Pharmacology II Flashcards
If an antibiotic has the ability to kill bacteria, it is _______.
If an antibiotic inhibits bacterial growth, it is ______.
Bactericidal
Bacteriostatic
Antibiotics that are effective against a small number of bacteria are _______.
What is an example of an antibiotic that is only effective against G+ and a few G- bacteria?
Narrow Spectrum
Penicillin
Antibiotics that are effective against many bacteria are ______.
What is the antibiotic with that kills the most variety?
Broad Spectrum
Tetracycline (kills G+ and G-, rickettsia, and some viruses)
What type of microbe dominates 90-95% the oral microbiome?
G+ strep or staph
T/F
All oral and facial infections occur from microorganisms already in the mouth
True
What can introduce “outside” oral infections?
Trauma
What would be the most likely culprit causing an oral infection?
G+ strep or staph
______ is the drug of choice for orofacial infections.
Penicillin
What type of Penicillin is the best choice for orofacial infections?
Penicillin V
10% of penicillin is removed from the body via _______.
90% is eliminated via ________.
Glomerular filtration (passive)
Tubular Secretion (active)
T/F
Penicillin stays in the body a long time
False
*excreted rapidly
____% of an oral dose of penicillin is excreted within ____ hrs.
70%
4 hrs
T/F
Penicillin is excreted unchanged
True
What drug, used to treat gout, is often given before penicillin?
How does it treat gout?
Probenecid (benemid)
Prevents uric acid reabsorption into blood stream
How does Probenecid (benemid) compete with penicillin?
Excretory Active Transport system
*Probenecid has higher affinity for excretory process
Giving Probenecid (benemid) prior to Penicillin will elevate the serum blood levels of Penicillin by _____.
3-4 times
*prolongs effect of penicillin
What enzyme breaks dow the beta lactam ring of the Penicillin molecule?
Penicillinase
What type of Penicillin has the following profile:
Bactericidal
Narrow Spectrum
Acid-labile (70-80% broken down by gastric acid)
Penicillinase-labile
Penicillin G
T/F
Procain Penicillin G is Penicillin-ase labile
True
What type of Penicillin is given either as a repository or IM, is dissolved in oil, and is Penicillinase-labile?
Procain Penicillin G
Name 3 types of Penicillin G.
Penicillin G
Procain Penicillin G
Benzathine Penicillin G
What type of Penicillin is dissolved in oil and given as a repository or IM, is Penicillinase-labile and is the longest lasting form of penicillin?
Benzathine Penicillin G
Given a ______ IM dose after aqueous penicillin, this is the longest lasting form because of no GI absorption.
Benzathine Penicillin G
How long does Benzathine Penicillin G last in the plasma?
3 weeks
What is the improved, acid stable version of Penicillin G?
aka?
Penicillin V
sodium penicillin V
How is Penicillin V taken?
Orally
***not broken down by gastric acid
What increases the bioavailability of Penicillin V?
Potassium salt
Does penicillinase break down Penicillin V?
Yes
*penicillin-ase labile
Name 4 Penicillinase resistant drugs:
these are only given for infections with penicillinase producing bacteria
Cloxacillin (canadian)
Dicloxacillin (canadian)
Piperacillin and tazobactam sodium
Ticarcillin and clavulanate potassium
What is a Bactericidal, broad spectrum, acid stable, but penicillinase-labile form of Penicillin?
Ampicillin
Principen with Probenecid is a ______ spectrum form of penecillin
Broad Spectrum
Describe Amoxicillin (Amoxil)
2 things
Broad Spectrum
Penicillinase-labile
______ is added to Amoxicillin to make ______
Clavulanic Acid
Augmentin
T/F
Augmentin is peniccillinase labile
False
*inhibits beta lactamase
Name 4 Narrow Spectrum forms of Penicillin:
Penicillin G
Procain Penicillin G
Benzathine Penicillin G
Penicillin V
Name 4 Broad Spectrum forms of Penicillin:
Ampicillin
Principen with Probenecid
Amoxicillin
Augmentin
What is the synthetic, beta lactamase inhibiting, broad spectrum antibiotic?
What is it a combination of?
Augmentin
Clavulanic acid and Amoxicillin
Name are 3 general adverse affects of penicillin:
Oral Candidiasis
Black hairy tongue
Allergy
What type of reaction can Amoxicillin-toxicity induce?
Maculopapular rash
What type of reaction can Augmentin induce?
Diarrhea
Name 2 types of Repository Penicillin:
Procaine Penicillin G
Benzathine Penicillin G
How does Penicillin work?
