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When are anti-infectives given prophylactically?
- HIV
- Immunocompromised
- Pre-op
- Endocarditis (recently not recommended)
The treatment for CMV is a drug that is toxic to the bone marrow. How do you know if someone has the virus even before they are symptomatic? What is the drug?
You can test for CMV DNA. The patient will have DNA in the serum even before they are symptomatic. Then you can treat with Gancyclovir only to those that really need it.
What are most antibiotics used for?
To give to livestock so that they grow bigger!
What is the mechanism of action of sulfonamides?
Blocks the use of PABA in tetrahydrofolate synthesis
Who discovered penicillin?
Alexander Fleming in 1928
How is the theraputic index of a drug calculated?
Minimum toxic concentration / Minimum effective concentration
Syphilis: DOC
Penicillin
Why is polymyxin no longer used?
Because of nephrotoxicity
What is the cause of vancomycin "redman syndrome"?
Giving vanco too fast causes release of histamine. Not a true allergic reaction.
Penicillin: effective against what type of bacteria?
gram +
Penicillin: distribution to most areas of the body? Distribution to eye, brain, CSF, prostatic fluid?
Distribution to most areas = good.

Distribution to eye, brain, CSF, prostatic fluid = not good
What does the ending, "mycin" indicate?
That the antibiotic was isolated from the Streptomyces bacteria.
Why isn't gentamicin spelled with a y?
Because it was not isolated from Streptomyces. It was isolated from Micromonospora purpureae.
What is MIC?
Mimial Inhibitory Concentration. The least amount of ABX that can kill bacteria.
Enterococcal endocarditis: ABX
Penicillin + Gentamicin
CNS penetration: metronidazole, fluconazole
Excellent
CNS penetration: Ceftriaxone, ampicillin
Adequate with high doses
CNS penetration: Vancomycin, aminoglycosides
Not good. Sometimes have to give aminoglycosides intrathecally.
1st line for meningitis
Ceftriaxone
What is a drug that is 0% effective in treating lung infections?
Daptomycin - it's inactivated by surfactant.
Good for treating lung infections
Quinolones, macrolides, beta-lactams
What is the difference between MIC and MBC?
MIC = Minimal Inhibitory Concentration

MBC = Minimal Bacteriocidal Concentration
What is a drug that is cidal for listeria but is normally bacteriostatic?
TMP/SULFA

(Note that another drug for listeria is ampicillin)
Penicillin: static or cidal?
Usually cidal.
When is it recommended to use a combination of penicillin and an aminoglycoside?
Enterococcal endocarditis.

Enterococci are tolerant to penicillins and resistant to gentamicin. But together they are effective. This is because the penicillin punches holes in the membrane, allowing gentamicin to get into the bacteria.
What is an example of an antimicrobial combination that produces antagonism?
Tetracycline and penicillin. Tetracycline blocks protein synthesis, blocking the cell growth that penicillin needs to cause lysis. The result is a bacteriostatic effect.

A study done in 1951 showed a sharp rise in meningitis with administration of tetracycline + penicillin. (But small sample size)
Three different examples of antimicrobial combinations that cause synergistic effect:
1. Penicillin + gentamicin

2. Trimethoprim + sulfamethoxazole

3. Clavulanate (inhibitor of β-lactamase) + amoxicillin
Penicillins and enterococci: cidal or static?
Penicillins are usually cidal, but they are static with enterococci.
Listeria meningitis: DOC?
Most recommend ampicillin (with or without an aminoglycoside) as the first choice.
When might the use of a bacteriocidal agent be harmful?
When a disease is associated with the release of a toxin (Staph or E. coli)
CNS infections, endocarditis: use cidal or static ABX?
Cidal
Define and give an example of an ABX that exhibits concentration-dependent killing
The higher the concentration, the greater the activity - aminoglycosides, quinolones.
Define and give an example of an ABX that exhibits time-dependent killing.
The extent of killing depends on the time of exposure - β-lactams, vancomycin.
Time-dependent killing ABX should be dosed on the basis of what marker?
Based on the "time above MIC"

Need frequent dosing.
Concentration-dependent killing ABX should be dosed on the basis of what marker?
Based on the area under the curve.
What are three different infections that require long courses of ABX?
1. Endocarditis: 28-42 days
2. Osteomyelitis: 42 days
3. Prostatitis: ?
Group A strep: DOC?
Penicillin: 4x day for 10 days, but no GAS is resistant.

