Pharm 2 quiz 2

How does aminoglycoside block bacteria?

* Blocks formation of the 50s and 30s ribosome complex
* Also block translocation

How does macrolides, lincosamides, oxazolidinones and chloramphenicol block bacteria?

* Binds to 50s and block peptide formation

\

What are the 4 tetracycline antibiotics?

* Tetracycline
* Demeclocycline
* Doxycycline
* Minocycline

What are ways of administration for tetracyclines?

* **Orally**
* Topically
* Intravenously

What type of spectrum is tetracycline? Indications?

* Rickettsial disease, H. pylori, animal bites
* Topical: treatment of acne (topical and oral)
* Periodontal disease
* STIs

How does tetracycline work?

* Inhibit binding of transfer RNA to mRNA
* Bacteriostatic
* Selective toxicity: Poor ability to cross mammalian cell membranes

Tetracycline is ___ acting and eliminated in the *____?*

* Short Acting
* Kidney

Demeclocycline is ___ acting and eliminated in the *____?*

* Intermediate acting
* Kidney

Doxycycline and Minocycline is ___ acting and eliminated in the *____?*

* Long acting
* Liver

What is better for absorption in regards to tetracylines?

•Better absorption on empty stomach for the short and intermediate acting agents

What are issues tetracyclines cause during oral administration?

* Incomplete swallowing
* Esophageal irritation

\
(take w water)

What products should you avoid w tetracyclines?

* Ca, Fe, Zinc, MG
* Dairy, Iron, Mg laxatives, antacids, Ca
* Digoxin, Warfarin

\
Wait 2 hrs before eat, or 2 after

What is Doxycyline (vibramycin) used for?

* Lyme disease and chlamydia

What is minocycline (minocin) used for?

* Systemic infection or arthritis
* Vestibular toxicity
* Costly

How are doxycycline and minocycline pharmokineticized?

* May be taken w or w/o food
* Longer half-life or twice daily dosing

What are adverse effects of tetracycline?

* GI irritation, superinfection, discoloration of teeth, disruption in long-bone growth, photosensitivity, hepatotoxicity
* Can cause renal impairment

Who to not use tetracycline with?

* Pregnancy
* Breastfeeding
* Children under 8

What is Tigecycline (Tygacil)? Use?

* Same as tetracyclines but more effective against drug resistant bacteria (+ and -)
* Resistant staph, VRE, PCN resistant pneumonia, c. diff
* E.coli
* Bacteriostatic

When to use Tigecycline (Tygacil)?

Only when other antibiotics are not working

What are adverse effects of Tigecycline (Tygacil)?

* Similar to tetracycline (n/v, photosensitivity, suprainfection (CDAD)
* Pancreatitis
* Avoid in pregnancy
* Can slow clearance of warfarin
* Higher mortality when used for severe infections

What is noteworthy about macrolides?

Prolonged QT

What is Erythromycin?

* Macrolide antibiotic
* Binds to 50s and block peptide chain
* Sometimes as an alternative for PCN allergies

How is erythromycin administered?

* IV
* Oral
* Topically

What is erythromycin more effective against?

More effective against gram-positive than gram-negative

\
* Legionella (legionnaires disease)
* Bordetella pertussis (whooping cough)
* Corynebacterium
* Sometimes chlamydia/pneumonia

What other effects does erythromycin have?

* Promotility effects (sometimes used w metoclopramide)
* GI upset

What are the difference between the two oral erythromycins?

* Food decreases Erythromycin stearate absorption
* Erythromycin ethyl succinate not affected
* Erythromycin STEAR away

What are adverse effects of Erythromycin?

* GI upset is common
* Superinfection and QT prolongation is more serious

What are erythromycin drug interactions?

Less CYP450 inhibition

What is azithromycin (zithromax)? Use?

* Newer Macrolide
* Use for URI, ear infection

What are some interactions of azithromycin?

* Absorption decreased by food but you can still give it
* Don’t give it w antacids (Mg or Al)
* Minimal CYP450 inhibition

How to give azithromycin?

* Can be given IV over 60 minutes
* IV therapy followed by oral

What is clarithromycin (Biaxin)?

* Newer macrolide
* Immediate release tablet and granules for suspension that can be given w/o regard to meals

\
Extended release should be given w meal

What are drug interactions of clarithromycin?

* CYP450 inhibitor
* Warfarin, antiepileptics, cyclosporine, HIV antivirals, oral contraceptives, Statins, theophyline

What is clindamycin? Use?

* Prototype Lincosamide
* Bacteriostatic
* Used for anaerobic infections outside CNS

How to administer Clindamycin?

* IV
* IM
* Oral
* Vaginal
* Topical

What are adverse effects of Clindamycin?

\
Serious adverse effect

* C-diff associated diarrhea
* Cause: superinfection
* Treat w oral vancomycin or metronidazole
* Diarrhea

\

What happens if you administer Clindamycin IV rapidly?

Make cause EKG changes, hypotension, cardiac arrest

What should you teach about clindamycin?