Structural glycopeptide interference in bacterial cell wall synth.
Cell lysis
(bactericidal)
The bacterial spectra of Penicillins can be _____ or ______.
The bacterial spectra of Cephalosporins are _____ in the 1st Generation and _______ in the higher generations.
Narrow, broad
Narrow, Broad
Match the following toxicity rxns:
Oral candidiasis, black hairy tongue, maculopapular rash, diarrhea, allergy
Anaphylaxis, fever, rash, eosinophilia, GI upset, glossitis, stomatitis, candidiasis, nephrotoxicity
Penicillins
Cephalosporins
T/F
Pts that are intolerant to penicillin may be intolerant to cephalosporins
True
Describe Cephalosporins mechanism of action:
What kind of bacteria are most susceptible to Cephalosporins?
similar to penicillin - inhibit bacterial cell wall synthesis
Rapidly dividing bacteria most susceptible
Most Cephalosporin absorption occurs in the ______.
This is efficient because…
GI tract
Acid stable (no destruction is stomach like penicillin)
T/F
Most penicillins are acid labile so are destroyed by gastric juices
True
What type of penicillin is more acid stable and therefore has more uniform absorption?
Penicillin V
Name 3 1st generation Cephalosporins (with generic names)
Cephalexin (keflex)
Cefadroxil (duricef)
Cephradine (velosef)
Name the Second Generation Cephalosporin we need to know (including generic)
Cefaclor (raniclor)
Name 3 macrolide antibiotics:
Erythromycin
Azithromycin
Clarithromycin
Name the 6 side effects of Macrolide antibiotics
erythromycin, azithromycin, clarithromycin
GI
Cholestatic jaundice (hepatitis)
Allergic rxns
Fever
Eosinophilia
Skin eruptions
Name 4 GI side effects of Macrolide antibiotics (erythromycin, azithromycin, clarithromycin)
Stomach pain
Nausea/vomiting
Cramps
Diarrhea
Erythromycin is usually _____, but ______ at high doses or when used against susceptible organisms.
Bacteriostatic
Bactericidal
Erythromycin is only effective against ________ organisms.
Actively Dividing
How does Erythromycin attack bacteria?
what does it bind? near what? inhibits?
Binds 50S ribosomal subunit
near peptidyltrasferase
peptide bond formation
***suppresses bacterial growth due to lack of protein production
Where is Erythromycin absorbed?
Upper part of intestine
T/F
Food reduces the absorption of Erythromycin
True
T/F
The effectiveness of Erythromycin is dependent on derivative, dosage, acid stability, and gastric emptying
True
T/F
Erythromycin is absorbed topically through mucous membranes
False
*Unknown
Describe 2 Aspects of Erythromycin distribution:
Crosses placenta
Distributed to most body tissues (diffuses readily)
Most Erythromycin is excreted _______ due to ______.
in Feces
its large size
Erythromycin is absorbed from the _____ to the Liver and excreted in the bile.
How can this affect the Bile Duct?
Stomach
Smooth muscles constrict = Cholestatic Hepatitis
Erythromycin is excreted primarily in the _____ and secondarily in the ______.
Feces
Urine
________ is the primary Macrolide used for antibiotic premedication in Dentistry
________ and ______ are the alternative macrolide antibiotics. (with Brand names)
Erythromycin
Clarithromycis (Biaxin) and Azithromycin (Zithromax)
What antibiotic has a similar mechanism to Erythromycin?
interferes with bacterial protein synth
Clindamycin
Clindamycin is used for infections caused by ________ organisms.
Anaerobic
What is the drug of choice if penicillin resistant and have an orofacial infection?
Clindamycin
What are 3 cases that would indicate Clindamycin use?
Periodontal/orofacial infections by anaerobes
Anaerobic osteomyelitis (oral bone infection)
Endodontic infections caused by Bacteroides
T/F
Clindamycin is effective at penetrating bone and therefore prescribed for Anaerobic Osteomyelitis
True
What 2 classes of Antibiotics are most often associated with C. diff?
Clindamycin
Cephalosporins
(C, C, C)
What drug is affected by divalent cations in GI absorption?
Tetracycline
Why do divalent cations affect Tetracycline so much?
What is this process called?
4 ring structure with OH and O groups
Chelation
Ca, Mg, Fe, and Al chelated Tetracycline when _____ is consumed.
Dairy
What conditions are contraindicated for Tetracycline administration?
Children developing teeth/bone
Pregnancy
What can be incorporated into teeth/bone through chelation?
*causes pitting and yellowing
Tetracycline
Tetracyclines are Category _____ and cross the Placenta.
