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96 Cards in this Set

  • Front
  • Back
Antimicrobials, Antiviral, and Antifungi Drugs
We'll first start with general background on Antimicrobial drugs. (Ex: therapy, misuses, mode of action, delaying emergence, dosage, and host factors).
__% of hospitalized patients receive drugs for infectious diseases. Chemotherapy, antibiotics, and antimicrobial agents are given.
30%
What is the difference between a narrow spectrum antibiotics and a broad spectrum antibiotic?
Narrow spectrum antibiotics work on only a few species of microbes whereas Broad spectrum work on a large number of species.
These drugs, other then chemotherapy, are able to target only bad organisms w/out harming cells or the host.
It's based on the cell differences in microbes and host cells.
There are quite a few ways for these drugs to eliminate or restrain the microbes (Mode of action). What are 6 MOA's and give an example of a drug for each.
You can do it!
1.) INHIBITION OF BACTERIAL CELL WALL SYNTHESIS OF ACTIVATION OF ENZYMES THAT DISRUPT THE CELL WALL
Include both broad and narrow spectrum antibacterial drugs that promote bacterial lysis & death (e.g. penicillins & cephalosporins)
2.) INHIBITION OF BACTERIAL PROTEIN SYNTHESIS
May be bactericidal (e.g. gentamicin) or bacteriostatic (e.g. tetracyclines)
3.) INHIBIT SYNTHESIS OF BACTERIAL DNA AND RNA
Binds directly to nucleic acids or interact with enzymes required for nucleic acid synthesis (e.g. ciprofloxacin)
4.) ANTIMETABOLITES
Interact with enzymes required for producing essential cellular metabolites (e.g. trimethoprim)
5.) INHIBITORS OF VIRAL ENZYMES (antiviral drugs)
Inhibit enzymes necessary for viral replication or infection; includes protease inhibitors and nucleoside analogs (e.g. zidovudine & indinavir)
6.) INCREASE MEMBRANE PERMEABILITY (antifungal drugs)
Cause leakage of intracellular material (e.g. amphotericin B)
Microbe RESISTANCE!
Microbes can become resistant to drugs due to an alteration in active uptake of specific antibiotics, alterations in drug receptors, etc
Microbe resistance in terms of DNA are due to spontaneous mutation or conjugation.
Bacteria are worse then Cancer cells in terms of resistance b/c they are faster at reproduction and are sloppy at it!
There are a few ways to DELAY EMERGENCE of drug resistance.
Use these drugs only when needed.
Use narrow spectrum agents when can.
Reserve newer antibiotics when older drugs are dangerous or aren't effective.
What does suprainfection mean?
A new infection that appears during the course of treatment for a primary infection.
Immunocompromised patients require bacteri_____ drugs.
IS it cidal or static?
cidal
These drug can cross placenta and breast milk.
True of false?
True

Tetracyclines and fluoroquinolones contraindicated during pregnancy
Is it okay to stop taking these drugs if one feels better even before the date given by the physician?
No

The patient must take the drug as long as the physician said too. Must not be discontinued prematurely. Why is that?
MISUSES
Attempt to treat an untreatable infection like the common cold or sore throat
Fever come from an unknown organism
MISUSES
Improper dosage
Lack identification of organism
Omission of surgical drainage
Now that we've talked about general information on these drugs...
Let's talk that the drugs themselves!
Drugs that weaken Bacterial Cell wall

The Penicillins, Cephalosporins, and
Vancomycin.
Let's start with the Penicillins...
Penicillin G
Nafcillin
Amoxicillin
Carbenicillin
Penicillins
MOA: weaken cell wall which causes bacteria to take up excess water and causes it to BLOW UP! Well...Rupture.
Is this drug a cidal or static drug?
Cidal of course! This drug kills the bacteria!

