5. Antibiotics
– Medications used to treat bacterial infections
– Ideally, before beginning antibiotic therapy, the
suspected areas of infection should be cultured to
identify the causative organism and potential
antibiotic susceptibilities.
6. Antibiotics
– Empiric therapy: treatment of an infection before
specific culture information has been reported or
obtained
– Prophylactic therapy: treatment with antibiotics to
prevent an infection, as in intra-abdominal surgery
7. Antibiotics
– Bactericidal: kill bacteria
– Bacteriostatic: inhibit growth of susceptible
bacteria, rather than killing them immediately; will
eventually lead to bacterial death
8. Antibiotics: Sulfonamides
– One of the first groups of antibiotics
– sulfadiazine
– sulfamethizole
– sulfamethoxazole
– sulfisoxazole
9. Sulfonamides: Mechanism of Action
– Bacteriostatic action
– Prevent synthesis of folic acid required for
synthesis of purines and nucleic acid
– Does not affect human cells or certain bacteria—
they can use preformed folic acid
10. Sulfonamides: sulfamethoxazole
Therapeutic Uses
– Azo-Gantanol
– Combined with phenazopyridine (an analgesic-
anesthetic that affects the mucosa of the urinary
tract).
– Used to treat urinary tract infections (UTIs) and to
reduce the pain associated with UTIs .
– Bactrim
– Combined with trimethoprim.
– Used to treat UTIs, Pneumocystis carinii pneumonia,
ear infections, bronchitis, gonorrhea, etc.
11. Sulfonamides: sulfisoxazole
Therapeutic Uses
– Azo-Gantrisin
– Combined with phenazopyridine
– Used for UTIs
– Pediazole
– Combined with erythromycin
– Used to treat otitis media
12. Sulfonamides: Side Effects
– Body System Effect
– Blood Hemolytic and aplastic anemia,
thrombocytopenia
– Integumentary Photosensitivity, exfoliative
dermatitis, Stevens-Johnson syndrome, epidermal
necrolysis
13. • Sulfonamides: Side Effects
– Body System Effect
– GI Nausea, vomiting, diarrhea, pancreatitis
– Other Convulsions, crystalluria, toxic nephrosis,
headache, peripheral neuritis, urticaria
18. • Antibiotics: Penicillins
– First introduced in the 1940s
– Bactericidal: inhibit cell wall synthesis
– Kill a wide variety of bacteria
– Also called “beta-lactams”
19. • Antibiotics: Penicillins
– Bacteria produce enzymes capable of destroying
penicillins.
– These enzymes are known as beta-lactamases.
– As a result, the medication is not effective.
20. • Antibiotics: Penicillins
– Chemicals have been developed to inhibit these
enzymes:
• clavulanic acid
• tazobactam
• sulbactam
– These chemicals bind with beta-lactamase and
prevent the enzyme from breaking down the
penicillin
22. • Penicillins: Mechanism of Action
– Penicillins enter the bacteria via the cell wall.
– Inside the cell, they bind to penicillin-binding
protein.
– Once bound, normal cell wall synthesis is
disrupted.
– Result: bacteria cells die from cell lysis.
– Penicillins do not kill other cells in the body.
23. • Penicillins: Therapeutic Uses
– Prevention and treatment of infections caused by
susceptible bacteria, such as:
• gram-positive bacteria
• Streptococcus, Enterococcus, Staphylococcus species
24. • Penicillins: Adverse Effects
– Allergic reactions occur in 0.7% – 8% of
treatments
• urticaria, pruritus, angioedema
– 10% of allergic reactions are life-threatening
– and
– 10% of these are fatal
25. • Penicillins: Side Effects
– Common side effects:
• nausea, vomiting, diarrhea, abdominal pain
– Other side effects are less common
27. • Antibiotics: Cephalosporins
– Semisynthetic derivatives from a fungus
– Structurally and pharmacologically related to
penicillins
– Bactericidal action
– Broad spectrum
– Divided into groups according to their
antimicrobial activity
29. • Cephalosporins: First Generation
– cefazolin cephalexin
– (Ancef and Kefzol) (Keflex and Keftab)
– IV and PO PO
• used for surgical prophylaxis, URIs, otitis media
30. • Cephalosporins: Second Generation
– cefaclor • cefonicid
– cefprozil • ceforanide
– cefamandole • cefmetazole
– cefoxitin • cefotetan
– cefuroxime
• Good gram-positive coverage
• Better gram-negative coverage than first generation
31. • Cephalosporins: Second Generation
– Cefoxitin cefuroxime
– (Mefoxin) (Kefurox and Ceftin)
– IV and IM PO
– Used prophylactically for Surgical prophylaxis
abdominal or colorectal surgeries Does not kill
Also kills anaerobes anaerobes
32. • Cephalosporins: Third Generation
– cefixime • ceftizoxime
– cefpodoxime proxetil • ceftriaxone
– cefoperazone • ceftazidime
– cefotaxime • moxalactam
• Most potent group against gram-negative
• Less active against gram-positive
33. • Cephalosporins: Third Generation
– cefixime (Suprax)
– Only oral third-generation agent
– Best of available oral cephalosporins against gram-
negative
– Tablet and suspension
– ceftriaxone (Rocephin)
– IV and IM, long half-life, once-a-day dosing
– Easily passes meninges and diffused into CSF to treat
CNS infections
34. • Cephalosporins: Third Generation
– ceftazidime (Ceptaz, Fortaz, Tazidime, Tazicef)
– IV and IM
– Excellent gram-negative coverage
– Used for difficult-to-treat organisms such as
Pseudomonas spp.