D
Why do the chelating effects of Tetracycline incorporating into the enamel become permanent?
Enamel doesn’t remodel like bone
T/F
Teeth exposed to Tetracycline fluoresce under a black light.
True
What is a reversible effect of Tetracycline exposure in children?
What is an irreversible effect?
Bone deposition
May inhibit skeletal growth
Name 3 Tetracycline preparations:
Doxycycline
Minocycline
Tetracycline
Doxycycline _____, aka ______, inhibits collagenase only (doesn’t kill bacteria) at a subantimicrobial dose.
Hyclate
Periostat
Tetracyclines are contraindicated with _______/_______.
Penicillin/Amoxicillin
Tetracycline is bacterio_______, while penicillin is bacterio______.
Static
Cidal
What is an example of another antibiotic that can be prescribed if a patient is already taking Tetracycline?
What kind of antibiotic must be prescribed?
Clindamycin
Bacteriostatic
*static and cidal have antagonistic effects
What are 3 Contraindications for Tetracycline?
Pregnancy
Child
Penicillin/Amoxicillin use
What are 3 medical indications for Quinolones?
Respiratory infections
Bronchitis, community acquired pneumonia
Urinary tract infections
What is a Dental indication for Quinolones?
Periodontal disease when other agents ineffective
***rarely used in Dentistry
Quinolones target _______.
DNA topoisomerases
The enzyme that relieves tension in DNA as it uncoils is a _______.
________’s target these enzymes to block bacterial replication, transcription, and repair.
Topoisomerase
Quinolones
Quinolones are Bacteri_____ and _____ spectrum.
Bactericidal
Broad
Describe 3 Adverse events broght on by Quinolones.
GI - Nausea/vomiting, diarrhea, xerostomia
CNS - headache, dizzy, vertigo syncope
Allergy - pruritis (itching), urticaria (hives)
What drug deactivates critical enzymes in Anaerobic Bacteria through a cascade of reduction (ferredoxin, pyruvate oxido-reductase, nitroso intermediates) that creates Sulfinamides?
150 enzymes affected
Metronidazole
Metronidazole metabolites can also be taken up into ________ and form unstable molecules.
Why does this have little effect on human cells?
Anaerobic Bacterial DNA
Partial reduction of Metronidazole only happens in anaerobic cells
T/F
Metronidazole is used to supplement other antibiotics when a perio condition isn’t responding to other treatments.
True
3 Common adverse side effects of antibiotics:
Candidiasis (black hairy tongue)
Stomatitis (sore mouth)
Glossitis (tongue inflammation)
How do antibiotics interfere with oral contraceptives?
Oral contraceptives activated by gut flora
If gut flora damaged, possible ovulation
***use alternative birth control until next cycle
Where is the site of antibiotic/oral contraceptive interaction?
Small intestine
Warfarin/coumadin (anticoagulant) is affected by antibiotics how?
Antibiotics kill Warfarin’s competition - gut flora gobbling up VitaK.
***can experience excessive anticoagulation
What class of antibiotics is particularly harmful to gut bacteria and therefore compounds effects of Warfarin/coumadin due to lack of Vitamin K?
Quinolones (cipro)
Histamines cause ______, which drops bp
Vasodilation
T/F
Tachycardia and reddening of the skin due to vasodilation are consequences of Histamine
True
What receptors does Histamine react with in the CV system?
H1
What receptors does Histamine react with in the Respiratory tract?
H1
Describe Histamines actions in the Respiratory tract:
4 things
Constriction resp smooth muscle
Difficulty breathing
Prostaglandin formation
Inflames airways
In the GI tract Histamine acts on Gastric Acid secretion (HCl) through ____ receptors.
Contracts the Ileum through _____ receptors.
H2
H1
What do Antihistamines block?
Histamine Receptors (H1 or H2)
*antagonists
T/F
Both H1 and H2 mechanism of action for Antihistamines is competitive blockage of receptors
True
What is the primary and 2 secondary adverse side effect of antihistamines?
primary - sedation
secondary - xerostomia and CNS
T/F
Antihistamines affect children and the elderly differently
True
*stimulation instead of drowsiness (also convulsions)
**also seen in very large doses
H1 antihistamine mechanism is competitive blockage. H2 is competitive blockage that reduces what? where? consequence?
cAMP, protein kinase, H/K pump
stomach
inhibits basal/nocturnal HCl (gastric acid) secretion
What are the clinical uses of H2 Antihistamines?
GI disorders
*ulcers, GERD, gastric acid hypersecretion, Zollinger-Ellison syndrome
What is Zollinger-Ellison syndrome?
