Transcript Pharmacology - Cheryl Davis

ANTIVIRALS &
ANTIBACTERIALS
Cheryl Davis-Triplett
WHAT IS A VIRUS?


Obligate intracellular
organism that uses
the cell to
reproduce. They
replicate by using
their own RNA or
DNA to manipulate
the cells they infect
They cause cell
death
WHAT IS A BACTERIA?
 Smallest
living cell.
They have a cell
wall and a cell
membrane. They
do not have a
nucleus.
 Bacteria divide by
cell division.
HOW DO WE FIGHT BACTERIA
AND VIRUSES
 Antibacterials
work
with the body’s
own defenses to
stop the infection
process.
 Antivirals
prevent
or delay the speed
of viral replication.
ANTIBACTERIAL MODE OF
ACTION
 Inhibit
cell wall
synthesis. Which
Antibiotic class
uses this mode?
 Penicillins and
Cephalosporins
 Inhibit
protein
synthesis. Which
Antibiotic class
uses this mode?
 Tetracyclines,
Macrolides, and
Aminoglydosides
MODE OF ACTION (cont.)
 Inhibit
nucleic acid
synthesis. Which
Antibiotic class
uses this mode?
 Fluoroquinolones
 Inhibit
folic acid
synthesis. Which
Antibiotic class
uses this mode?
 Sulfonamides
MODE OF ACTION (cont.)
 Alteration
in
membrane
permeability.
Which drugs use
this mode?
 Ampho-TERRIBLE B,
Nystatin, Polymyxin,
and Colistin
ANTIVIRAL MODE OF ACTION
 Viruses
enter
healthy cells and
use their
deoxyribonucleic
acid (DNA) and
ribonucleic acid
(RNA) to generate
more viruses.
 The
growth cycle
of viruses depends
on the host cell
enzymes and cell
substrates for viral
replication.
 Viruses live and
reproduce when
they are within
living cells.
OVERVIEW
 Penicillins

 Cephalopsporins
 Macrolides
 Tetracyclines

 Aminoglycosides

 Fluorquinalones
 Sulfonomides
 Antivirals


Viral flu treatment
(drugs and
how/when they are
given)
Herpes simplex
Aminoglycosides
(SE/ADEs, drug-drug)
Otitis media
treatment
Amphotericin B
Common factors among
Antibiotics
 Indications:
bacterial infections
 SE/AD: superinfections, NVD
 Contraindications: hypersensitivity
 Interventions: C&S
 Pt Teaching: S&S hypersensitivity, finish
prescribed dose, medical alert bracelet
PENICILLIN
Indication for Use
 Respiratory tract
infection
 Urinary tract
infection
 Otitis media
 Sinusitis
Example Drug
 Amoxicillin(Amoxil)
PENICILLIN (cont.)



Side Effects
NVD, rash, edema,
stomatitis
AR: Super Infections
(vaginitis)
Life threatening:
Blood dyscrasias,
hemolytic anemia,
bone marrow
depression,
respiratory distress
Contraindications
 Allergy to penicillin
 Severe renal
disorder
PENICILLIN (cont.)
Interactions
 Drug: asprin,
tetracycline,
erythromycin.
 Lab: AST, ALT, BUN,
and creatinine.
 Food: acidic fruits
or juices.
High Risk Populations
 Geriatrics
PENICILLIN



Nursing Process
Assess allergy to
penicillin or
cephalosporin.
Interventions: don’t
mix aminoglycosides
w/ penicillin G, check
for bleeding, monitor
temperature, dilute IV
antibiotic.
Evaluate effectivess of
med by determining if
infection ceased and
whether SE have
occurred.