– Eliminated renally instead of biliary route
– Excellent spectrum of coverage
35. • Cephalosporins: Fourth Generation
– cefepime (Maxipime)
– Newest cephalosporin agents.
– Broader spectrum of antibacterial activity than
third generation, especially against gram-positive
bacteria.
38. • Antibiotics: Tetracyclines
– Natural and semi-synthetic
– Obtained from cultures of Streptomyces
– Bacteriostatic—inhibit bacterial growth
– Inhibit protein synthesis
– Stop many essential functions of the bacteria
39. • Antibiotics: Tetracyclines
– Bind to Ca 2+ and Mg 2+ and Al 3+ ions to form
insoluble complexes
– Thus, dairy products, antacids, and iron salts
reduce absorption of tetracyclines
40. • Tetracyclines: Therapeutic Uses
– Wide spectrum:
• gram-negative, gram-positive, protozoa, Mycoplasma,
Rickettsia, Chlamydia, syphilis, Lyme disease
– Demeclocycline is also used to treat SIADH, and
pleural and pericardial effusions
41. • Tetracyclines: Side Effects
– Strong affinity for calcium
– Discoloration of permanent teeth and tooth
enamel in fetuses and children
– May retard fetal skeletal development if taken
during pregnancy
42. • Tetracyclines: Side Effects
– Alteration in intestinal flora may result in:
– Superinfection (overgrowth of nonsusceptible
organisms such as Candida)
– Diarrhea
– Pseudomembranous colitis
43. • Tetracyclines: Side Effects
– May also cause:
– Vaginal moniliasis
– Gastric upset
– Enterocolitis
– Maculopapular rash
46. • Aminoglycosides
– Natural and semi-synthetic
– Produced from Streptomyces
– Poor oral absorption; no PO forms
– Very potent antibiotics with serious toxicities
– Bactericidal
– Kill mostly gram-negative; some gram-positive
also
47. • Aminoglycosides
– Used to kill gram-negative bacteria such as
Pseudomonas spp., E. coli, Proteus spp., Klebsiella
spp., Serratia spp.
– Often used in combination with other antibiotics
for synergistic effect.
48. • Aminoglycosides
– Three most common (systemic): gentamicin,
tobramycin, amikacin
– Cause serious toxicities:
• Nephrotoxicity (renal failure)
• Ototoxicity (auditory impairment and vestibular [eighth
cranial nerve])
– Must monitor drug levels to prevent toxicities
49. • Aminoglycosides: Side Effects
– Ototoxicity and nephrotoxicity are the most significant
– Headache
– Paresthesia
– Neuromuscular blockade
– Dizziness
– Vertigo
– Skin rash
– Fever
– Superinfections
51. • Quinolones
– Excellent oral absorption
– Absorption reduced by antacids
– First oral antibiotics effective against gram-
negative bacteria
52. • Quinolones: Mechanism of Action
– Bactericidal
– Effective against gram-negative organisms and
some gram-positive organisms
– Alter DNA of bacteria, causing death
– Do not affect human DNA
57. • Macrolides: Therapeutic Uses
– Strep infections
– Streptococcus pyogenes (group A beta-hemolytic
streptococci)
– Mild to moderate URI
– Haemophilus influenzae
– Spirochetal infections
– Syphilis and Lyme disease
– Gonorrhea, Chlamydia, Mycoplasma
58. • Macrolides: Side Effects
– GI effects, primarily with erythromycin:
– nausea, vomiting, diarrhea, hepatotoxicity,
flatulence, jaundice, anorexia
– Newer agents, azithromycin and clarithromycin:
fewer side effects, longer duration of action,
better efficacy, better tissue penetration
59. • Antibiotics: Nursing Implications
– Before beginning therapy, assess drug allergies;
hepatic, liver, and cardiac function; and other lab
studies.
– Be sure to obtain thorough patient health history,
including immune status.
– Assess for conditions that may be
contraindications to antibiotic use, or that may
indicate cautious use.
– Assess for potential drug interactions.
60. • Antibiotics: Nursing Implications
– It is ESSENTIAL to obtain cultures from appropriate
sites BEFORE beginning antibiotic therapy.
61. • Antibiotics: Nursing Implications
– Patients should be instructed to take antibiotics
exactly as prescribed and for the length of time
prescribed; they should not stop taking the
medication early when they feel better.
– Assess for signs and symptoms of superinfection:
fever, perineal itching, cough, lethargy, or any
unusual discharge.
62. • Antibiotics: Nursing Implications
– For safety reasons, check the name of the
medication carefully since there are many agents
that sound alike or have similar spellings.
