Infectious Disease Flashcards
1
Q
Gram positive cocci in clusters likely organism?
A
Staphylococcus spp. including MRSA and MSSA
2
Q
Gram positive cocci in pairs or chains likely organisms? 3 specifically
A
- Strep pneumoniae (diplococci)
- Streptococcus spp. (including Strep. Pyrogenes)
- Enterococcus spp (including VRE)
3
Q
Gram positive rods likley organisms?
Lester was a positive nimRod
A
- Listeria monocytogenes
4
Q
Gram positive spores anaerobes?
PAC
A
- Peptostreptococcus
- Actinomyces spp
- Clostridium spp
5
Q
Atypicals which dont stain well
4
A
- Chlamydia
- Legionella
- Mycoplasma pneumoniae
- Mycobacterium tuberculosis
6
Q
Gram negative (pink)
Cocci
A
- Neisseria spp
7
Q
Gram negative rods
enteric colonization
PEKSEC
A
- Proteus mirabilis
- E. Coli
- Klebsiella
- Serratia
- Enterobacter cloace
- Citrobacter spp
8
Q
G (-) rods that do not colonize in the gut
PHP
A
- Pseudomonas aerogenosa
- Haemophilus influenzae
- Providencia spp
9
Q
G - rods curved or spiral shaped
5
A
- H. pylori
- Campylobacter spp
- Treponema
- Borrelia
- Leptospira
10
Q
Gram - coccibacilli ABM
A
- Acinetobacter baum
- Bordetella pertussis
- Moraxella catarrhalis
11
Q
Gram - anaerobes
Baby Penguins are Mean and dont breathe
A
- Bacteroides fragilis
- prevetella
12
Q
What two classes can sometimes be used synergistically to treat gram positive endocarditis?
A
AGs and beta-lactams
Beta-lactam opens the cell up so the AG can get to the ribosome and be effective
13
Q
Antibiograms
A
Provide susceptibility patterns usually over one year
Aid in selecting empiric therapy and track resistance over time
14
Q
Mechanisms of Resistance
A
Intrinsic resistance: natural to the organism
Selection pressure: susceptible bacteria are killed leaving only resistant bacteria
Enzyme Inactivation: Beta lactamases, extended spectrum beta lactamases (treated with carbapenems or newer cephalosporin beta lactamase inhbitors)
Carbapenem-resistant enterobactericae (MDR gram negative organisms): produce carbapenemase: combination treatment with polymyxins
15
Q
Common Resistant Pathogens 7
Kill Each and Every Strong Pathogen
A
- Klebsiella pneumonae (ESBL, CRE)
- Eschericha Coli (ESLB, CRE
- Acinetobacter baumannii
- Enterococcus faecalis, Enterococcus faecium (VRE)
- Staph aureus (MRSA)
- Pseudomonas Aeroginosa
16
Q
Folic Acid Synthesis Inhibitors
A
- Sulfonamides
- Trimethoprim
- Dapsone
17
Q
Cell wall inhibitors:
BMVDTO
A
- Beta-lactams (penicillins, cephalosporins, carbapenems)
- Monobactams (aztreonam)
- Vanc, dalbavancin, televancin, oritavancin
18
Q
Protein synthesis inhibitors: 7
AMTCLTQ/D
A
- AGs
- Macrolides
- Tetracyclines
- Clindamycin
- Linezolid, tedilozid
- Quinu/Dalfo
19
Q
Cell membrane inhibitors:
PDTO
A
- Polymyxins
- Daptomycin
- Televancin
- Oritavancin
20
Q
DNA/RNA Inhibitors
A
- Quinolones (DNA gyrase, topoisomerase IV)
- Metronidazole, tinidazole
- Rifampin
21
Q
Hydrophilic agents 5 and attributes
A
- Beta lactams
- AGs
- Glycopeptides
- Dapto
- Polymyxins
- Small Vd: Poor tissue penetration
- Renal elimination: nephrotoxicity
- Low intracellular concentrations: Not active against atypicals
- Increased clearances or distribution in sepsis: consider loading dose and aggresive dosing in sepsis
- Poor-moderate bioavailability Not used PO or IV PO ratio is not 1:1
22
Q
Lipophilic Agents 6 and attributes
QMRLTC
A
- Quinolones
- Macrolides
- Rifampin
- Linezolid
- Tetracyclines
- Chloramphenicol
- Large Vd: great tissue penetration
- Hepatic metabolism: hepatotoxic and DDI
- Achieve intracellular concentrations: active against atypicals
- Clearance and distribution is not changed by sepsis
- Great bioavailability: IV:PO is usually 1:1
23
Q
Concentration dependent killing
A
AGs, quinolones, dapto
can be dosed less frequently and at higher doses to maximize concentration above the MIC
24
Q
Time dependent killing
A
Beta lactams
Dose more frequently to maximize time above MIC
25
AUC: MIC abxs 4
Vanc, macrolides, tetracyclines, polymyxins
26
As a class beta lactams are not active against?