Amoxicillin: Don't have to take as often

If penicillin resistant, take erythromycin or other macrolide (azithromycin)
Group A strep: what drug is not recommended?
Cephalosporins (even though GAS is sensitive) ??
Erythromycin: AE?
GI distress
Gram negative bacteria and location of β-lactamase?
Secreted inside the bacterial cell wall, thus it can be overcome with increased doses of ABX
Penicillin G: DOC for what?
1. Gram + cocci
2. GAS
3. GBS
4. Spirochetes
5. S. pneumo (now some resistant)
How do β-lactams work?
They bind and inactivate the Penicillin Binding Proteins (PBP) that catalyze the joining of peptides in the cell wall.

The β-lactam "mimics the peptide bond"
What are three β-lactamase inhibitors, and what are the drugs that they are paired with?
1. Clavulanic acid + amoxicillin = Augmentin (PO)

2. Sulbactam + Ampicillin = Unasyn (IV)

3. Tazobactam + Piperacillin = Zosyn
β-lactamases in gram - bacteria are secreted into what space?
Into the periplasm
c/c Amoxicillin, Ampicillin with Penicillin
Amoxicillin and ampicillin have extended spectrum and are effective against gram negatives like: H. flu, E. coli, Proteus mirabilis.
c/c Amoxicillin with a β-lactamase inhibitor and without
With β-lactamase inhibitor gives activity to Staph and other gram negatives.
Unasyn: uses?
Animal bites
Interabdominal wounds
Unasyn: noted for activity against what bacteria?
Bacterioides fragilis.
How does staph become resistant to methicillin?
By altering the penicillin binding proteins from PBP2 to PBP2a (which has a low affinity for β-lactams).

Also by altering the fem genes.
What are the three main anti-staph penicillins?

What are they not effective against?
1. Methicillin
2. Nafcillin
3. Oxacillin

All are resistant to S. aureus β-lactamase, but NOT gram negative β-lactamases!

Also note that these are not effective against MRSA!
Enterococci: mechanism of resistance to cephalosporins?
Pump the drug out. Also seen with pseudomonas resistant to piperacillin.
Pseudomonas: DOC?
Piperacillin
Piperacillin: characteristic features
- Has activity against Pseudomonas and other gram negatives.

- When paired with tazobactam (Pip/Tazo or Zosyn), is effective against Pseudomonas and anaerobes
c/c ampicillin and piperacillin
Ampicillin has activity against some gram negatives, but only piperacillin has activity against pseudomonas.
Pip/Tazo: spectrum
HUGE
c/c rings of penicillin and cephalosporins
Penicillins = 5 membered ring
Cephalosporins = 6 membered ring
Cephalosporins: mechanism of action?
Bind to PBP to prevent cross-linking, preventing formation of peptidoglycan.
c/c penicillin and cephalosporins: susceptibility to β-lactamases
Cephalosporins are more resistant to β-lactamases than penicillins
Notable about 1st generation cephalosporins
They do not penetrate into the CNS
As the generation number of cephalosporins increases, what also increases?
The broadness of the spectrum
Example of a 1st generation cephalosporin
Cefazolin
No cephalosporin will treat what bugs?
Enterococcus
Listeria
Pseudomonas
What is a good rule about remembering the spectrum of cephalosporins?
That they cover everything that penicillins do plus...

Cefazolin: GAS, non-fragilis anaerobes, S. aureus, E. coli.
Cefazolin: DOC for what?
Cellulitis
Cefazolin: effective against what?
Cefazolin: GAS, non-fragilis anaerobes, S. aureus, E. coli
Cefuroxime: notable for effectiveness against what?
H. flu and extended gram - spectrum
Cephamycins (Cefoxitin and Cefotetan): notable for effectiveness against what?
B. fragilis and Serratia
What is the main problem with 2nd generation cephalosporins?
They induce chromosomal β-lactamases.

Thus never use a 2nd gen ceph with a β-lactam ABX
3rd generation cephalosporins: notable for effectiveness against what?
Greatly expanded gram - spectrum (including citrobacter, serratia marcescens)

Also longer half-lives

Cross the BBB well
Drugs that are effective against pseudomonas?
2nd or 3rd gen ceph
Extended spectrum penicillin
2nd/3rd gen ceph: not effective against?
Listeria (need to add ampicillin to the regimen)
Bacterial meningitis: DOC?
3rd gen ceph
Two examples of 3rd gen ceph?
1. Ceftriaxone
2. Cefotaxime
What is the half-life of penicillin?
30 minutes.
Two carbapenems.
Imipenem
Ertapenem
Carbapenems: notable for?
Very broad spectrum. Effective against gram +, enterococci, and resistant gram - species.

