Miscellaneous Antibiotics Flashcards
Name the types of Fluoroquinolones
3 most common
3 others
Ciprofolxacin* (Cipro) Levofloxacin* (Levaquin) Moxifloxacin* (Avelox) Gemifloxacin (Factive) Norfloxacin (Noroxin) Oflaxacin (Floxin)
Are FQ bacterocidal or bacteriostatic?
bacterocidal
Describe the Distribution of FQs?
Elimination of FQs?
Good tissue distribution
Good distribution into fluids except CNS
All undergo renal elimination except moxifloxacin
MOA of FQs?
Inhibit DNA gyrase and topoisomerase IV necessary for replication of bacteria
What FQs would cover Aerobic gram negative bacteria?
All fluoroquinolones
What FQs would cover Pseudomonas Aeruginosa?
2
ciprofloxacin and levofloxacin
What FQs would cover Gram positive including Streptococcus spp, (Streptococcus pneumonia)-ear, upper, and lower resp infection
3
Levofloxacin, moxifloxacin and gemfloxacin
What FQs would cover Anaerobic
bacteria?
Moxifloxacin
Clinical uses for FQs?
5
- Urinary tract (DOC)- cipro
- Sexually transmitted
- GI infections
- Traveler’s diarrhea
- Osteomyelitis- good penetration into the bone
Drug of choice for UTIs?
cipro
What FQs (3) are classified as Respiratory FQs and why are they used for this?
FQ’s that have activity against Gm+ organisms including Streptococcus.
Levofloxacin, moxifloxacin and gemifloxacin
What is the BBW on FQs?
What demographics is this increased in?3
Fluoroquinolones, including LEVAQUIN®, are associated with an increased risk of tendinitis and tendon rupture in all ages
60 years of age, in patients taking corticosteroid drugs, and in patients with kidney, heart or lung transplants
SE of FQs?
8
Nausea Diarrhea Dizziness Confusion Tendon rupture QT prolongation- higher risk to go to vtach/death Tendonitis Peripheral neuropathy
What are the common drug interactions for cipro?
4
CYP4501A2 Theophylline, warfarin, tizanidine, propranolol
What drugs all decrease absorption in FQs?
5
Antacids, sucralfate, magnesium, calcium, iron all decrease the absorption of FQs
In which meds do you have to adjust the dose on for FQs with renal considerations?
What other dosing should you be careful about (pts with what?)
Adjust dose for renal failure patients unless using moxifloxacin
Caution when using in patients with history of ventricular arrhythmias secondary to QT prolongation
Dosage forms of FQs?
Can be given oral or IV
FQs contain the only oral agents against what?
Pseudomonas
In what demographics is it contraindicated in?
Why?
Not for use in pregnancy or in children
Pregnancy & lactation = exposure to infant
Pediatrics = arthropathy and osteochondrosis
What is the drug in the sulfonamides class that we talked about?
Sulfamethoxazole/Trimethoprim (SMX-TMP) (Bactrim DS, Septra)
Describe the distribution of Sulfamethoxazole/Trimethoprim (SMX-TMP) (Bactrim DS, Septra)?
What about elimination?
Distribution to body tissues, CSF, pleural fluid, synovial fluid
Eliminated through liver and kidneys
What is the MOA for sulfonimides?
Describe the mechanism in SMX and TMP?
Folic acid synthesis inhibitors
Bacteria need to produce folic acid to survive:
SMX inhibits dihydropteroate synthetase
TMP inhibits dihydrofolate reductase
Clinical uses for sulfas?
5
- Urinary tract infections
- PCP or P. jiroveci pneumonia!!!!
- Toxoplasmosis
- Gram positive and negative infections
- MRSA!!!
Most common side effects with sulfas are?
3
Ones that we need to watch out for???
2
rash, fever and GI symptoms.
Stevens-Johnson syndrome
Hemolytic anemia if underlying G6PD deficiency
Describe the MOA of stevens/johnsons syndrome?
2
- Cell death causes the dermis and epidermis to separate
2. Hypersensitivity reaction of skin and mucous membranes
Describe the drug interactions with Sulfas?