Resistance to this drug: the drug never gets to it's target, the bacterial enzymes inactivate this drug.
Penicillins are not safe drugs.
True or false?
FALSE!
Penicillins are among our SAFEST drugs!
It is also the most common drug for people to be allergic too..
Penicillin G [Benzylpenicillin]
Penicillin G [Benzylpenicillin]
Narrow spectrum penicillinase sensitive
Beats up: Streptococcus sp. Gram positive. Causes tetanus, gangrene, anthrax, syphilis.
Nafcillin [Nallpen]
(Methicillin no longer used in US)
Nafcillin [Nallpen]
Narrow-spectrum penicillinase resistant
Staphylococcus aureus
Amoxicillin [Amoxil]
and ampicillin [Marcillin]
Amoxicillin [Amoxil]
Broad spectrum
H. influenzae, E. coli, N. Gonorrhoeae
Inactivated by beta lactamases, so not helpful for Staphylococcus
Carbenicillin [Geocillin]
Carbenicillin [Geocillin]
Extended spectrum
Same as broad-spectrum, plus UTIs Pseudomonas aeruginosa and others
Narrow spectrum penicillinase sensitive
Penicillin G comes in different forms Only K plus penicillin G is given IV. The rest are given IM
Use of penicillinase inhibitor andbroad/extened spec pen
e.g. Clavulanic acid and amoxicillin [Augmentin]
Side Effects and Toxicities
Penicillin
GI~ heartburn, diarrhea, stomatitis, discolored tongue
DDIs: Increased bleeding time of anticoagulants; Inactivate aminoglycosides if in same IV bag; Potentially decreased efficacy of oral contraceptives
Penicillin Allergy
For one, you DON'T give a pt a drug if they are allergic to it.
This drug can cause anaphylaxis which has S/S of laryngeal edema, bronchoconstriction, and severe hypotention.
Treat with Epiniphrine, respiratory support, and prevention
Cephalosporin
MOST WIDELY used group of antibiotics
Bactericidal, beta-lactam antibiotics
Usually given parenterally
Mechanism of Action
Cephalosporin
Altered PBPs ~ Mechanism of Action
Bind PBPs (same as penicillin)
Methicillin resistant staphylococcus resistant to most cephalosporins
Adverse effects Cephalosporin
Adverse effects Cephalosporin
Allergy (5 to 10% cross-rxn w/penicillins), bleeding (DDIs!), thrombophlebitis
Four generations of Cephalosporins
Each subsequent generation has greater...name 3
~activity against Gram negative bacteria
~resistance to beta lactamases
~ability to reach CSF
First generation ~
Cephalexin [Keflex]
Used for staphylococcus if mild penicillin allergy
Third generation ~
Cefotaxime [Calforan]
Meningitis and nosocomial infections resistant to others (restricted use)
Vancomycin [Vancocin]
Ready?
Action Vancomycin
Action Vancomycin
Inhibitor of cell wall synthesis (like pens & cephs, however, vancomycin has no beta lactam ring, PBP binding, or penicillin allergy)
Uses (Restricted) Vancomycin
Uses (Restricted) Vancomycin
Only for severe infections; Gram positive bacteria
Methicillin resistant Staphylococcus aureus (MRSA), life threatening infection w/known susceptible organism in pt w/ severe allergy to penicillin, and Clostridium difficile colitis
Adverse effects Vancomycin
Adverse effects Vancomycin
Ototoxicity (give over 60 min to limit)
Allergic Rxn red neck syndrome ~ flushing, pruritus, tachycardia, hypotension
Avoid by infusing slowly, lowers histamine release
Thrombophlebitis
Bacteriostatic Inhibitors of Protein
You will know these 3 drugs...
Tetracyclines
Erythromycin
Linezolid
Tetracycline
Broad or Narrow Spectrum antibiotic?
Broad Spectrum antibiotic
Mechanism of Action Tetracycline
Mechanism of Action:
Inhibits protein synthesis by binding to 30S ribosome, thus inhibiting mRNA/tRNA activity
Bacteriostatic!!
Bacterial Resistance Tetracycline
Bacterial Resistance Tetracycline
Reduced drug accumulation
increased drug inactivation
decreased access to ribosomes
Clinical Uses Tetracycline
Clinical Uses Tetracycline
2nd line agent for resistant infections
Tetracycline 1st line Tx in
1st line Tx in:
Rickettsial disease, Chlamydia trachomatis, Cholera, Mycoplasma pneumoniae, Lyme disease, Anthrax, Helicobacter pylori
Acne
PUD
Tetracyclines~Adverse Effects
There are quite a few but know the MAIN ONE which has to do with teeth...
Adverse Effects:
Absorption~chelation
Do NOT administer with anything with Ca, magnesium~containing laxatives, and most antacids
Tetracycline Adverse Effects:
Effect on bone and teeth (Ca2+ binding) ~ can suppress long bone growth in premature infants (is reversible)
Avoid during pregnancy (Category D) & breastfeeding and in children <8 yo
Photosensitivity
Gastrointestinal (Admin w/ food)
Tetracycline Adverse Effects:
Superinfection ~ C. difficile colitis
Hepatotoxicity & Renal toxicity
Decreased oral contraceptive efficacy & breakthrough bleeding
Inhibitors of Protein Synthesis: Macrolides ~
Erythromycin [Erythrocin]
Mechanism of Action Erythromycin
Inhibits bacterial protein synthesis (binds to 50S ribosome)
Resistance Erythromycin
Develops from increased drug efflux and modification of ribosome
Erythromycin Commonly used if...
pt has severe penicillin allergy
ErythromycinGenerally few SEs...
GI (pain, nausea & vomiting, diarrhea)