Client Education
encourage client to
increase fluid intake
instruct client that
chewable tablets
must be chewed or
crushed before
swallowing
advise client to take
medication with
food to avoid GI
irritation.
CEPHALOSPORIN
Indications for Use
Skin, urinary and
respiratory infections.
Can also treat
genital, bone joint
infections and
endocarditis.
Example DRUG
 Cefazolin (Ancef),
(Ketzol)
CEPHALOSPORIN (cont.)
Side Effects
Anorexia, NVD, rash,
abdominal cramps
AR: superinfections,
urticaria LIFE THREAT:
seizures (high doses),
anaphylaxis
Contraindications
Hypersensitivity to this
antibiotic, watch for
PCN allergies. Renal
disease, lactation for
mothers
CEPHALOSPORIN (cont.)
Interactions
Drug:
 ETOH
 loop diuretics,
aminoglycosides,
 tetracyclines and
erythromycin
Lab:
 BUN, serum
creatinine, AST, ALT,
ALP, LDG, and
bilirubin.
High Risk Populations
 persons allergic to
PCN may also be
allergic to
cephalosporins
CEPHALOSPORIN
Nursing Process
 record VS and
urine output
 check lab results
especially those
that indicate renal
and liver functionreport abnormal
findings
Client Education
 advise client to
ingest buttermilk or
yogurt to prevent
superinfection of
the intestinal flora,
 infuse IV
cephalosporins
over 30min
MACROLIDE
Indications for Use
For patients with PCN
allergies
treats gram positive
and some gram
negative bacteria,
respiratory and skin
infections and
gonorrhea
Example DRUG
 Azithromycin
(Zithromax),
(AzaSite)
MACROLIDE (cont.)
Side Effects
SE: NVD,anorexia, rash,
tinnitus, pruritus AR:
hearing loss, vaginitis,
superinfections, stomatitis
LIFE THREAT:
Hepatotoxicity,
anaphylaxis
Uncommon: abdominal
Pain , diarrhea(p. 427)
Contraindications
Hepatic or renal
dysfunction,
hypersensitivity,
lactaction
MACROLIDE (cont.)
Interactions
Drug:
 digoxin, theophylline
(bronchodilator), and
warfarin (anticoagulant)
 penicillins and
clindamycin
 antacids
 clindamycin or
lincomycin
Food:
 administer 1 h before or
2 h after meals.
 fruit juice.
High Risk Populations
 Liver toxicity can
occur if taken with
high doses of other
hepatogoxic drugs
(acetaminophen),
phenothiazines,
and sulfonamides.
MACROLIDE
Nursing Process






check lab tests to determine
liver function,
obtain a Hx of drugs client
takes-peak level of
azithromycin may be
decreased by antacids
Interventions: monitor vital
signs and client for liver
damage resulting from
prolonged use
administer oral meds 1hr
before or 2hrs after meals
do not give w/ fruit juice,
dilute IV meds
administer antacids 2hrs
before or 2hrs after
azithromycin.
Client Education
 Instruct client to
take the full course
of antibacterial
agent as
prescribed. Drug
compliance is most
important for all
antibacterials
(antibiotics).
TETRACYLINE
Indications for Use
Treat both gram
positive and gram
negative bacteria,
skin and respiratory
infections, syphilis,
gonorrhea,
chlamydia, ricketts
and rosacea
Example DRUG
 Doxycline
(Vibramycin),
(Vibra-Tabs)
TETRACYCLINE (cont.)
Side Effects
Abdominal discomfort,
rash, HA, pruritus, color
vision change,
photosensitivity
AR: superinfection and
severe photosensitivity
LIFE THREAT:
Hepatotoxicity, blood
dyscrasias, intracranial
HTN,
psuedomembranous
colitis
Contraindications
Severe renal or
hepatic disease,
pregnancy,
hypersensitivity,
Caution:
hypokalemia,
bradycardia,
alcoholics,
antidysrythmics
TETRACYCLINE (cont.)
Interactions



