Part 7 Flashcards
B lactam antibiotics mechanism of action
Disrupt bacterial cell wall causing them to take up water and burst through inhibiting transpeptidases that catalyze cell wall formation and activation of autolysins that cleave bonds in wall by binding Penicillin binding proteins
B-lactamases definition
Coded for by a plasmid between bacteria to promote synthesis of proteins that release into the space around them to cleave certain PCNs
PCN drug interactions (3 to know)
1) probenecid - delay excretion
2) aminoglycosides - inhibed by PCNs and need to be administered separately
3) Bacteriostatic antibiotics - PCNs work best on fast dividing
Anti pseudomonal penicillin name
-Piperacillin
1st -5th gen cephalosporins trend (3)
- 1st gen most susceptible to B lactamases, 5th is highly resistant
- Increased activity against gram - bacteria
- increased ability to reach csf
List example 1st-5th gen cephalosporins
1) cephalexin (keflex)
2) Cefaloxin
3) ceftazidime, cefdinir (omnicef), or ceftriaxone (roecephin)
4) cefipime
5) ceftaroline (effective gainst MRSA)
Disulfiram like reaction can occur with metronidazole. What other drug class can it possibly occur with?
Cephalosporins (apparently)
Carbapenems drug class and MOA
B-lactam antibiotis that like penicillins and cephalosporins, inhibit bacterial cell wall synthesis, have very broad antimicrobial spectrum
Vancomycin adverse effects (3)
- Renal failure (dose related)
- Ototoxicity
- Red man syndrome (histamine release resulting in rashes, flushing, potential to go into shock)
These two antibiotic classes should never share an IV bag
PCNs and aminoglycosides
What is the broadest spectrum aminoglycoside
Amikacin
Tetracyclines mechanism of action
Broad spectrum antibiotics that inhibit protein synthesis at the ribosome 30s subunit after being transported via energy dependent processes
Tetracycline absorption
Via GI, but form insoluble chelates with cations preventing absorption and thus require administration 1-2 hours after ingestion of a chelate
Tetracycline common side effects (3)
- GI upset
- bones and teeth coloraion
- photosensitivity
Macrolides mechanism of action
Broad spectrum antibiotics that act by inhibiting bacterial protein synthesis, bind 50S ribosome and are bacteriostatic
Macrolide common adverse effects (2)
-GI effects
-QT prolongcatoin which can precipitate torsades de pointes
Chloramphenicol MOA and why is it not commonly used? What is it drug of choice for? What is another condition this is linked to?
Similar to a macrolide, not commonly used because has adverse effect of aplastic anemia requiring close monitoring, is still sometimes used as drug of choice in eye infections and typhoid or meningitis. In pediatrics, this is linked to gray baby syndrome which is where it builds up to toxic levels causing abdominal distension, gray coloration of skin, possibly shock and death
Fluorquinolones mechanism of action
Passive diffusion, inhibit DNA replication on bacterial gyrase and toposioromase, rapidly bactericidal
3 common B-lactamase inhibitors to be combined with penicillinase sensitive PCN
1) clavulanic acid
2) tazobactam
3) sulbactam
IV calcium gluconate with ceftriaxone injection
contraindicated due to calcium precipitate formation
Teicoplanin
Similar action and structure to vancomycin, but largely devoid of any ADRs
Fosfomycin
Similar action and structure to vancomyscin, often used in uncomplicated UTI
Telavancin
Similar action and structure to vancomycin, treats complex skin infections and causes taste disturbance and foamy urine
4 tetracyclines available
1) tetracycline (short acting, no food)
2) denecocycline (medium acting, no food)
3) doxyxcline(long acting, no food)
4) minocycline (long acting, food okay)
Fanconi syndrome
A type of Ingestion of proximal renal tubular acidosis sometimes due to ingestion of outdated tetracycline can cause proximal renal tubular dysfunction leading to renal failure
Name the 3 macrolides
1) erythromycin
2) azithromycin
3) clarithromycin
Clarithromycin and azithromycin are often prescribed over erythromcyin because of one distinct advantage
They do not typically cause nausea and diarrhea
Clindamycin mechanism of action
Inhibition of the 50S ribosome to prevent protein synthesis
Clindamycin ADR
Can cause psudomembranous colitis from Cdiff
Dalflopristin/Quinipristin mechanism of action and what do they treat?
