suppresses the metabolism
of sildenafil (viagra), thereby increasing its level. Combination should be used with
caution.
● Intraconazole (antifungal) inhibits CYP3A4
5. CYP450: Cytochrome P450 Enzyme 17 inhibitor
Abiraterone ( Zytiga) indicated for combined use with prednisone to treat metastatic
castration-resistant prostate cancer, if castration has not occured it can inhibit androgen
production by the testes.
Ketoconazole ( Nizoral) used for fungal infections, can be used off label for prostate
● Azoles( antifungal ) has the ability to inhibit CYP450
, 6. Disulfiram-like effect: Is an unpleasant effect caused by the medication when ingesting
alcohol. Manifest as nause, copious vomiting, flushing , palpitations, headache, sweating
, thirst, chest pain, weakness, blurred vision and hypotension.
7. Superinfection: A new infection that appears during a course of treatment for a primary
infection. When the body's normal flora is decreased the overgrowth of fungi and yeast
can occur, an example is yeast infections after the use of antibiotics. They occur most
often with broad spectrum antibiotics
8. Cross-sensitivity: is defined as sensitivity to one substance that renders an individual
sensitive to other substances of similar chemical structure. B- lactams and sulfonamides
are the most common.
9. Cross-resistance: Resistance to all antibiotics belonging to the same class due to a single
mechanism. The more active the drug the lower the level of resistance
Review labs:
WBC- Purpose of white blood cells can detect hidden infections within your body.
- Neutrophil- type of WBC, lead the immune system’s response. Neutrophils are
55-70 % of the wbc. !st cell to arrive on the scene of the infection. NORM COUNT-
2500-7500. Increase with infection, may decrease due to leukemia, vit b12 deficiency
cnd chemo. The chemokines attract the neutrophils. It addresses foreign invaders by
“eating them” also known as phagocytosis. Lives for 8 hours only.
-
Lymphocytes- small WBC that actually play an outsized role in defending your body
from disease. Role is to fight infections by producing antibodies. Also kill cells in our
body that are infected. Moves through the lymphatic system. Uses phagocytosis as well.
2 types- T cells and B cells.
,T CELLS- continuously scan and monitor your cells for infection and the risk of
infection. T stands for thymus (small glands in chest where T cells mature). T cells spot
infected cells and proceed to kill the cell. It also remembers the infectious agent so it can
attack it quicker if the infection is repeated. Also kills cancer cells.
B-CELLS- don’t attack and kill cells, virus or bacteria. It manufactures antibodies that
actually stick to the surface of invaders , disabling those invader and spotlighting them
for clean up. Also made in the bone marrow.
-
Basophil- most common for parasites. Involved in producing some of the symptoms
caused by allergic reactions (watery eyes, sneezing, runny nose. Made in the bone
marrow and developed and differentiated by hematopoiesis. Makes up 0.5% of WBC.
Lives for a few days. Are granulocytes- contains small granules inside the, granules
store and release enzymes and chemicals, specifically histamine. Does not remember
organism, they simply recognize invaders that do not belong and should be destroyed.
Triggers production of immunoglobulin E (IgE).
-
Eosinophil- important against parasitic infections. Phagocytic but less efficient than
neutrophils in killing intracellular bacteria. May modulate immediate hypersensitivity
reactions by degrading or inactivating mediators released by mast cells, such as
histamine, leukotrienes (which may cause vasoconstriction and bronchoconstriction).
And lysophospholipids and heparin. Regulated by T cells through secretion of the
hematopoietic growth factors granulocyte-macrophage colony-stimulating factor. ,
interleukin-3 and 5. Il-5 increases eosinophil production.
, Review drugs (mechanism of action, indication, adverse effects, and which patients to avoid):
● Penicillins : B Lactam
○ Action: Active against a variety of bacteria. Inhibits bacterial cell walls; weakens
the cell walls causing the bacteria to take excessive amounts of water and rupture.
Inhibition of transpeptidases and activation of autolysins.
○ Indication: used to treat infections caused by sensitive bacteria; bacteria that are
undergoing cell growth and division, active against gram + bacteria(narrow
spectrum) Gram + & Gram - (broad spectrum).