Gastrin producing tumor
*hypersecretion HCl
H1 antihistamine clinical use includes allergy, pollinosis, urticaria (localized with wheals), anaphylaxis - what are the off-label uses (5)?
Motion sickness
Nausea/vomiting
Dizziness
Sleep
Local anesthetics
In oral form antihistamines reverse ______.
In injected form antihistamines reverse _______.
In liquid form antihistamines are for _______.
minor allergic rxns (or pre-op sedation)
major allergic rxns
topical anesthetic (injected in rare cases, used for pts allergic to other locals)
What are 3 non-sedating antihistamines?
loratadine (Claritin)
fexofenadine (Allegra)
desloratadine (Clarinex)
What is the major side effect of laratadine, fexofenadine, and desloratatine? (Claratin, Allegra, Clarinex)?
Headache
*have long half lives
Name 3 Sedating Antihistamines:
Ehanolamines (dophenhydramine/Benadryl)
Alkylaminies (chlorpheniramine/Clor-Trimeton)
cetirizine (Zyrtec)
If you have to inject benadryl (ethanolamine) in emergency, how much?
Daily max?
10-50 mg
400 mg
What is the primary ingredient in non-habit forming sleep aids like Sminex and Nytol?
Ethanolamine (diphenhydramine/Benadryl)
T/F
Off label use of Ethanolamine, unapproved by the FDA, includes insomnia, motion sickness (like Dramamine), nausea, and vomiting
True
Alkylamines can be injected in dental emergencies/anaphylaxis at ____ mg and max ____mg daily
10
40
What popular OTC antihistamine is approved for treatment of all types of allergens and causes sedation?
cetirazine (Zyrtec)
What are 4 H2 receptor blockers used for ulcers/heartburn?
Most dangerous?
Safest?
cimetadine (Tagamet) *most adverse rxns - inhibits cytoP450
famotidine (Pepcid)
nizatidine (Axid)
ranitidine (Zantac) *safest
T/F
Immunosuppression, systemic disease, chemo, antibiotics, and hormones can all lead to fungal infections
True
*opportunistic = candida albicans
“cottage cheese”, pseudomembanous, atrophic tongue, hyperkeratotic appearance, symptomatic geographic tongue, and angular chelitis are all what?
Oral fungal infections
Name 3 antifungal agents useful agains Candida albicans:
nystatin (Mycostatin)
clotrimazole (Mycelex)
amphotericin (Amphocin, Fungizone)
T/F
Topical vs systemic therapy is preferred for fungal infection
True
T/F
Systemic fungal drugs suck b/c they cause dangerous DDI’s, promote resistance, and are toxic
True
Troches, Pastilles, liquids, and powders are all _____ treatments.
Topical
Chorhexidine/Listerine kill ____ species of Candida
7
Nystatin binds ____ in fungal cell membrane
Sterols
*changes cell permeability and leaks cell contents
What azole has severe CV side effects including neuropathy?
Itraconazole
Topical treatment of oral fungal infections is used for minimum of ____ hours after symptoms subside, and the usual treatment is ____ weeks.
*reevaluated?
48 hours
1-2 weeks
*14 days after therapy
Because topical agents must be used 5 times/day for 1-2 weeks, what can be a problem?
Compliance
What drug is incorporated into viral DNA and inhibits DNA polymerase preferentially?
acyclovir (Zovirax)
5 antivirals used to manage Herpes?
acyclovir (Zovirax)
valacyclovir (Valtrex)
penciclovir (Denavir)
docosanol (Abreva)
alcohol/benzalkonium chrolide (Viroxyn)
What antiviral treats both HSV1 and HSV2?
acyclovir (Zovirax)
*every 3 hrs apply or no result
What antiviral treats HSV2 only (genital)?
valacyclovir (Valtrex)
What 3 antivirals treat HSV1 only?
penciclovir (Denavir)
docosanol (Abreva)
alcohol/benzalkonium chloride (Viroxyn)
What antiviral must be applied every 3 hrs or no results?
What antiviral is given in 2 doses?
what antiviral is applied every 2 hrs for 4 days?
what antiviral is applied 5 times/day? (never around eyes)
what antiviral is cauterizing and stings?
acyclovir (Zovirax)
valacyclovir (Valtrex)
penciclovir (Denavir)
docosanol (Abreva)
alcohol/benzalkonium chrolide (Viroxyn)
Name 2 side effects of systemic antivirals:
Bone marrow suppression
Blood dyscrasias (thrombocytopenia, leukopenia, aplastic anemia)