Atypicals and MRSA
27
Natural Penicillin coverage
* Gram:+ cocci: Streptococci and Enterococci DO NOT COVER STAPH, and gram + anaerobes
* Little activity for gram negative
28
Aminopenicillins
* Strepto, entero, and gram positive anaerobes (mouth flora)
* Addition of amino group gives them gram negative coverage HNPEK, Haemophilus, Neisseria, Proteus, E. Coli and Klebsiella
29
Aminopenicillins in combination with Beta-lactamase inhibitors have what increased coverage?
* Covers MSSA
* more resistant gram negative HNPEK strains and gram negative anaerobes (B.fragilis)
30
Extended spectrum penicillin coverage
* Pip/tazo
* expanded coverage of gram negative bacteria including citrobacter, acinetobacter, providencia, enterobacter, serratia CAPES and Pseudomonas aeroginosa
31
Antistaph penicillins coverage
* cover strep
* and enhanced activity against MSSA
* No enterococcus activity or gram (-) and anaerobes
32
natural penicillins 2
Penicillin V, Penicllin G
33
Aminopenicillins 4
Amoxicillin
Amoxicillin/Clavuanate (augmentin)
Ampicillin
Amp/sulbactam (Unasyn)
34
Extended Spectrum Penicillins
Piperacillin/Tazobactam
35
Antistaph penicillins
Dicloxacillin
Nafcillin (only injection)
Oxacillin (injection)
36
What natural penicllin in not for IV use and why
Pen G benzathine not for IV use causes cardiorespiratory arrest
37
Augmentin and Unasyn contraindication
* Hx of cholestatic jaundice or hepatic dysfunction associated with previous use
38
Contraindications for penicillins
Severe renal impairment CrCl \< 30 mL/min do not use ER amoxicillin and augmentin XR or 875 mg strength of amox/clav
39
Side effects of beta lactams
Seizures with accumulation, GI upset, diarrhea, rash, hemolytic anemia increased LFTs, myelosupression
40
Beta lactam monitoring?
Renal function, anaphylaxis with first dose, CBC LFT, with prolonged course
41
Beta lactam notes
Aminopenicllins
* Amp PO is rarely used due to bioavailability amoxicillin is preferred if switching to PO
* IV amp and unasyn should be diluted with NS only
42
Extended spectrum notes
* 65 grams Na per 1 gram piperacillin
43
Antistaph penicillin notes
Preferred for MSSA soft tissue, bone and joint, endocarditis, and bloodstream infections
Nafcillin is a vesicant central line adminitration is preferred
If extravesication occurs use cold packs and hyaluronidase injection
44
Pen drug interactions
* Probenecid can increase levels sometimes used intentionally
* Except nafcillin and dicloxacillin beta lactams can increase the anticoagulative effects of warfarin by inhibiting vit K production
* Can decrease the serum concentrations of mycophenolate active metabolites due to impaired enterohepatic recirculation
45
Outpatient Peniciillins
* Penicillin VK: first line for strep throat, and mild nonpurulent skin infections (no abcess)
* Amoxicillin (Moxatag): first line for acute otitis media, DOC for infective endocarditis prophylaxis befor edental procedure, used in H.Pylori treatment
* Augmentin: First line for acute otitis media, use the lowest dose of claulanate to reduce diarrhea
46
Inpatient Pareneteral Pens
* Pen G Benzathine: DOC for syphilis, not for IV use can cause death
* Pip/Tazo (Zosyn): Only penicillin active against pseudomonas, extended infusions (4 hours) can be used to maximize Time\>MIC
* Nafcillin, Oxacillin and Dicloxacillin: Cover MSSA not MRSA, no renal dose adjustment needed
47
As a class cephalosporins are not active against?