Drug:
digoxin
antacids, iron, and
zinc,
oral contraceptives,
lithium levels
Lab: potassium level
Food: Dairy products
(milk, cheese)
High Risk Populations
 teratogenic effects
 children less than 8
should not use due
to discoloration of
permanent teeth
TETRACYCLINE
Nursing Process
 Assess vital signs and urine
output-report abnormal
findings,
 check lab results especially
renal and liver function
 obtain a Hx of dietary
intake and drugs client is
currently taking.
Interventions:
 administer tetracycline 1hr
before or 2 hrs after meals
 monitor lab values for liver
and kidney function
 record VS and urine
output.
Client Education
 Storage of
tetracycline
 expiration date
 teratogenic effects
 discoloration of
permanent teeth in
children <8, advise
AMINOGLYCOSIDE
Indications for Use
Gram-negative
bacteria can cause
serious infections.
Treats PID, effective
against methicillianresistant and
staphylococcus
infections
DRUG
 Gentamicin Sulfate
(Garamycin)
AMINOGLYCOSIDE (cont.)
Side Effects
Tremors, numbness, rash,
muscle cramps or
weakness, anorexia,
visual disturbance AR:
Oliguria, uticaria,
palpations,
superinfection LIFE
THREAT: nephrotoxicity,
agranulocytosis,
neuromuscular block,
ototoxicity and liver
damage
Contraindications
Sever renal disease,
hypersensitivity,
lactation,
pregnancy, Caution:
renal disease, heart
failure, myasthenia
gravis, parkinsonism,
older adults,
neonates
AMINOGLYCOSIDE (cont.)


Interactions
Drug: Increase risk of
ototoxicity with loop
diuretics, increase risk of
nephrotoxicity with
amphotericin B,
furosemide, and
vancomycin
Lab: Increase BUN,
serum AST, ALT, LDH,
bilirubin, creatinine,
decrease serum
potassium and
magnesium
High Risk Populations
 Nephrotoxicity is
dependent on drug
dose, renal function,
and age. Age:
young and older
clients should be
assessed for signs of
toxicity: hearing,
balance, urinary
output.
AMINOGLYCOSIDE


Nursing Process
Assess VS and urine
outpute and compare
these results w/ future VS
and urine output, assess
renal function, liver
function and electrolytes,
assess Hx of renal or
hearing disorders.
Interventions: Send sample
to lab for C&S, monitor
I&O, urinalysis may be
ordered daily, check for
hearing loss, monitor VS,
and note if body
temperature has
decreased.
Client Education
 Unless fluids are
restricted,
encourage client
to increase fluid
intake.
 Instruct client never
to take leftover
antibiotics.
FLOUROQUINOLONE
Indications for Use
Respiratory infections
(moderate to
severe), renal and
bone infections
DRUG
 Levofloxacin
(Levaquin)
FLOUROQUINOLONE (cont.)
Side Effects
Abdominal cramps,
HA, fatigue, dizziness,
restlessness, flushing,
rash, flatulence,
photosensitivity, tinnitus
AR: Steven-Johnson
syndrome,
encephalopathy,
dysrythmias, seizures,
psuedo-membranous
colitis.
Contraindications
Severe renal disease,
hypersensitivity to other
quinolones,
breastfeeding,
pregnancy Caution:
renal disorders,
children <14 or older
adults, patients taking,
theophylline, seizures
FLOUROQUINOLONE (cont.)


Interactions
Drug: Increase effect
of oral
hypoglycemics,
theophylline, and
caffeine, decrease
drug absorpotion
with antacids and
iron
Lab: Increase AST
and ALT
High Risk Populations
 Diabetes Mellitus:
monitor blood
sugar. Levofloxacin
can increase
effects of oral
hypoglycemics.
FLOUROQUINOLONE


Nursing Process
Record VS and I&Ocompare w/ future results,
assess lab results for renal
function, obtain a drug
and diet Hx
Interventions: Send
specimen to lab for C&S,
monitor I&O, recort VS and
report abnormal findings,
check lab results for liver
dysfunction, administer
meds 2hrs before or after
antacids and iron products,
take w/ a full glass of
water, if GI distress occurs,
take w/ food, check serum
theophylline levels, monitor
blood sugar
Client Education
 Teach client to
drink at least 6 to 8
glasses of fluid
daily. Encourage
client to avoid
caffeinated
products.
SULFONAMIDE
Indications for Use
 To treat urinary
tract infection, otitis
media, bronchitis,
pneumonia,
pneumocystis
carinii; infection,
rheumatic fever,
burns
DRUG
 sulfamethoxazoleTrimethroprim/TMPSMZ (Bactrim),
(Septra)
SULFONAMIDE (cont.)
Side Effects
SE: Anorexia, rash,
stomatitis, fatigue,
depression, headache,
vertigo, photosensitivity.
AR: LIFE THREAT:
leukopenia,
thrombocytopenia,
increased bone marrow
depression, hemolytic
anemia, aplastic anemia,
agranulocytosis,StevensJohnson syndrome, renal
failure
Contraindications
Severe renal or
hepatic disease,
hypersensitivity to
sulfonamides
SULFONAMIDE (cont.)