5
Up to 70% protein bound. Displaces other drugs Potentiates the effects of: Warfarin Phenytoin Hypoglycemic agents Methotrexate Beta-blockers
What are sulfas metabolized by?
Where are they excreted?
If CrCl is 15-30 what shouldwe do? What about below 15?
liver
kidney
Reduce dose by 50%
Stop use
Sulfa doasge forms?
What is it most commonly used for?
Pregnancy category?
For oral use only
UTIs
C
Do sulfas cover MRSA?
yes.
MRSA. cellulitis skin infections
What are Nitrofurantion (Macrobid) used for?
Dosage forms?
Only for treatment and prevention of uncomplicated urinary tract infections
PO
How would you describe the absorption of Nitrofurantion (Macrobid) and clearance?
Rapidly absorbed and only in the serum for about 30 minutes.
Cleared renally and is concentrated in the urine
Inadequate drug levels in the bladder if the creatinine clearance is abnormal
At what CrCl level is Nitrofurantion (Macrobid) contraindicated in?
What do we think the MOA of Nitrofurantion (Macrobid) is?
Thought to disrupt bacterial cell wall synthesis through inhibition of bacterial enzymes
Nitrofurantion (Macrobid) is Effective against common organisms that cause UTIs.
What are they?
5
E. Coli Citrobacter Staph saprophyticus Enterococcus faecalis Eneterococcus faecium
Most common side effects of Nitrofurantion (Macrobid)?
Whats the one we have to watch for/ the most dangerous?
Nausea and vomiting
Pulmonary reactions (toxicity)
- Pulmonary infiltrates,
- pneumonitis,
- pulmonary fibrosis
How to the pulmonary reactions manifest in pts with Nitrofurantion (Macrobid)?
How fast is this usually discovered and how do we fix it?
usually manifested by sudden, severe dyspnea, chills, chest pain, fever, and cough
consolidation or pleural effusion
Usually evident within the first week of treatment and reversible when drug discontinued
Resolution often is dramatic
Drug interactions of Nitrofurantion (Macrobid)?
none
Nitrofurantion (Macrobid)
Pregnancy cat?
Except…
Lactation?
B
contraindicated at term (38-42) due to the possibility of causing hemolytic anemia in the newborn due to immature erythrocytes
Dont use
Due to concerns for pulmonary toxicity who do we not use Nitrofurantion (Macrobid) in?
2
Avoid use in older adults
Avoid using for long term suppression of infection
Metronidazole (Flagyl)
treats what kind of infections?
Anti-Anerobic
Describe the metabolism of Metronidazole (Flagyl)?
Absorption?
Distribution?
Metabolized by the liver
Adjust dose with a history of liver failure
Absorbed well PO
Good tissue penetration in most locations
Metronidazole (Flagyl) MOA?
Inhibitor of bacterial protein synthesis.
-Causes DNA strand breakage therefore inhibiting bacterial protein synthesis
Spectrum of activity for Metronidazole (Flagyl) MOA?
Treatment of choice for:
4
Good activity against gram positive and negative anaerobes
Helicobacter pylori
Trichomonas vaginalis
Anerobic infections
Bacterial vaginosis
Trichomoniasis
C. difficile diarrhea
What dosage forms does Metronidazole (Flagyl) come in?
4
Oral
IV
Topical (roseacea)
Intravaginal
BBW for Metronidazole (Flagyl) ?
carcinogenic in mice and rats (see PRECAUTIONS). Unnecessary use of the drug should be avoided.
Most common side effects of Metronidazole (Flagyl)?
3
Ones we should look out for/more dangerous?
3
Nausea, vomiting, abdominal pain and metallic taste
Seizures (high doses) Peripheral neuropathy (prolonged courses) Pancreatitis
Drug interactions for Metronidazole (Flagyl)?
2
Enhances anticoagulant effect of warfarin
Alcohol!!!!!
Flushing, palpitations, nausea, vomiting
Inhibitor of CYP34A so potential for many drug interactions
What drugs would increase the metabolism of metronidazole which decreases the serum concentration and may lead to treatment failure?
3
Phenobarbital, phenytoin, rifampin