DDIs! Avoid CYP3A4 inhibitors & antidysrhythmics due to cardiotoxicity
ErythromycinAntimicrobial spectrum
Broad spectrum similar to penicillin;
Erythromycin Uses
Uses:
First choice for several infections (pneumonia caused by Legionella pneumophila, Bordetella pertussis, Corynebacterium diphtheriae)
Bacteriostatic Inhibitors of Protein Synthesis. Whats the 3rd one!?
Linezolid [Zyvox]
Has activity against VRE and MRSA. What do they stand for?
multidrug resistant gram positive pathogens~ vancomycin resistant enterococci (VRE) and methicillin resistant Staphylococcus aureus (MRSA)
Aminoglycosides: Bactericidal Inhibitors of Protein Synthesis. The 3 drugs prior to this one were bacterioSTATIC...
You'll just be learning one....which one is that now?
Gentamycin [Garamycin]
Gentamycin MoA
Gentamycin MoA:
Severely disrupts bacterial protein synthesis (inhibition, AA termination, misreading)
GentamycinUse:
GentamycinUse:
Serious infections caused by aerobic Gram negative bacilli (narrow spectrum)
Gentamycin Adverse effects
Gentamycin Adverse effects:
Sig injury to inner ear and kidney (note high pitched tinnitus & headache)
Neuromuscular blockade (respiratory depression)
DDIs~(eg inactivated if in IV bag w/ Pen)
Gentamycin
Must be given parenterally b/c not absorbed
True or False?
True!
Sulfamethoxazole
What are the two drugs you should know?
Sulfonamides and Trimethoprim
Suppresses bacterial growth by:
Suppresses bacterial growth by inhibiting the synthesis of a DNA & RNA precursor (folic acid, aka folate)
Sulfonamides and Trimethoprim Uses
Uses
**Uncomplicated urinary tract infection (Escherichia coli)
Pneumocystis carinii (common in immunocompromised hosts)
Sulfonamides and Trimethoprim Adverse effects
Adverse effects:
Hypersensitivity reactions
***SEVERE is Stevens Johnson syndrome (low incidence, but 25% mortality)
In peds and young adults; Major skin & mucous lesions, fever, malaise, toxemia
Adverse effects cont:

***Kernicterus (deposits of billirubin in brain)
This drug is contradicted for who?
Contraindicated for infants under 2 mo; during pregnancy (Category C) & breastfeeding
Fluoroquinolones
What is the prototype?
Ciprofloxacin [Cipro]
Ciprofloxacin [Cipro]
Broad spectrum antibiotic
Inhibits bacterial DNA gyrase (bactericidal)
Used for:
Most significant
UTI and Anthrax
Adverse effects:
Most significant
CNS and tendon rupture
Candida of pharynx and vagina
Drug and food interactions
Ciprofloxacin [Cipro]
Foods w/ cations (e.g. Ca2, Al, Mg2) will decrease drug absorption
Take on an empty stomach
So, those were all of you antimicrobials!...
Let's review. What are the prototypes for the mode of actions?
Inhibition of bacterial cell wall synthesis
penicillins & cephalosporins
Inhibition of bacterial protein synthesis
bactericidal (e.g. gentamicin) or bacteriostatic (e.g. tetracyclines)
Inhibit synthesis of bacterial DNA and RNA
(e.g. ciprofloxacin)
Antimetabolites
(e.g. trimethoprim)
We have Antiviral and Antifungi drugs left. For Antiviral drugs, you will be learning about...
Antiviral:
Acyclovir
Zidovudine [Retrovir] (AZT)
Nevirapine [Viramune]
Indinavir [Crixivan]
Drug for Non HIV Viral Infections
Acyclovir [Zovirax]
Purine nucleoside analogs
Acyclovir Uses
Herpes simplex viruses
Varicella zoster virus
Adverse effects based on route of administration
IV ~ phlebitis and reversible nephrotoxicity
Oral therapy ~ GI and vertigo
Topical ~ stinging sensations
Antiviral Agents II: Drugs for HIV Infection & Related Opportunistic Infections
antiretroviral drugs
HIV fusion inhibitors
Reverse transcriptase inhibitors:
Nucleoside~ Zidovudine
Nonnucleoside ~ Nevirapine
Protease inhibitors: Indinavir
Nucleoside Reverse Transcriptase Inhibitors (NRTIs)
Zidovudine [Retrovir]

Inhibits HIV replication
Zidovudine Adverse effects
Adverse effects:
Anemia
Neutropenia
Lactic acidosis
Gastrointestinal effects
CNS
Non Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)
Nevirapine [Viramune]
Binds to HIV reverse transcriptase
Nevirapine Adverse effects
Adverse effects
Rash
Erythema multiforme
Stevens Johnson syndrome
Hepatotoxicity
Drug interactions
Protease Inhibitors
Indinavir [Crixivan]
Adverse Effects Indinavir
There QUITE a few. Ask Dr. Murphy if there are any that you NEED to know.
Hyperglycemia/diabetes
Fat redistribution
Hyperlipidemia
Reduced bone density
Hepatotoxicity
Increased bleeding in hemophiliacs
Reduced bone mineral density
Elevation of serum transaminase
Drug interactions
That is the end of antiviral drugs!
On to Antifungal agents!! What are the 4 drugs you will be learning?
Amphotericin B [Fungizone]
Ketoconazole [Nizoral]
Miconazole [Monistat]
Nystatin [Mycostatin]
There are 2 major groups of antifungal drugs...
Systemic mycotic infections
Superficial mycotic infections
Systemic mycotic infections
Systemic mycotic infections
Opportunistic~candidiasis, aspergillosis, cryptococcosis, mucormycosis
Nonopportunistic sporotrichosis, blastomycosis, histoplasmosis, coccidioidomycosis
Superficial mycotic infections
Superficial mycotic infections
Candidiasis
Dermatophytes
Amphotericin B [Fungizone]
Broad spectrum antifungal, agent of choice
Highly toxic
MoA Amphotericin B
MoA
Damages fungal cell membrane causing leakage of intracellular K
Uses: Amphotericin B
Uses: systemic mycoses
Limit use to progressive and potentially fatal infections
Adverse effects Amphotericin B
Adverse effects Amphotericin B
Infusion reactions
Nephrotoxicity
Hypokalemia
Ketoconazole [Nizoral]
Fungistatic
Alternative to amphotecirin B for systemic mycoses
Adverse effects Ketoconazole
Most Significant ones!
Hepatotoxicity
Effect on sex hormones
Miconazole [Monistat]
Use~
vaginitis
Creams and vaginal inserts
Nystatin [Mycostatin]
Use ~
thrush (candidiasis)
If treating nursing baby, then treat mother (and vice versa)