* Can cause diarrhea
* PO- take w water, may give w meals

What is Linezolid (zyvox)? Use?

* Oxazolidinone antibiotic
* Active against multidrug resistance gram + organisms
* MRSA and VRE

How does Linezolid (zyvox) works in the body?

* Blocks early stages of protein making process in bacteria (stops initiation complex)
* Resistance may not develop as quick

How is linezolid (zyvox) administered?

PO or IV

What are adverse effects of Linezolid (zyvox)?

Serious:

* Myelosuppression
* Monitor CBC

Common:

* Nausea, diarrhea, H/A, neuropathy

What are some drug interactions with Linezolid (zyvox)?

* MAOI: HTN crisis
* SSRI: serotonin syndrome

What is Mucipirocin (bactroban)? Use? Admininistration?

* Bacteriostatic inhibitors of protein synthesis
* For MRSA nasal colonization (2x daily for 5 days)
* Impetigo from s. aureus, s. pyogenes, or beta hemolytic strep (three times daily for 10 days)

What are adverse effects of Mupirocin (bactroban)?

* Skin irritation
* HA, rhinitis, congestion, etc. (w nasal administration)

What is retapamulin (altabax)?

* Bacteriostatic inhibitors of protein synthesis
* Topical administration (best for impetigo)

What are adverse effects of retapamulin (altabax)?

Skin irritation

What is Dalfoprostin/Quinuptistin (synercid)?

•bactericidal in combination

When would you use Dalfoprostin/Quinuptistin (synercid)?

* Vancomycin: resistant organisms (especially enteroccci faecium)
* MRSA or highly resistant strep. pneumonie

Can you administer Dalfoprostin/Quinuptistin (synercid) to patients with PCN or cephalosporin allergies?

YASS

What to watch out for w Dalfoprostin/Quinuptistin (synercid)?

* Hepatotoxicity and thrombophlebitis
* Monitor liver enzymes frequently
* Interacts w CYP3A4

What is important about Dalfoprostin/Quinuptistin? (synercid) in IVs?

•Use in a central line

•Flush w dextrose before and after administration

What is chloramphenicol? Use?

* Broad spectrum antibiotic that inhibits protein synthesis
* Use limited for only infections that cannot be treated with safer antibiotics

What are serious adverse effects of chloramphenicol?

* Reversible bone marrow suppression
* Gray syndrome
* Rare but serious side effect that occurs in newborn infants (esp premature babies)
* Aplastic anemia

How is chloramphenicol administered?

* IV
* PO
* Topical (eye infections)

What is ciproflaxicn (cipro)?

•Fluoroquinolones

•bactericidal broad spectrum antibiotic

•inhibits bacterial dna gyrase (needed to replicate)

When will you use ciprofloxacin?

•sinusitis, AOM, UTI, Pneumonia, shigella

•Drug of choice for anthrax

•Topical for conjunctivitis, acute otitis externa, tmpanostomy tube associated otorrhea

How is ciprofloxacin (cipro) administered?

* IV
* PO
* Topical (eye or ear drops)

What are adverse effects of fluorquinolones?

* Gastrointestinal (N/V/D)
* Heachache
* CNS
* Candida pharynx and vagina
* Photosensitivity
* Risk for C. diff

What are SERIOUS side effects if fluorquinolones?

•Prolong QT interval

•Muscle weakness in MG patients

•Aortic Dissection

•Mental Health effects and hypoglycemia → coma

•can cause **permanent** peripheral neuropathy (FDA warning)


1. Can cause tendon rupture (Achilles)
2. Discontinue at first sign of pain or inflammation
3. Patients should not exercise until tendonitis has been ruled out
4. Do not give to children under age 18 w two exceptions

Which drug can cause tendon damage?

Fluorquinolones

What drug can also cause mf aortic dissection?

•Ciprofloxacin fluoroquinolones

* Rare. avoid in those with risk at baseline

What will reduce the absorption of Fluorquinolones?

* Aluminum and magnesium antacids
* Iron salts
* Zinc salts
* Sucralfate
* Milk and dairy and calcium

\
Give meds 6 hrs before cipro or 2 hrs after

What do you need to monitor with fluoroquinolones (cipro)?

* Monitor doses of warfarin and theophylline, others

what are high risk patients for fluoroquinolones?

* History of myasthenia gravis
* >60 yrs
* Renal impairment
* Glucocorticoid therapy
* Transplant patients
* History of hypokalemia
* cardiac history (prolong qt)
* Aortic aneurysm/at risk

What is metronidazole (flagyl) used for?

* Protozoal and obligate anaerobic infections
* Initial treatment of severe infections given IV, then switched to oral

how does metronidazole (flagyl) antibioticize?

* Bactericidal to anaerobic organisms only

How is metronidazole (flagyl) given?

PO or IV

What are some interactions with metronidazole (flagyl)?

