Antibiotics Flashcards by Lamar Castleberry

What are the 3 General Mechanisms of Bacterial Destruction?

Cell Wall Disruption
Enzymatic Inhibition
Protein Synthesis Disruption

How well did you know this?

Not at all

Perfectly

Name the general Beta Lactam Antibiotics (PCCM) and the mechanism of action

Penicillin
Cephalosporin
Carbapenems
Monobactams
MOA: Bactericidal effects by interfering with ability to form the cell wall; cell swell and burst

How well did you know this?

Not at all

Perfectly

What is Beta Lactamase and name the three Beta Lactamase Inhibitors (-bactam +CA)

Beta Lactamase is produced by bacteria to inactivate antibiotics
Sulbactam
Clavulanate (Clavonic Acid)
Tazobactam

How well did you know this?

Not at all

Perfectly

What is penicillinase and name the 4 Penicillinase Resistant Penicillins (think oxa +Naf)

Some bacteria produce penicillinase that destroys beta lactam ring - making penicillin ineffective
Dicloxacillin
Cloxacillin
Oxacillin
Naficillin

How well did you know this?

Not at all

Perfectly

Do not mix penicillin with ____ in same IV solution

b/c it inactivates _____.

Aminoglycosides for both answers (usually added to regime to increase killing of pseuonomas)

How well did you know this?

Not at all

Perfectly

What are the penicillin A/E

GI: N/V & Diarrhea & Abd Cramp
Glossitis -inflammed tongue, Somatitis - swelling/sores in mouth, Furry Tongue
Hypersensitivity Rxn: Rash
Pruritus (itching)
Fever
Anaphylaxis (5-10% of ppl- within 2-30min ):
Laryngeal Edema
Bronchoconstriction
Hypotension
Pain/Itching @ injection site

How well did you know this?

Not at all

Perfectly

Name the three alternatives to use and the two not to use if penicillin anaphylactic reaction is intact?
Which one can be used if there is simply a mild allergy to PCN?

Use: Vancomycin, Clindamycin, Macrolides
Avoid: Cephalosporin or Carbapenems (cephalosporin can be used as alternative if mild allergy to PCN)

How well did you know this?

Not at all

Perfectly

What is the name of the broad spectrum Penicillin that can cross BBB?

Ampicillin

Amoxicillin is the only other broad spectrum in class - both inactivated by beta lactamase

How well did you know this?

Not at all

Perfectly

What are the beverages to avoid when taking penicillin - can decrease effectiveness

Caffine-containing beverages
Fruit Juices
Tomato Juice
(and citrus fruits)

How well did you know this?

Not at all

Perfectly

How many generations of cephalosporins are there?

5 (all cephalosporins commonly start with cef or cep)

How well did you know this?

Not at all

Perfectly

1st and 2nd generation cephalosporin commonly used against ______ and limited against ____.

Used: Gram Positive
Limited: Gram Negative

How well did you know this?

Not at all

Perfectly

Name the two common 1st Generation Cephalosporin Drugs (think ceph)

Cephalexin & Cephazolin

How well did you know this?

Not at all

Perfectly

Name the two common 2nd Generation Cephalosporin Drugs (think cef)

Cefoxitin

Cefuroxime

How well did you know this?

Not at all

Perfectly

Name the two common third generation cephalosporin drugs (think ceft)

Ceftazidime

Ceftriaxone

How well did you know this?

Not at all

Perfectly

Which generation is the only cephalosporin approved to treat MRSA - Name the drug

5th Generation (Ceftaroline)

How well did you know this?

Not at all

Perfectly

Which generation of cephalosporin is used against gram negative microbes?

Third Generation

How well did you know this?

Not at all

Perfectly

Ceftazidime is active against pseudomonas. What drug class is often given to enhance it’s killing effects?

Aminoglycosides

How well did you know this?

Not at all

Perfectly

Which generation of cephalosporin is most effective against meningitis?

Third Generation

How well did you know this?

Not at all

Perfectly

Which two cephalosporin generations are possibly responsible for C.Diff spread?

Third and Fourth

How well did you know this?

Not at all

Perfectly

What are the cephalosporin A/E

(Common to penecillin)

Diarrhea, Abd cramps, Rash, pruritis, redness, edema

How well did you know this?