Enterococcus or atypical organisms
48
First gen cephalosporins: Coverage and Drugs
Cefazolin and Cephalexin (keflex)
* Great G(+) cocci coverage (strepto and staph) preferred when a ceph is used for MSSA infections
* Have mild activity with g(-) rods Proteus, E.Coli, Klebsiella (PEK)
* Worser G - coverage compared to 2nd 3rd and 4th
49
Second-gen types and coverage
* 2 types
* Cefuroxime covers staph, more resistant strains of S. pneumo plus Haemophilus, Neisseria, Proteus, E. Coli and Klebsiella (HNPEK)
* Cefotenan and cefoxitin have good coverage for gram negative anaerobes (B. Fragilis)
50
Third Generation cephs 2 types
* Group 1: ceftriaxone and cefotaxime, cover more resistant streptococcus (S. Pneumo and viridans group strepto), MSSA, gram positive anaerobes (mouth flora) and more resistant strains of HNPEK
* Group 2: Ceftazidime lacks gram positive activity but covers pseudomonas
* Newer beta lactamase combo, ceftazidime/avibactam and ceftolozane/tazo which have activity against MDR Pseodomonas and MDR gram negative rods
51
4th generation cephs
* Cefepime only
* broad gram negative coverage (HNPEK, CAPES and Pseudomonas)
* G + activity similar to ceftriaxone
52
Fifth gen cephs
* Ceftaroline
* g - like ceftriaxone but broad g+ activity
* It is the only beta lactam that covers MRSA
53
Ceftriaxone contraindications?
* hyperbilirubinemic neonates (causes biliary sludging), concurrent use with calcium containing IV products in neonates \<=28 days old
* No renal adjustment needed
54
Cephalosporin warnings
Side effects, monitoring and notes
* Anaphylaxis
* Some drugs can increase INR in patients taking warfarin
* Cross-sensitivity \<10% with PCN allergy do not use in pt with type 1 allergy (swelling, angioedema, anaphylaxis)
* Cefotetan: has N-methylthiotetrazole, NMTT or 1-MTT, which can increase the risk of bleeding and cause disulfram like reaction with alcohol ingestion
* SEs: Seizures with accumulation, GI upset, diarrhea
* Monitor renal function, signs of anaphylaxis at 1st dose, CBCs and LFTs
* Ceftriaxone: No renal adjustments
* Cefixime available in chewable
* Ceftaz/avibactam covers some carbapenem resistant Enterobacteriacea (CRE)
55
Drug interactions with cephalosporins
* cefuroxime, cefpodoxime, cefdinir, and cefditoen should be separated by 2 hours from short acting antacids. PPIs and H2RAs should be avoided
56
Outpatient Oral: 1st gen
* Cephalexin (Keflex)
* Common uses: skin infections (MSSA), strep through
57
Outpatient Oral 2nd generation
* Cefuroxime
* Acute otitis media, CAP, sinus infection (if antibiotic is indicated)
58
Outpatient Oral 3rd gen
* Cefdinir (Omicef)
* CAP, sinus infection
59
Inpatient pareneteral 1st gen
* Cefazolin
* Surgical prophylaxis
60
Inpatient 2nd gen
* Cefotetan and Cefoxitin
* Anaerobic coverage (B.fragilis)
* Surgical prophylaxis in colorectal procedures
* Cefotetan can cause disulfram like reaction with ALCOHOL ingestion
61
Inpatient 3nd gen
* Ceftriaxone and Cefotaxime
* CAP, meningitis, SBP, pyelonephritis
* Ceftriaxone no renal adjustment
* Do not use ceftriaxone in neonates 0-28 days
62
Inpatient 3rd and 4th gen
* Ceftazidime and Cefepime (4th)
* Active against pseudomonas
63
Cephs with beta lactamases
* Ceftolozane/Tazo and Ceftazidime/Avibactam
* Used for MDR gram-negative organisms including Pseudomonas
64
Ceftaroline?