Highly resistant to β-lactamases
Example of a monobactam
Aztreonam - only has gram - activity
Why are β-lactam drugs effective against rapidly dividing bacteria?
Because they inhibit the growth of the cell wall
Febrile, neutropenic patients that are allergic to penicillin: DOC?
Aztreonam. Broad gram - activity. Often given with vancomycin because of absence of gram + activity.
What is imipenem often administered with and why?
Cilastatin, because imipenem can be hydrolyzed by dehydropeptidase in the mammilian kidney.

Cilastatin is a dehydropeptidase inhibitor.
Extended Spectrum β-lactamases are often found in what bacteria?
In the family enterobacteriaceae
Extended Spectrum β-lactamases are effective at inactivating what ABX?
Cefotaxime
Ceftriaxone
Ceftazidime
Aztreonam ???
Allergies to β-lactam ABX occur in up to what percentage of patients?
10%
What percentage of patients have IgE-mediated reactions to β-lactams?
0.01%
What is a good estimate of the cross-reactivity between penicillins and cephalosporins?
about 0.5%.

Thus 2nd/3rd gen cephs are unlikely to cause a reaction in those with penicillin allergies.
Most rashes and other reactions to β-lactams are what?
Are not immunologically mediated.
What do people with mono caused by EBV often get treated with? What does this cause in 100% of patients?
Amoxicillin. Patients with EBV mono that are treated with amoxicillin will develop a maculo-papular rash.

This does NOT mean that the patient is allergic to amoxicillin. The patient can be treated again in the future.
What percentage of patients with anaphylaxis to penicillin will have a reaction when re-challenged?
about 50%
Patient with an anaphylactic reaction to penicillin: don't give what?
A 1st generation ceph like Cefazolin.
In particular, you should not re-challenge a patient if he or she has had what two reactions?
Steven-Johnson syndrome
Toxic Epidermal Necrolysis

Seen mainly with sulfa drugs

(both basically skin sloughing)
"last line" against MRSA
Vancomycin
Vancomycin: effective against?
Gram +, particularly MRSA
c/c speed of action of penicillin and vancomycin
penicillin is faster-acting that vancomycin
Vancomycin: mechanism of action
Binding to the D-Ala-D-Ala terminus of nascent peptidoglycan assembly
Vancomycin: major toxicity
Red man syndrome due to histamine release.
Vancomycin + gentamicin: used for?
For enterococci like E. faecium and E. faecalis.

Also the drug of choice for treatment of enterococcal endocarditis in a patient with penicillin allergies.
VISA: definition?
Vancomycin Insensitive Staph Aureus.
What is the DOC for Staph non-aureus?
Vancomycin
c/c cellulitis and arthritis: redness around a joint
If arthritis, will be painful to move joint.
Macrolides:
Examples
Mechanism of action
Mechanism of excretion
Targets
Examples:
Erythromycin, azithromycin, clarithromycin

M of A:
Inhibit protein synthesis (50S), bacteriostatic

M of E:
Bile and minially in urine

Targets:
Gram +, but not MRSA
Some gram -
Atypicals
Some anaerobes
Aminoglycosides:
Examples
Mechanism of action
Mechanism of excretion
Targets
Examples:
GNATS: Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin

M of A:
Inhibit protein synthesis (30S), bactericidal

M of E:
Excreted unchanged in urine

Targets:
Staph (combine with β-lactams)
Gram -
Tetracyclines:
Examples
Mechanism of action
Mechanism of excretion
Targets
Examples:
Tetracycline, doxycycline

M of A:
Inhibit protein synthesis (30S)