Interactions
Drug: Increase
anticoagulant effect
with warfarin,
increase
hypoglycemic effect
with oral
hypoglycemic drugs
Lab: May increase
BUN, serum
creatinine, AST, ALT,
and ALP
High Risk Populations
 Clients with AIDS
are more
susceptible to TMPSMZ toxicity
SULFONAMIDE


Nursing Process
Assess client’s renal
function, obtain medical
and drug Hx, determine if
client is hypersensitive to
sulfonamides, assess
baseline lab results
especially CBC.
Interventions: Administer w/
a full glass of water,
monitor VS, Observe client
for hematologic reactions
that may lead to lifethreatening anemias,
check for S&S of
superinfection.

Client Education
Instruct client to take
several quarts of fluid daily,
advise pregnant clients not
to take during the last 3
months of pregnancy,
inform client not to take
antacids w/ sulfonamides,
warn client who has an
allergy to one sulfonamide
that all sulfonamide
preparations should be
avoided, with health care
provider’s approval,
because of the possibility
of cross sensitivity.
ANTIVIRAL
Indications for Use
There are groups of
antiviral drugs effective
against various viruses
such as influenza A
and B, herpes species,
cytomegalovirus
(CMV), and human
immunodeficiency
virus (HIV).



DRUG
Purine NucleosidesAcyclovir Sodium
(Zovirax)
Systemic Non HIVamantadine HCI
(Symmetrel)
Neuraminidase
Inhibitors- oseltamivir
phosphate (Tamiflu)
ANTIVIRAL (cont.)
Side Effects
HA, tremors, lethargy, rash,
pruritus, increased bleeding
time, phlebitis at IV site AR:
Uticaria, anemia, gingival
hyperplasia. LIFE THREAT:
neuropathy, seizures,
nephrotoxicity (large doses),
bone marrow depression,
thrombocytopenia,
leukopenia,
granulocytopenia
Contraindications
Hypersensitivity,
severe renal or
hepatic disease.
Caution: electrolyte
imbalance, nursing
mothers, young
children
ANTIVIRAL (cont.)
Interactions
 Drug: Increase
nephroneurotoxicity with
aminoglycosides,
probenecid, and
interferon
 Lab: May increase
AST, ALT, and BUN
High Risk Populations
 Cervical cancer is
more prevelant in
women with
genital herpes,
these women
should have a PAP
smear twice a year
ANTIVIRAL
Nursing Process


Obtain a medical Hx from
client of any serious renal or
hepatic disease, determine
baseline VS and a CBC to
use for comparison of future
results, assess baseline lab
results for future comparison,
assess baseline VS and urine
output.
Interventions: Check clients
CBC, record urine output,
note VS especially BP,
observe for S&S of SE, check
for superinfection, dilute IV
drug and administer over 60
min, never give acyclovir as
a bolus (IV push).

Client Education
Advise client to maintain
adequate fluid intake to
ensure sufficient
hydration for drug
therapy and increase
urine output, instruct
client w/ genital herpes
to avoid spreading
infection by practicing
sexual abstinence or by
using condoms, Direct
clients taking zidovudine
to have blood cell
count monitored.
Quiz Time !!!!!
REFERENCES
Ryan, K. J., Ray, C. G., (2004). Medical Microbiology: An introduction to infectious disease (4th ed).
New York, NY. McGraw-Hill, Unit 1.