* 5th gen
* Only beta-lactam active against MRSA
65
What do carbapenems reserved for?
Drug interactions?
* MDR gram-negative infections
* Can decrease valproic acid concentrations
* Caution in patient with risk of seizure and when combined with other drugs that lower seizure threshold (ganciclovir, quinolones, bupropion, tramadol)
66
What do carbapenems not cover?
How are they administered?
* Atypicals, VRE, MRSA, C. DIff, Stenotophomonas
* Ertapenem does not cover Pseudomonas, Acinetobacter, or Enterococcus (**E**rt**AP**enem) PEA
* All IV erta should be diluted with normal saline
67
What carbapenem should not be used in pneumonia?
Allergy?
* Doripenem
* Dont use in patients with PCN allergy cross-sensitivity is as high as 50%
68
Class effects of carbapenems?
Common uses of carbapenems?
* All cover ESBL-producing organisms
* All cover pseudomonas except ertrapenem
* Dont use in PCN allergy
* Seizure risk with higher doses, renal failure, or use of imipenem/cilastatin)
* Polymicrobial infections: (mod-severe diabetic foot infections)
* Empiric therapy when resistant organisms suspected
* resistant pseudomonas or Acinetobacter infection
69
Monobactam coverage and drug?
Aztreonam
* Covers many gram negative organisms including pseudomonas
* No gram positive or anaerobe coverage
70
What Beta-lactams have Pseudomonas Coverage? 5
1. Pip/Tazo (zosyn)
2. Ceftazidime/ Aztreonam
3. Cefepime
4. Ceftaz/Avibactam, Ceftolozan/Tazobactam
5. Imipenem/citastatin, miropenem, doripenem
71
What do aminoglycosides cover? What is their MOA?
* bind to the ribosome, which interferes with bacterial protein synthesis
* Primarily cover pseudomonas
* gentamicin and streptomycin are used synergistically with beta-lactams and vanc when treating gram-positive infections enterococcal endocarditis
* Streptomycin and amikacin are used as second line treatment for mycobacterial infections
* Plazomicin is only indicated for complicated UTIs and pylenephritis
72
Information on extended interval dosing with AGs
* Less dose accumulation
* Reduces nephrotoxicity and cost
73
Good and Bad news about AGs?
* Kill gram-negatives fast
* concnetration dependent killing and have a post antibiotic effect
* BAD
* They have notable renal toxicity renal and ototoxicity
74
AG dosing
if underweight
if obese use adjusted BW
75
Renal dosage adjustments for AGs traditional dosing
* starting at \<60 do q12
76
Contraindications for extended interval dosing
* Pregnancy, ascites, burns, cystic fibrosis, CrCl \< 30 (including ESRD and on dialysis)
77
AGs Boxed warnings, warnings, and side effects
* Nephro and ototoxicity, avoid use with neuro or nephrotoxic drugs: neuromuscular bloackade and respiratory paralysis, fetal harm if given in pregnancy
* Use caution in pts with impaired renal function, in elderly and those taking nephrotoxic drugs (ampho B, cisplatin, polymyxins, NSAIDs, cyclosporine, loop diuretics, radio contrast dye, tacrolimus, and vanc)
* nephro, oto, vesibular balance issues
78
What AG has the broadest spectrum of acitivity?