M of E:
Excreted mostly in the urine

Targets:
Some gram +
Some gram -
Atypicals
Clindamycin/lincosamides: effective against which bugs?
S. aureus
S. pyogenes
Anaerobes above the diaphragm
Clindamycin/lincosamides: Attractive for what general type of bugs in what type of patients?
Attractive for gram + infections in patients with penicillin allergies.
Clindamycin/lincosamides: Active agains what type of resistant bacteria?
Active against penicillin-resistant S. pneumoniae.
Clindamycin/lincosamides: Toxicity?
C. difficile.
Clindamycin/lincosamides: Used for endocarditis?
No - this is a static drug, don't want to use.
Clindamycin/lincosamides: cidal or static?
Static
Clindamycin/lincosamides: Topical treatment used for?
Acne.
c/c tetracycline and doxycycline: secretions
Both get into secretions well, but tetra goes into the urine, while doxy does not.
Rickettsial diseases: DOC?
Doxycycline
Mycoplasma pneumoniae: DOC?
Tetracyclines
Chlamydia pneumoniae
Tetracyclines
Lyme disease
Tetracyclines
Brucellosis
Tetracyclines
Tetracyclines are alternative agents for what two diseases?
Plauge
Pelvic inflammatory Disease
c/c tetracycline and doxycycline: anti-parasitic activity
Doxycycline has anti-malarial effects.
1st generation quinolones: example, attributes
Nalidixic acid (NegGam, Wintomylon)

Active against gram - only, rapid resistance is a problem
2nd generation quinolones: example, attributes
Ciprofloxacin (Ciprobay, Cipro, Ciproxin)

Covers a broader spectrum of gram negatives, including Pseudomonas.

Often used for traveller's diarrhea. Not good against gram + or S. pneumo (thus not acceptable drug for community acquired pneumonia)
3rd generation quinolones: example, attributes
Levofloxacin (Cravit, Levaquin)

Activity against gram +, once a day dosing. Also activity against gram - aerobes.
Doxycycline: spectrum, uses?
Broad spectrum against gram + and gram - aerobes.

Affects S. pneumoniae and H. influenzae, thus can be used to treat community aquired pneumonia.
Doxy: can't be given to children or pregnant women because?
Stains developing teeth
Incorporates into bones
Doxy: when given PO, can't be given with what two substances?
Metal or milk
Doxy: primary use?
Against "atypical organisms" like Rickettsiae, Mycoplasma, Chlamydia.
Tigecycline:

Family of drugs
Spectrum
Effective against what bugs?
Mechanism of elimination?
Main uses?
A gylcylcycline

Very broad spectrum with activity against vanc resistant streph and staph. Broad aerobic and anaerobic spectrum.

Eliminated in the biliary system (no need to adjust for renal failure)

Main uses are for MRSA and cellulitis
Teracyclines: adverse effects
Most common: vomiting and nausea.

Tetra binds Ca and incorporates into bone and teeth.

Photophobia, sensitivity to light

Prolonged use can cause yeast infections due to broad spectrum actions against anaerobes.

Dose carefully in patients with hepatic failure.
UTI: DOC?
Tetracycline (and not doxycyline)
Treatment of M. avium, M. leprae
Clarithromycin
c/c Erythromycin and Clarithromycin: side effects
Erythromycin can cause severe GI distress ("Erythromycin belly"), while Clarithromycin is fairly well tolerated.
What drugs are thought of as "good intracellular drugs"
Macrolides. Thus they have activity against Legionella, Mycoplasma.
Chlamydia: DOC?
Azithromycin
Erythromycin: activity against which bugs?
Gram + cocci, B. pertussis, Legionella, Mycoplasma.
Mycoplasma pneumoniae: DOC?
Macrolides (azithromycin)
Legionella pneumoniae: DOC?
Macrolides (azithromycin)
Macrolides are alternative agents for what two diseases?
Lyme disease, Chlamydia infection.
Azithromycin: unique properties
Has almost no serum level, but has a high tissue level.

Has a half-life of 2-4 days
c/c Doxy vs. Azith for Chlamydial cervicitis/urethritis
A single dose of azith is equal to a 7 day course of doxy
Usual course of treatment with azith with patients with community acquire pneumonia?
A 5 day course.
Clindamycin: attributes
Often prescribed for bone and joint infections.

Active against Staph, Strep, anaerobes (including B. fragilis)

Binds to the 50S subunit

Can be given IV or PO

Can cause C. diff enterocolitis
Chloramphenicol: attributes
Binds to the 50S subunit

Broad spectrum:
static for gram -
cidal for S. pneumo, H. flu

Second-line for Rickettsial

Has bone marrow suppressive effect.

AE: in 1/20-40,000 cases can cause aplastic anemia - permanent bone marrow damage.
Sulfonamides: structural analogues of what compound?
PABA, para-aminobenzoic acid
Sulfa: why does it work?
While mammals must take up folate from the environment, bacteria must synthesize it from PABA.