Not at all

Perfectly

What happens when cephalosporin interacts with antacid, iron, probenecid, or oral contraceptives?

Antacids & Iron - Dec. effectiveness of drug
Probenecid - Dec. renal excretion
Oral Cont. - Enhances OCP metabolism; inc. risk of pregnancy

How well did you know this?

Not at all

Perfectly

When given ceftriaxone and calcium together, what happens? (in neonates)
Necessary precautions to take?

Form fatal precipitates (solids that fall out into sol’n) in lungs and kidney
Dont give through same line OR differeent lines unles 48 hours in between them - In all other patients, may be given sequentially through same line (must flush between solutions)

How well did you know this?

Not at all

Perfectly

What is the cephalosporin drug that can not be given with calcium?

Ceftriaxone

How well did you know this?

Not at all

Perfectly

Which antimicrobial drug class has the broadest action of all antibiotics up to date?

Carbapenems

How well did you know this?

Not at all

Perfectly

What are the drugs in carbapenem class?(give suffix)

-penem

Carbapenems must be infused for how long?

over 60 minutes

All carbapenems interacts with ____ to reduce blood levels of that drug. (what is drug used for) What is the effect?

Valproate - used to control seizures | May cause seizures (also lowers seizure threshold)

What are the carbapenems A/E?

Similiar to penicillin | - mild diarrhea, abd cramps, rash, pruritis, redness, edema

Imipenem is rapidly inactivated by _______ (enzyme in kidney) Which drug is combined to inhibit that enzyme?

Dipeptidase; 70% of imipenem is excreted unchanged in urine - 1/2 life of about 1 hour because of this enzyme Cilastatin inc. half life and tissue penetration

Only monobactam drug in class?

Azactam

All A/E and MOA in these classes of antibiotics are very similar, almost identical - Name them

Penicillin Carbapenems Cephalosporins Monobactam

What is the name of aminoglycosides? (suffix) What is their MOA? Concentration or time dependent?

-mycin | rapid bactericidal action through disruption of protein synthesis (30S Ribosome) - Concentration dependent

Aminoglycosides are used to treat aerobic or anaerobic bacteria / gram negative or gram positive? bacteria?

Aerobic gram negative bacteria ("glycosides" require O2 for transport across bacteria cell membrane- anaerobic environment doesn't allow transport) Inactive against most gram positive bacteria

Which aminoglycoside is least susceptible to inactivation by bacterial enzymes?

Amikacin

Two major adverse effects of aminoglycosides (NO!)

Ototoxicity - impairment of hearing and balance; can be irreversible; R/T excessive trough levels (NOT Peak) Nephrotoxicity - generally reversible; binds tightly to renal tissue achieving 50x dose of that in serum levels -> Acute Tubular Necrosis

Other A/E of aminglycosides?

Hypersensitivity rxn: rash, pruritis (itching), urticaria (hives) Blood Dyscrasias Neuromuscular blockade --> causes paralysis of affected skeletal muscle

What is the name of macrolides? (suffix) | What is their MOA?

-thromycin | inhibition of protein synthesis (50s ribosome)

Do not administer metal ions 2 hours before or after taking this drug in macrolide class?

Azithromycin (Some antacids contain metal ions)

``` What is function of cytochrome p450? Which drug in macrolide class is the only one that does not affect this enzyme? All others do what to it? ```

Metabolize toxic compounds (drugs) Azithromycin All others inhibit p450 - inc. toxicity of drug in body

Macrolides A/E (specifically erythromycin)?

GI: Hepatotoxic, Heartburn, Flatulence, N/V & Diarrhea CV: Prolonged QT interval Thrombophlebitis, hearing loss, and (pyloric stenosis in infants)

Can macrolides (specifically erythromycin) cross placenta and CSF?

Placenta - yes | CSF - no

Azithromycin A/E?

Sun sensitivity and diarrhea

Which two macrolides have similar A/E?

Erythromycin & Clarithromycin

Tetracylines has ability to bind with metallic ions and form insoluble compounds. Therefore avoid taking ____ when on this medication

Antacids

What is name of tetracyclines? (suffix) | What is MOA?

-cyclines | Inhibit bacterial protein synthesis (30s ribosome)

3 antibiotic classes contraindicated in pregnancy?