Amikacin
79
AG monitoring
* drug levels, renal function
* Traditional dosing: draw a trough level right before or 30 minutes before the 4th dose, draw a peak after the 30 minute drug infusion
* Extended interval: draw a random level per the timing on the nomogram
* Plazomicin: draw a trough concentration 30 minutes before the 2nd dose goal trough: \<3 mcg/mL
80
Traditional dosing trough goals for AGs
Gentamicin gram negative: \<2 mcg/mL
Tobramycin: \<2mcg/mL
81
What graph is used for extended interval AG dosing?
Hartford nomogram
82
Quinolones mechanism and type of bacterial activity
Spectrum?
* Inhibit bacterial DNA topo IV and DNA gyrase (Topo II)
* Concentration dependent killing
* Broad, gram-negative, positive and atypical pathogens
83
What 3 quinolones are considered respiratory quinolones and why?
* Gemifloxacin, levofloxacin, and moxifloxacin
* Have enhanced coverage against S, Pneumo and atypicals
84
What quinolones have enhanced activity against gram negatives? 2
Cipro and levofloxacin
Including Pseudomonas
typically used in combination with another abx (beta-lactams) when treating pseudomonas infections empirically
85
What is the only quinolone that cannot be used for UTIs?
Moxifloxacin
Also has enhanced gram-positive coverage and anaerobic acitivty can be used only when treating mixed infections like intraabdominal infections
86
Newer quinolone coverage and
Delafloxacin: approved fro skin infections active against MRSA
Other quinolones should be avoided to treat MRSA due to risk of resistance
87
Quinolone boxed warnings
* Tendon inflammation and rupture within hours to days of starting the medication or up to several months, risk increases with use of steroids, in organ transplant, age \>60,
* Peripheral neuropathy
* CNS seizures caution in pts with CNS disorders or drugs that cause seizures
* Avoid in pts with myasthesia gravis
* Last line for: Acute bacterial sinusitis, acute exacerbation of chronic bronchitis, and uncomplicated UTIs (except moxi)
88
Ciprofloxacin contraindications
Concurrent administration of tizanidine
89
Quinolone warnings
* QT prolongation: Highest risk with moxi, avoid in pts with known QT prolongation or those with added risk (hypokalemia, and other drugs that can prolong QT, including class Ia and III antiarrythmics)
* Hypo and hyperglycemia (hypo can cause coma)
* Psychiatric disturbances agitation, diorientation, lack of attention)
* Avoid systemic quinolones in children
* Other: photosensitivity, hepatotoxicitym crystalluria (stay hydrated)
90
Quinolone notes
* Cipro suspension shake vigourously for 15 seconds before use. Do not put through an NG tube
* Cipro can crush immediate release
* Moxi does not have adequate concentrations in urine to treat UTIs
91
Quinolone take aways 12
* Respiratory Quinolones
* Gemifloxacin, Levofloxacin, moxifloxacin
* Used for pneumonia (reliable S. Pneumo activity)
* Antipseudomonal quinolones:
* Cipro, Levo
* Used for Pseudomonas infections (including pneumonias), UTIs, intraabdominal infections, travelers diarrhea (without dysentery)
* Moxifloxacin
* Only quinolone that is not renally adjusted
* Do not use to treat UTIs
* IV:PO ratio 1:1 for levo and moxi
* Profile review tips
* Caution with CVD, decrease K/Mg and with other QT prolonging drugs (azole antifungals, antipsychotics, methadone, macrolides)
* Avoid in patients with a seizure hx or if using seizure meds
* Avoid in children
* Watch for tendon rupture, neuropathy, CNS, or psychiatric SEs
* Counseling:
* Avoid sun exposure, separate for cations, monitor blood glucose in DM patients
92
Quinolone Drug Interactions: 7 points
* Antacids and other polyvalent cations (mg, aluminum, Ca, Iron, zinc), MVM, sucralfate, and bile acid resins can chelate and inhibit quinolone absorption
* Lanthanum carbonate: (Fosrenol) and Sevelamer (Renagel) can decrease serum concentrations of oral quinolones, separate by at least 2 hours before, or 2 hours after (lanthanum) or 6 hours after (sevelamer)
* Can increase the effects of warfarin
* Can increase the effects of sulfonylureas, insulin, and hypoglycemic drugs
* Caution with CVD decrease K and Mg and with other QT prolonging medications (azoles, antipsychotics, methadone, macrolides)
* Probenecid and NSAIDs can increase quinolones
* Ciprofloxacin is P-glyp
93
Macrolide MOA and coverage
* bind to the 50S ribosomal subunit resulting in inhibition of RNA-Dependent protein synthesis
* Great coverage against Atypicals (legionella/chlamydia, mycoplasma, and Mycobacterium avium complex and Haemophilus.