Sulfonamide competes with PABA.
Trimethoprim: Mechanim of action?
Inhibits dihydrofolate reductase
What is the synthetic pathway of Tetrahydrofolic acid?
para-aminobenzoic acid ---------dihydropteroate synthase --------> Dihydrofolic acid --------- dihydrofolate reductase --------> Tetrahydrofolic acid --------> Purines -------> DNA
c/c TMP or Sulfa vs TMP/Sulfa
TMP or Sulfa are static
TMP/Sulfa is cidal
SMX/TMP: increasing resistance seen with what bug?
S. pneumo
SMX/TMP: limited use in what type of infections?
Respiratory infections
SMX/TMP: excellent for what type of infections?
UTIs (esp E. coli), and some bacterial diarrheas.

No longer used for otitis media
Prophylaxis against Pneumocystis jirovecii and Toxoplasma gondii: DOC?
TMP/SULFA
TMP/SULFA: spectrum? No activity against? (2)
Broad spectrum with activity against gram + and gram - aerobes.

No activity against anaerobes!
No activity against pseudomonas!

Variable activity against S. aureus.
Nocarida infection: DOC?
TMP/SULFA
Aminoglycosides: cidal or static?
cidal
Aminoglycosides: Mechanism of action?
Inhibits the 30S ribosomal subunit.
Aminoglycosides: Spectrum?
Predominantly gram - aerobes

No anaerobic spectrum!
Aminoglycosides: Most commonly used drug?
Genatmicin
Streptomycin: uses? Side effects?
Used as 2nd line for TB, but is ototoxic
Amikacin: What type of drug? Uses?
Aminoglycoside, used for non-TB mycobacteria (M. fortuitum)
Aminoglycosides: dosing
Dosed daily because they are concentration-dependent drugs.
Aminoglycosides: What are common toxicities and what can be done to reduce them?
Nephrotoxicity, ototoxicity, vestibular toxicity.

Incidence can be reduced by avoiding high sustained (trough) levels of the drug.
Staph not-aureus: use what drug combo?
Vanc + gentimicin
Metronidazole: attributes
Prodrug - requires activation of active nitro group.

Only ANAEROBIC bugs can activate metronidazole!

Thus activity is limited to anaerobes and protozoans

Especially useful for B. fragilis and C. difficile

Adverse "antabuse" reaction to alcohol

Used to treat giardia and amebiasis.
Metronidazole: major toxicity?
"Antabuse" reaction to alcohol - flushing, dizziness.

Metallic taste
Giardia and amebiasis: DOC?
Metronidazole.
Oxazolidinones, (e.g. Zyvox): good for?
Good for resistant gram + strains like VRE.
Streptogramins: two examples?
Dalfopristin
Quinupristin
Quinolones: static or cidal?
Cidal
Quinolones: concentration or time dependent?
Concentration
Quinolones: Mechanism of action?
DNA gyrase inhibitors
Quinolones: most commonly used drug?
Levofloxacin
Levofloxacin: what type of drug? Activity against what?
3rd generation quinolone. Activity against gram + and gram - aerobes.

No anaerobic activity!
Levofloxacin: why is it good for neutropenic patients?
Because it destroys likely culprits aerobic gram - and gram + organisms, but does not disrupt normal colonic flora (mostly anaerobes)
Levofloxacin: Mechanism of excretion?
Renally. So has good urine penetration.
Ciprofloxacin: what type of drug?
2nd generation quinolone.
Rifampin: attributes
Broad spectrum

Works by inhibiting DNA polymerase

Causes orange urine and can cause liver disease.

Induces P450 enzymes, increasing the elimination of warfarin, protease inhibitors.

Infrequent dosing can lead to flu-like symptoms upon withdrawl and rarely acute tubular necrosis.

Use limited by rapid development of resistance

Major drug for TB

Penetrates tissues - used to eliminate carrier state.
What are the three prinicpal classes of antifungals?
Polyenes
Azoles
Pyrimidines
Amphotericin B:
Broad spectrum
Activity against Candida, Aspergillus, Mucor, Cryptococcus

IV only

Administration leads to fever, chills, rigors
c/c azoles/echinocandins and amphotericin B: effectiveness against Mucor
Amphotericin B is effective against Mucor, azoles and echinocandins are not.
Fluconazole: attributes, active/not active against?
Well absorbed
Well distributed in tissues
Not toxic
Available PO and IV
Long t1/2

Active against:
Most Candida (but not C. krusei or C. glabrata)
Coccidioides immitus
Cyptococcus

Not active against Aspergillus

Main problem: drug/drug interactions
Fluconazole: major problem with use.
Drug/drug interactions due to inhibition of P450 enzymes.