○ Adverse effects: allergic reactions ( rash, hives, anaphylaxis, Penicillin is
considered one of the least toxic and among the safest.
○ Avoid: pt with hx of severe allergic reactions to penicillins, cephalosporins and
carbapenems.
● Cephalosporins (differences between generations) :
○ Actions: are B-lactams antibiotics. Bactericidal drugs action similar to
penicillins. Bind to PBP (penicillin-binding proteins) causing cell death by lysis.
Effective on cells undergoing cell growth and division.
○ Uses:
■ 1st gen. (cefazolin, Keflex) used against Gram + bacteria (surgical
prophylaxis) ;
■ 2nd Gen.(ceflacor, cefotetan, ceftin) used for Gram + and - ( otitis,
sinusitis, resp. infections);
■ 3rd/ 4th Gen ( cefximine, cefdinir, cefotaximine) used for Gram - (
meningitis, complicated intra abdominal and UTI, HA pneumonia);
■ 5th Gen (ceftaroline) used for Gram + (MRSA).
○ Adverse Effect: allergic reactions (rash, urticaria, hypotension, difficulty
breathing) bronchospasms and anaphylaxis are rare. Avoid: hx of allergy to
cephalosporins or severe allergy to penicillins
● Tetracycline: Broad spectrum antibiotics- Bacteriostatic inhibitor
➔ Action: suppress bacterial growth by inhibition of protein synthesis. Bind to the 30s
ribosomal subunit, inhibits transfer of RNA to the messenger RNA- ribosome complex.
Enter bacteria by way of an energy dependent transport system.
➔ Uses: Treatment of infectious disease; Acne, peptic ulcer disease; Periodontal disease.
Antibiotics
Review terminology:
1. Selective Toxicity: The ability of a drug to injure a target cell or target organism without
injuring other cells or organisms that are in intimate contact with the target. Refers to the
ability of an antibiotic to injure only invading microbes and avoiding injuring the host.
2. Culture and Sensitivity test: Is a test done when trying to treat for infection. Culture is
to determine the bacteria or fungus causing the infection . Sensitivity checks for what
kind of medicine will work best against the bacteria or fungus. Test used to test drug
sensitivity is the disk diffusion test, also known as the kirby-bauer test.
3. Mechanisms of Resistance : decreases concentration of a drug at its site of action; alters
the structure of a drug target molecules; produces a drug antagonist; causes drug
inactivation. Broad spectrum antibiotics promote the emergence of drug resistance.
4. CYP3A4: inhibitor is Drugs used for erectile dysfunction ; it suppresses the metabolism
of sildenafil (viagra), thereby increasing its level. Combination should be used with
caution.
● Intraconazole (antifungal) inhibits CYP3A4
5. CYP450: Cytochrome P450 Enzyme 17 inhibitor
Abiraterone ( Zytiga) indicated for combined use with prednisone to treat metastatic
castration-resistant prostate cancer, if castration has not occured it can inhibit androgen
production by the testes.
Ketoconazole ( Nizoral) used for fungal infections, can be used off label for prostate
● Azoles( antifungal ) has the ability to inhibit CYP450
, 6. Disulfiram-like effect: Is an unpleasant effect caused by the medication when ingesting
alcohol. Manifest as nause, copious vomiting, flushing , palpitations, headache, sweating
, thirst, chest pain, weakness, blurred vision and hypotension.
7. Superinfection: A new infection that appears during a course of treatment for a primary
infection. When the body's normal flora is decreased the overgrowth of fungi and yeast
can occur, an example is yeast infections after the use of antibiotics. They occur most
often with broad spectrum antibiotics
8. Cross-sensitivity: is defined as sensitivity to one substance that renders an individual
sensitive to other substances of similar chemical structure. B- lactams and sulfonamides
are the most common.
9. Cross-resistance: Resistance to all antibiotics belonging to the same class due to a single
mechanism. The more active the drug the lower the level of resistance
Review labs:
WBC- Purpose of white blood cells can detect hidden infections within your body.