* Treatment options for CAP, upper and lower respiratory tract infections, and certain sexually transmitted diseases (chlamydia, gonorrhea)
94
Azithromycin (Zithromax, Z-pak) Dosing
* 500 mg day 1 then 250 days 2-5
* Tri-pak: 500 mg daily for 3 days
95
Macrolides 3 names and brands
Contraindications
Warnings
SEs
* Azithromycin (Zithromax, Z-Pak), Clarithromycin (Biaxin), Erythromycin (E.E.S., Ery-Tab)
* Contraindications:
* History of cholestatic jaundice/hepatic dysfunction with prior use
* Clarithromycin (Biaxin) and Erythromycin (E.E.S., Ery-Tab) do not use with lovastatin or simvastatin, pimozide, ergotamine or dihydroergotamine
* Clarithromycin (Biaxin): concurrent use with colchine in patients with renal or hepatic impairment, hx of QT prolongation or ventricular arrhythmias
* Warnings:
* QT prolongation (highest risk with erythromycin) avoid in patients with known QT prolong, or those with additive risk (hypokalemia, use of other drugs that prolong QT, including class Ia and III antiarrhythmics
* Hepatotoxicity: use caution in patients with renal disease
* Exacerbation of myasthenia gravis
* Clarithromycin (Biaxin) caution in patients with CAD (increased mortality has been seen)
* SEs:
* GI upset (diarrhea, ab pain, taste perversion, ototoxicity (reversible and rare), severe but rare skin reactions (SJS, TEN, DRESS)
96
What macrolide needs dosage adjustments and what is the cut off?
All others do not
Clarithromycin (Biaxin) CrCl \< 30
97
Macrolide Drug Interactions:
* Erythromycin and Clarithromycin are major substrates of CYP3A4 and 3A4 inhibitors. Medications metabolized by 3A4 may need to be avoid (simvastatin and lovastatin)
* Examples: apixaban, colchine, dabigatran, rivaroxaban, theophylline, and WARFARIN
* Azithromycin: substration of 3A4 and inhibitor of 1A2 and 1-gp: not as significant DIs
* All macrolides: use caution in patients with CAD decreased potassium and mg and with other QT prolonging drugs
98
Common uses of Macrolides: 4 bullets
Common dosing:
* All: CAP and as an alternative to beta-lactams for strep throat
* Azithromycin: COPD exacerbations, monotherapy for chlamydia, combo therapy for gonorrhea, and prophylaxis for MAC, it is the drug of choice for severe travelers diarrhea, (including dysentery, diarrhea with bloody stools)
* Clarithromycin treats H.Pylori
* Clarithromycin causes the most GI upset due to increased gastric motility
* Dosing
* Two 250 mg tabs PO 1 day then 250 daily for 4 days
* QT: caution in patiens with CAD, and when taking other QT drugs, low K/mg
* Drug interactions:
* Clarithromycin and Erythromycin are strong 3A4 inhibitors, lovastatin and simvastatin are contraindicated (increased muscle toxicity)
99
Tetracycline MOA, indications
* inhibits bacterial protein synthesis by reversibly binding to the 30S ribosomal subunit
* Doxycycline: has broader indications
* Including respiratory tract infections (CAP), ticke-borne rickettsial disease, spirochetes and sexually transmitted disease (chlamydia, gonorrhea)
* Doxy is an option for mild skin infections caused by CA-MRSA and VRE UTIs
* Minocycline is often preferred for skin infections, including acne
* Tetracyclines cover many gram-positive bacteria (Staph, Strep, Enterococci, Nocardia, Bacillus, Propionbacterium spp). Gram-negative bacteria including respiratory flora (Haemophilus, Moraxella, and atypicals) and other unique pathogens (spirochetes, rickettsia, bacillus anthracis, treponema)
100
Tetracyclines 2 names brands
Warnings, and notes
* Doxycycline (Vibramycin), Minocycline (Minocin, Solodyn)
* Warnings: Children \<8, pregnancy and breastfeeding
* Photosensitivity severe skin reactions(SJS, DRESS, TEN)
* GI ulcers
* Minocycline: drug induced lupus erythematousus (DILE)
* Notes: IV PO 1:1
101
Tetracycline Drug Interactions:
* Antacids and other polyvalent cations (mg, aluminum, calcium, iron, zinc) MVM, sucralfate, bismuth subsalicylates and bile acid resins, can chelate and inhibit tetracyclines absorption. Separate doses (1-2 hours before or 4 hours). Dairy products should be avoided 1 hour before or 2 hours after.