Streptogamins, together become bactericidal, treat VRE and MRSA
Linezolid mechanism of action, what does it treat and what is an ADR
Binds 23s portion of 50s subuinit of ribosome, cross resistance therefore unlikely, treates VRE and MRSA, myelosupression
Metronidazole spectrum
Protozoa or anaerobic bacteria, DOC for Cdiff, amoeba, and trichomonas vaginalis
Metronidazole mechanism of action
Taken up passively, converted to active form in anaerobic bacteria, break up DNA helical structure
Metronidazole ADRs (3)
Neurologic effect, urine darkening, disulfarim like rxn
Sulfonamides mech of action
Inhibition of synthesis of folic acid by binding where PABA does to be bacteriostatic
Sulfonamide spectrum
Broad, gram + including MRSA and some gram neg, DOC for acute UTI
Sulfonamide ADRs (5)
- Photosensitivity
- drug fever
- Steven Johnson syndrome (widespread lesions)
- acute hemolytic anemia
- Kernicterus (bilirubin buildup in newborn brain
Osteon/Haversion canal definition
Hollow tubes in cortical bone that serves as passage for the vessels to supply the structure
Lamella definition
One of the layers of an osteon/havarsion system that radiate outward from the canal center
Lacunae definition
A hole in hydroxapatite matrix that stores osteocytes (inactive form of osteoblasts)
Osteoblast
Functionally lay down hydroxapatite matrix forming cortical bone, stimulated by calcitonin and inhibited by PTH
Osteoclast
Functionally remove hydroxapatite matrix by removing cortical bone via phagocytosis, inhibited by calcitonin
Low blood calcium causes release of ____, high blood calcium causes release of ______
PTH, calcitonin
Osteomalacia (rickets disease in children)
Caused by inadequate vit. D intake (and treated with supplement), causes weakness and bone pain
Ligament definition and function
Attachment of tissue from bone to bone, function to stabilize the joint and to facilitate the desired motion set by the ligament’s orientation
Sacrotuberous ligament insertion and function
Insertion: Sacrum to ischial tuberosity
Function: Houses a nerve, intertwined with the sacrospinous ligament
Sacrospinous ligament insertion and function
Insertion: Sacrum to ischial spine
Function: Anterior to the sacrotuberous ligament, forms the greater sciatic foramen, functionally prevents the ileum from sliding posterior to sacrum, intertwined with sacrotuberous ligament
Sacroiliac ligament (SI joint) insertion and function
Insertion: Sacrum to Iliac
Function: Tightly intermingle the sacrum with the ileum
Acetabular labrum insertion and function, does it often cause symptoms if torn?
Insertion: Femur head to acetabolum of pelvic bone
Function: Tightly wrap around the ball and socket joint of the femur with the pelvic girdle.
It does not often cause symptoms when torn.
Iliofemoral ligament
Insertion: Anterior inferior iliac spine to femur
Function: Strongest ligament in the body, Y ligament, helps us remain upright while walking
Ischiofemoral ligament insertion (no function given)
Insertion: Ischium to femur
Function: Not much to say
Pubofemoral ligament insertion and function
Insertion: Superior ramus of the pubis to the femur
Function: prevents hyper-abduction at the hip joint (god help when you do the splits yo)
Anterior cruciate ligament insertion and function
Insertion: Femur to tibia, crossing anteriomedially over the PCL
Function: limit anterior displacement of tibia
Posterior cruciate ligament insertion and functiom
Insertion: femur to tibia, crossing posteriolaterally behind the ACL
Function: limit posterior displacement of tibia
Medial collateral ligament insertion and function
Insertion: Medial femur to tibia
Function: prevent medial directed force on the tibia and femur
Lateral collateral ligament insertion and function
Insertion: lateral femur to lateral fibula
Function: prevent lateral directed force on fibula and femur
Medial/Lateral Meniscus insertion and function
Insertion: between tibia and femur
Function: Shock absorber, provide stability
Anterior tibiofibular ligament insertion (no function listed)
Insertion: anterior face of inferior space between tibia and fibula
Function: mmmk
Anterior talofibular ligament insertion and function
Insertion: Lateral malleolus to anterior talus
Function: Most commonly injured in an ankle sprain, prevents foot from sliding forward during a sprain