- Neutrophil- type of WBC, lead the immune system’s response. Neutrophils are
55-70 % of the wbc. !st cell to arrive on the scene of the infection. NORM COUNT-
2500-7500. Increase with infection, may decrease due to leukemia, vit b12 deficiency
cnd chemo. The chemokines attract the neutrophils. It addresses foreign invaders by
“eating them” also known as phagocytosis. Lives for 8 hours only.
-
Lymphocytes- small WBC that actually play an outsized role in defending your body
from disease. Role is to fight infections by producing antibodies. Also kill cells in our
body that are infected. Moves through the lymphatic system. Uses phagocytosis as well.
2 types- T cells and B cells.
,T CELLS- continuously scan and monitor your cells for infection and the risk of
infection. T stands for thymus (small glands in chest where T cells mature). T cells spot
infected cells and proceed to kill the cell. It also remembers the infectious agent so it can
attack it quicker if the infection is repeated. Also kills cancer cells.
B-CELLS- don’t attack and kill cells, virus or bacteria. It manufactures antibodies that
actually stick to the surface of invaders , disabling those invader and spotlighting them
for clean up. Also made in the bone marrow.
-
Basophil- most common for parasites. Involved in producing some of the symptoms
caused by allergic reactions (watery eyes, sneezing, runny nose. Made in the bone
marrow and developed and differentiated by hematopoiesis. Makes up 0.5% of WBC.
Lives for a few days. Are granulocytes- contains small granules inside the, granules
store and release enzymes and chemicals, specifically histamine. Does not remember
organism, they simply recognize invaders that do not belong and should be destroyed.
Triggers production of immunoglobulin E (IgE).
-
Eosinophil- important against parasitic infections. Phagocytic but less efficient than
neutrophils in killing intracellular bacteria. May modulate immediate hypersensitivity
reactions by degrading or inactivating mediators released by mast cells, such as
histamine, leukotrienes (which may cause vasoconstriction and bronchoconstriction).
And lysophospholipids and heparin. Regulated by T cells through secretion of the
hematopoietic growth factors granulocyte-macrophage colony-stimulating factor. ,
interleukin-3 and 5. Il-5 increases eosinophil production.
, Review drugs (mechanism of action, indication, adverse effects, and which patients to avoid):
● Penicillins : B Lactam
○ Action: Active against a variety of bacteria. Inhibits bacterial cell walls; weakens
the cell walls causing the bacteria to take excessive amounts of water and rupture.
Inhibition of transpeptidases and activation of autolysins.
○ Indication: used to treat infections caused by sensitive bacteria; bacteria that are
undergoing cell growth and division, active against gram + bacteria(narrow
spectrum) Gram + & Gram - (broad spectrum).
○ Adverse effects: allergic reactions ( rash, hives, anaphylaxis, Penicillin is
considered one of the least toxic and among the safest.
○ Avoid: pt with hx of severe allergic reactions to penicillins, cephalosporins and
carbapenems.
● Cephalosporins (differences between generations) :
○ Actions: are B-lactams antibiotics. Bactericidal drugs action similar to
penicillins. Bind to PBP (penicillin-binding proteins) causing cell death by lysis.
Effective on cells undergoing cell growth and division.
○ Uses:
■ 1st gen. (cefazolin, Keflex) used against Gram + bacteria (surgical
prophylaxis) ;
■ 2nd Gen.(ceflacor, cefotetan, ceftin) used for Gram + and - ( otitis,
sinusitis, resp. infections);
■ 3rd/ 4th Gen ( cefximine, cefdinir, cefotaximine) used for Gram - (
meningitis, complicated intra abdominal and UTI, HA pneumonia);
■ 5th Gen (ceftaroline) used for Gram + (MRSA).
○ Adverse Effect: allergic reactions (rash, urticaria, hypotension, difficulty
breathing) bronchospasms and anaphylaxis are rare. Avoid: hx of allergy to
cephalosporins or severe allergy to penicillins
● Tetracycline: Broad spectrum antibiotics- Bacteriostatic inhibitor
➔ Action: suppress bacterial growth by inhibition of protein synthesis. Bind to the 30s
ribosomal subunit, inhibits transfer of RNA to the messenger RNA- ribosome complex.
Enter bacteria by way of an energy dependent transport system.
➔ Uses: Treatment of infectious disease; Acne, peptic ulcer disease; Periodontal disease.