* Doxycycline and minocycline can be taken with food to reduce Gi upset. Dairy products are less of a concern compared to tetracycline
* Lanthanun carbonate can reduce the concnetrations of tetracycline derivatives; take tetracyclines at least 2 hours before or after lanthanum
* TETRACYCLINE is a major substrate of 3A4 and a moderate inhibitor. Use caution with 3A4 inhibitors increase levels, inducers decrease levels.
* Tetracycline can enhance the effects of warfarin and neuromuscular blocking drugs.
102
Sulfonamides MOA and coverage
Inhibits Dihydrofolic acid formation from para-aminobenzoic acid, which interferes with bacterial folate synthesis
Trimethoprim: inhibits dihydrofolic acid reduction to tetrahydrofolate, resulting in the inhibition of the folic acid pathway.
* Coverage: Gram-positive staph (including MRSA and CA-MRSA)
* S. Pneumo and Group A Strep coverage is unreliable
* Gram negative activity is broad including Haemophilus, Proteus, E. Coli, Klebsiella, Shigella, Salmonella, and stenotrophomonas
* Coverage includes some opportunistic infections (Nocardia, Pneumocystic, Taxoplasmosis)
* Pseudomonas, enterococci, atypicals and anaerobes arent covered
103
Bactrim Tablet Strength
SS: 400/80
DS: 800/160
104
WHat is bactrim dosing based off of?
TMP
105
Safety information for Bactrim
* Contraindications
* Sulfa allergy, pregnancy (long term) breasfeeding, anemia due to folate deficiency, marked renal or hepatic disease, infants less than 2 months
* Warnings:
* Skin reactions: SJS/TEN, thrombotic thrombocytopenia purpura
* G6PD deficiency; do not use if known dificiency and DC if hemolysis occurs
* Embryofetal toxicity
* SEs:
* Photosensitiivity, increase K, hemolytic anemia, (identified with a positive coombs test), crystalluria (take with 8 oz of water),
* Monitor renal function, E+, CBC and folate
106
Bactrim drug interactions
* 2C8 and 2C9 inhibitor can significantly increase INR
* Caution when used with warfarin
* Bactrim effects can be reduced by leucovorin and levoleuoco
* Hyperkalemic risk increases with ACEs, ARBS, aliskiren, aldosterone receptor antagonists, K sparing diuretics, NSAIDs, cyclosporine, tacrolimus, drosperinone containing products oral contraceptives, ot canagliflozin
107
Bactrim Notes:
* Commone uses
* CA-MRSA skin infections, UTIs, Pneumocytis pneumonia (PCP)
* 5:1 ration of SMX/TMP
* SS: 80 mg TMP
* DS 160 TMP usual dose is 1 tab BID
* Sulfa allergy
* Most common
* Rarely skin reactions will occur, SJS/TEN, can occur if rash is accompanied by fever or systemic symptoms go to ER
* INR increase when used with warfarin. Use another Abx if possible