* Liver metabolism: Warfarin, lithium, phenytoin, others — levels increased so monitor
* Ketoconazole: increases metronidazole levels

What are some contraindications w metronidazole (flagyl)?

* Crossed placenta and BBB
* avoid in 1st trimester, caution in 2nd and 3rd
* Breastfeeding
* if single dose therapy: ok to breastfeed after 12-24 hours post dose

What are adverse effects of metronidazole (flagyl)?

\-lowers seizure threshold

\-gi

\-HA, dizziness

\-Red brown urine

\-metallic taste

\-thrombophlebitis w IV use

\-Disulfiram-like reaction w concomitant alcohol

\-Stevens Johnson syndrome (1st sign: flu like symptoms)

What is daptomycin (cubicin)? Use?

\-unique MOA: bactericidal against all gram +, including MRSA

\
\-Used for systemic bloodstream infections of Staph. Aureus

\-Skin infections for many gram + organisms

\-Testing for other uses

How is daptomycin administered?

IV administration

Is there a high or low risk of resistance with Daptomycin (cubicin)?

Very low risk of resistance

What are adverse effects of Daptomycin (cubicin)?

Common: GI effects, headache, insomnia, local IV site

Rare: myopathy and eosinophilic pneumonia

What are drug interactions with daptomycin (cubicin)?

Caution with simvastatin (zocor) and tobramycin

What is rifampin (rifadin)? Use?

\-broad spectrum drug

\-primarily for tuberculosis, neisseria meningitidis

\

Is rifampin easily resistsed?

Yes, **high** risk of resistance

What is rifaximin (xiafaxan)? 3 Uses?

* Similar to rifampin (oral analog of rifamipin)
* 3 uses:
* Traveler’s diarrhea
* Prevention of hepatic encephalopathy
* IBS-D

\

How is rifaximin (xifaxan) administered?

Oral administration w food

what are adverse effects of rifaximin (xifaxan)?

* GI effects and hypersensitivity reactions

When should you not administer rifaximin (xifaxan)?

Do not administer to pregnant or breastfeeding patients

What is fidamoxicin (dificid)? Uses?

* narrow spectrum antibiotic


* Alternate treatment to vancomycin for c. Diff

How is fidamoxicin (dificid) administered?

* orally with food

What are adverse effects of fidaxomicin (dificid)?

* GI effects → N/V abdominal pain
* Gi hemorrhage
* Anemia and neutropenia

What are aminoglycosides? Use?

* Bactericidal narrow spectrum antibiotic
* Used primarily for aerobic gram negative
* \
* E. coli
* Klebsiella pneumoniae
* Serratia marcescens
* Proteus mirabilis
* Pseudomonas aeruginosa

\

how does aminoglycosides work on the body? Post effect?

* disrupts bacterial protein synthesis
* Bactericidal
* Post antibiotic effect: bactericidal effects persists for several hours after serum levels have dropped below minimal bactericidal concentration

\

What is gentamicin?

* prototype of aminoglycosides
* Effective in management of serious infections of aerobic gram negative organisms
* Not good for anaerobic

What is noteworthy about aminoglycosides (mycin)?

Can cause serious injury to ears, kidney

what are pharmocokinetics of gentamicin?

* does not penetrate the CNS
* it has poor oral absorption

What are serious adverse effects of gentamicin?

* nephrotoxicity
* Ototoxicity
* Neuromuscular blockade (can mimic)
* -inhibits neuromuscular transmission causing paralysis, resp depression
* -do not give with a neuromuscular blocker, genérel anesthetic
* Treat w iv calcium gluconate

How should you dose aminoglycosides?

* daily or 2-3 smaller doses

How should you monitor aminoglycosides?

* monitoring serum drug levels
* Peak/trough monitoring
* Monitoring depends on dosing plan
* Narrow therapeutic range

What are reasons if varying serum levels despite same dosage?

* body fat
* Age
* Pathophysiology (kidney dysfunction)
* Fever
* Edema/dehydration

When should you be cautious w aminoglycosides ?

* impaired renal function
* Taking another nephrotoxic medication
* Taking another ototoxic medication

How to reduce toxicity (aminoglycosides?)

1. Identify patients at high risk for adverse effects
2. Keep patients well hydrated
3. Use caution w. Concurrent administration of diuretics
4. Give medications for no longer than 10 days unless absolutely necessary
5. Detect adverse effects early and reduce dosage or discontinue

Amo-NO (aminoglycosides)

* no protein synthesis
* No use in pregnancy
* Gram neg. Organisms (aerobic)
* Ototoxic
* Neohrotoxic
* No hear, no pee, no feel

What is Isoniazid (Laniazid)? Use?

* Primary agent for TB
* Bactericidal

What are adverse effects of Isoniazid (Laniazid)?

* Peripgeral neuropathy (pyridoxine vitamin B6
* Hepatotoxicity
* CNS effects

What are drug interactions with Isoniazid (Laniazid)?

* Inhibitor of P450
* Increases phenytoin, diazepam, carbamazepine
* **ALCOHOL**