Fluconazole increases plasma concentrations of cyclosporin, tacrolimus, phenytoin, and sulfonylureas.
Itraconazole: DOC for?
Histoplasmosis, Blastomycosis, Sporotrichosis
Itraconazole: problems with use (4)
Can cause hepatotoxicity

Poorly absorbed orally

Inibits P450 enzymes and affects the metabolism of drugs like warfarin, statins, oral contraceptives.

Itraconazole levels are also reduced by many drugs like rifampin, INH, PPIs, H2-receptor blockers.
Which anti-fungal azole has the broadest spectrum?
Posaconazole.
Azole that has both IV and PO routes
Voriconazole
What anti-fungal is more effective than amphotericin B at fighting Aspergillus?
Voriconazole
c/c Posaconazole and Voriconazole: activity against Mucor
Posaconazole has better activity against Mucor
Aspergillosis: DOC?
Variconazole
Variconazole metabolism is accelerated by what drug?
Rifampin
Variconazole: adverse effects
Liver function abnormalities, prolonged QT interval.

Transient visual disturbances with IV administration.
What drug do you use if Candida becomes resistant to azoles?
Caspofungin
c/c Caspofungin and Micafungin/Anidulafungin: P450 interactions
Micafungin/Anidulafungin do not have P450 interactions
Caspofungin: limits to use?
IV only
Echinocandins: Mechanism of Action?
Block β-(1,3)-glucan synthesis
Echinocandins: limitations
No activity against Cryptococci, Fusarium, Zygomycetes
What are three different types of Echinocandins?
Caspofungin
Anidulafungin
Micafungin
Echinocandins: effective against?
Broad spectrum, including azole resistant species.

Fungistatic for Aspergillus
What drugs are not effective against Pneumocystis jiroveci? Why?
Amphotericin and the Azoles are not effective because P. jiroveci lacks ergosterol.
Pneumocystis jiroveci: DOC?
TMP/SULFA
Why do you need to give multiple ABX to treat TB?
Because the mutation rate is so high.
Isoniazid: Mechanism of Action?
Inhibits the synthesis of mycolic acid
Ethambutol: Mechanism of Action?
Inhibits mycobacterial arabinosyl transferases, blocking cell wall formation.
Pyrazinamide: Mechanism of Action?
Penetrates cell wall, M of A not well defined.
Isoniazid: toxicity
Heptatoxic

INH = Injures Neurons and Hepatocytes
Leprosy: DOC?
Some combo of Dapsone + Rifampin + Clofazimine for 6-12 months.
Acyclovir: activity against what?
HSV-1, HSV-2, VZV

In vitro activity against: CMV, EBV, HHV-6
Acyclovir: M of A?
Acyclovir is a nucleoside analogue that is phosphorylated by viral thymidine kinase. It then inhibits viral DNA polymerase and causes chain termination.
Ganciclovir: used for?
More extended spectrum than acyclovir. Used for CMV treatment and prophylaxis. IV and retinal implant.

Valganciclovir is the PO form.
c/c acyclovir and ganciclovir: toxicity
Ganciclovir is much more toxic. Bone marrow suppression and neutropenia
Cidofovir: attributes?
Used for resistant CMV and other Herpes viruses.

IV only - weekly dose

Nephrotoxic
For years, what has been the standard treatment for Hep B and C?
Interferon alpha
What does the addition of polyethylene glycol (PEG) do to interferon alpha?
It enhances the serum half life
IFN-α: toxicities?
Fever, myalgias, chills

Also neurologic and auto-immune issues.

Many contraindications, especially hepatic issues, auto-immune, arrhythmias, psychosis, etc.
IFN-α: downsides to use
Toxicities and that it is administered IM
Hepatitis B: DOC?
IFN-α, some reverse transcriptase inhibitors and DNA polymerase inhibitors also being used.
Hepatitis C: DOC?
PEG modified IFN + PO ribavirin
Ribavirin: what is it?
A guanosine analog
Ribavirin: especially effective against what disease?
Lassa fever
Ribavirin: toxicity
IV form: 10 - 20% of patients have hemolytic anemia.