``` Tetracycline Sulfonamides Quinolones Flagyl Chloramphenicol ```

Which drug in tetracycline class to give in pt with SIADH (syndrome of inappropriate anti-diuretic hormone)?

Demeclocycline - inhibits ADH

Can tetracyclines penetrate BBB & CSF?

Yes - specifically minocycline and doxycycline

All other tetracyclines have reduced absorption when taken with food except?

Minocycline

Avoid these items when on tetracyclines

Iron, calcium products, Magnesium & aluminum (laxatives/Antacids), Zinc Can decrease efffectiveness of OCP

Unique A/E of tetracyclines?

``` Teeth discoloration Photosensitivity Rxn Yeast Infection Exacerbation of Lupus Buldging Fontanelles Thrombocytopenia/anemia ```

What are names of the quinolones? (suffix) | MOA?

-floxacin | destroy bacteria by altering bacteria DNA

Unique A/E of quinolones?

Black Box Warning: ruptured tendons & tendonitis CNS: Altered mental status, convulsions, depression, dizziness GI: N/V Flautulence, Heartburn, Diarrhea, oral candidiasis CV: prolonged QT interval Skin: Rash, Pruritis, Flushing, Urticaria - Photosensitive

Quinolone interaction with dairy products, antacids and other metallic ions, and probenecid?

Dairy, Antacids, and metallic ions - Reduce asorption | Probenecid - Reduce excretion

What is probenecid?

Renal Tubular Transport Blocking Agent

Name of sulfonamides? (pre-fix) | MOA?

Sulfa | Prevents bacteria synthesis of folic acid --inhibiting growth (bacteriostatic)

If patient has known sulfa allergy, do not give drugs of this class

COX 2 Inhibitors

Sulfa drug-drug interactions with warfarin and phenytoin

Warfarin - inc. risk of bleeding | Phenytoin - Inc. toxicity

Unique Sulfa A/E

``` Steven Johnson Syndrome Kernicterus (Neurotoxic) - bilirubin deposition in brain of newborns Convulsion Anemia/Thrombocytopenia Photosensitivity Rxn Delayed skin Rash & pancreatitis ```

Which class of antibiotics to avoid if pt has G6PD deficiency?

Sulfonamides

Oral anticoagulants (warfarin) taken with ______ can prolong INR leading to bleeding

Quinolone

DOC for MRSA and severe C.Diff?

Vancomycin

A/E of Vancomycin?

Red Man Syndrome - flushing/itching of head and neck, hypotension; all from rapid IV infusion Ototoxicity (may be permanent or reversible) Nephrotoxicity

MOA of Vancomycin

Destroys bacterial cell wall

How long should vancomycin be infused if given IV?

over 60 minutes

Clindamycin MOA?

inhibits protein synthesis - normally bacteriostatic but @ high doses it is bactericidal

Unique A/E of clindamycin?

Steven Johnson - first appears as flu like symptomes then develops into painful rashes, blisters, and eye redness EKG Changes - caused by rapid IV infusion C.Diff!!

What is C.Diff? | Which antibiotic can cause C.Diff?

normally harmless microflora in GI; external stimulus upsets gut causing abnormal overgrowth and release of toxins attacking the lining of intestines (Pseudomembranous colitis) Clindamycin

Which drug is used against multi-drug resistant gram positive pathogens? (eg Vancomycin resistent enterococci and Methicillin resistant staphylococcus aureus)

Linezolid

Which drug is used as prophylaxis in abdominal surgery, vaginal surgery, and colorectal surgery?

Metronidiazole (Flagyl) - also used in protozoal infections and for C diff

Which drug can cause fatal aplastic anemia and grey baby syndrome(vomiting, abd distension, cyanosis, grey skin discoloration)? Why use this drug?

Chloramphenicol | Used only for life-threatening infections for which safer meds are ineffective

Name three antibiotic classes that have adverse photosensitivity effect

Sulfonamides, tetracyclines, quinolones

Which antibiotic class should be taken with food and can cause antabuse-like rxn when taken with alcohol?

Cephalosporins

This antibiotic may produce red/brown urine

Flagyl