PO toxicities not as well defined.
Lamivudine: M of A?
Inhibits HBV DNA polymerase.
Lamivudine: Major limitation?
Development of resistance
Lamivudine: used for what disease?
HBV
Adefovir Dipivoxil, Entecavir, Telbivudine: drugs for what disease?
HBV
Influenza A: what 4 drugs?
AROZ:

Amantadine
Rimantadine
Oseltamivir
Zanamivir
Influenza B: what 2 drugs?
Oseltamivir
Zanamivir
Amantadine and Rimantadine: M of A?
Bind to the M2 protein and inhibit uncoating.
Amantadine and Rimantadine: effectiveness?
Both only effective against influenza A.
Amantadine and Rimantadine: Most effective when given for what?
When given for prophylaxis.
Amantadine and Rimantadine: toxicities?
GI (nausea, vomiting), CNS (nervousness, difficulty concentrating, insomnia, light-headedness) are common side effects.
c/c Amantadine and Rimantadine: which has more activity
Rimantadine
Amantadine and Rimantadine: dose reduction is necessary for what disease state?
Renal failure.
Neuroaminidase inhibitors: two examples.
Oseltamivir and Zanamivir
Oseltamivir and Zanamivir: what are they?
Neuraminidase inhibitors/Sialic acid analogs
Falciparum malariae: DOC?
Chloroquinone and mefloquine
Hepatic phases of malaria and eradication of vivax/ovale: DOC?
Primaquine
What is artemisinin made from?
From wormwood.
In order to prevent recrudescene, combo therapy is often used when using this drug for malaria.
Artemisinin combination treatment (ACT)
Primaquine: contraindication?
G6PD deficiency
What are some drugs that are used to prophylactically prevent malaria?
Chloroquine
Malarone
Mefloquine
Doxycycline
Primaquine
Giardia: DOC?
Metronidazole, single 2 gram dose
Amebiasis: DOC?
Variesm but Metronidazole works.
Trichomoniasis: DOC?
Metronidazole, single 2 gram dose
What class of drug has improved the treatment of malaria?
Artemethers
What class of drug has improved the treatment of helminth infections?
Benzimidazoles
Benzimidazoles: M of A?
Thought to inhibit worm microtubule synthesis
Albendazole: activity against?
Ascaris, Trichuris, Cutaneous and Visceral larva migrans, Echinococcus.
Albendazole: administration?
PO
Albendazole: side effects? Prolonged therapy with steroids can cause what?
Usually none. Prolonged use can cause pancytopenia.
Mebendazole: Active against?
Ascaris, Trichuriasis, hookworm, pinworm
Mebendazole: side effects?
Unusual
Mebendazole: not for use in patients with what disease?
Liver cirrhosis.
Mebendazole + metronidazole = what adverse reaction?
Steven-Johnson Syndrome
Praziquantel: adverse effects?
Lots, but usually transient
Praziquantel: M of A?
Thought to increase membrane permeability fo Trematodes and Cestodes to calcium
Praziquantel: effective against?
Schistosomiasis, Taenia, Diphyllobothriasis, Clonorchiasis, Opisthorchiasis, Paragonimiasis
Praziquantel: DOC for what?
Schistosomiasis
Schistosomiasis: DOC?
Praziquantel
What class of drugs would you use with a ESBL bug?
Carbapenems (Imipenem, Ertapenem)
Drugs that need adjustment in patients with renal failure.
1. Aminoglycosides
2. Vancomycin
3. Beta-lactams
- except nafcillin, oxacillin
- except ceftriaxone, cefoperazone
- especially imipenem
4. Sulfa-containing agents
5. Fluoroquinolones
6. NOT minocycline, doxycyline (both cleared by the liver)
Drugs that need adjustment in patients with liver disease.
a) Penicillins - Nafcillin, Oxacillin and Piperacillin - half-life increased by about 25-50%increase dosing interval by 50%.
b) Clindamycin - t1/2 increased by 100%; double dosing interval.
c) Doxycycline, Minocycline - avoid in liver failure
What types of drugs should be decreased in the elderly because of overall decreased volume of distribution of water-soluble drugs?
Aminoglycosides, vancomycin
What drug do you use for GAS necrotizing fascitis?
Group A Streptococcus necrotizing fascitis - requires non-cell wall active agent (Clindamycin) because of high density of organisms, in non-dividing state.