63. • Antibiotics: Nursing Implications
– Each class of antibiotics has specific side effects
and drug interactions that must be carefully
assessed and monitored.
– The most common side effects of antibiotics are
nausea, vomiting, and diarrhea.
– All oral antibiotics are absorbed better if taken
with at least 6 to 8 ounces of water.
64. • Antibiotics: Nursing Implications
– Sulfonamides
– Should be taken with at least 2400 mL of fluid per
day, unless contraindicated.
– Due to photosensitivity, avoid sunlight and
tanning beds.
– These agents reduce the effectiveness of oral
contraceptives.
65. • Antibiotics: Nursing Implications
– Penicillins
– Any patient taking a penicillin should be carefully
monitored for an allergic reaction for at least 30
minutes after its administration.
– The effectiveness of oral penicillins is decreased
when taken with caffeine, citrus fruit, cola
beverages, fruit juices, or tomato juice.
66. • Antibiotics: Nursing Implications
– Cephalosporins
– Orally administered forms should be given with
food to decrease GI upset, even though this will
delay absorption.
– Some of these agents may cause an Antabuse-like
reaction when taken with alcohol.
67. • Antibiotics: Nursing Implications
– Tetracyclines
– Milk products, iron preparations, antacids, and
other dairy products should be avoided because
of the chelation and drug-binding that occurs.
– All medications should be taken with 6 to 8
ounces of fluid, preferably water.
– Due to photosensitivity, avoid sunlight and
tanning beds.
68. • Antibiotics: Nursing Implications
– Aminoglycosides
– Monitor peak and trough blood levels of these
agents to prevent nephrotoxicity and ototoxicity.
– Symptoms of ototoxicity include dizziness,
tinnitus, and hearing loss.
– Symptoms of nephrotoxicity include urinary casts,
proteinuria, and increased BUN and serum
creatinine levels.
69. • Antibiotics: Nursing Implications
– Macrolides
– These agents are highly protein-bound and will
cause severe interactions with other protein-
bound drugs.
– The absorption of oral erythromycin is enhanced
when taken on an empty stomach, but because of
the high incidence of GI upset, many agents are
taken after a meal or snack.
70. • Antibiotics: Nursing Implications
– Monitor for therapeutic effects:
– Disappearance of fever, lethargy, drainage, and
redness
73. Viruses
• Obligate intracellular parasites
• Consist of a core genome in a protein shell
and some are surrounded by a lipoprotein
• lack a cell wall and cell membrane
• do not carry out metabolic processes
• Replication depends on the host cell
machinery
74. Anti Viral Agents
• Block viral entry into the cell or must work
inside the cell
• Most agents are pyrimidine or purine
nucleoside analogs
75.
76. Understanding Viruses
Viral Replication
• A virus cannot replicate on its own.
• It must attach to and enter a host cell.
• It then uses the host cell’s energy to synthesize protein, DNA,
and RNA.
77. Understanding Viruses
Viruses are difficult to kill because they live
inside our cells.
• Any drug that kills a virus may also kill our cells.
78. Viral Infections
Competent immune system:
• Best response to viral infections
• A well-functioning immune system will eliminate
or effectively destroy virus replication
Immunocompromised patients have frequent viral
infections
• Cancer patients, especially leukemia or lymphoma
• Transplant patients, due to pharmacological therapy
• AIDS patients, disease attacks immune system
79. Antivirals
Key characteristics of antiviral drugs:
• Able to enter the cells infected with virus.
• Interfere with viral nucleic acid synthesis and/or regulation.
• Some agents interfere with ability of virus
to bind to cells.
• Some agents stimulate the body’s immune system.
80. Antivirals
Viruses killed by current antiviral therapy:
• cytomegalovirus (CMV)
• herpes simplex virus (HSV)
• human immunodeficiency virus (HIV)
• influenza A (the “flu”)
• respiratory syncytial virus (RSV)
86. Clinical Uses
Zidovudine
• Available in IV and oral formulations
• activity against HIV-1, HIV-2, and human T cell
lymphotropic viruses
• mainly used for treatment of HIV, decreases
rate of progression and prolongs survival
• prevents mother to newborn transmission of
HIV
88. Tenofavir
• An acyclic nucleoside phosphonate analog of
adenosine
• M.O.A.- competively inhibits HIV reverse
transcriptase and causes chain termination
after incorporation into DNA
• Uses – in combination with other
antiretrovirals for HIV-1 suppression
89. Adefovir
• An analog of adenosine monophosphate
• Phosphorylated by cellular kinases
• M.O.A. - Competitively inhibits HBV DNA
polymerase and results in chain termination
after incorporation into viral DNA
• Uses - Hepatitis B
• Side effects - nephrotoxicity
91. Interferons
• Interferon Alfa
• Endogenous proteins
• induce host cell enzymes that inhibit viral RNA translation
and cause degradation of viral mRNA and tRNA
• Bind to membrane receptors on cell surface
• May also inhibit viral penetration, uncoating, mRNA
synthesis, and translation, and virion assembly and release
www.freelivedoctor.com
92. Interferons
• Pegylated interferon Alfa
• A linear or branced polyethylene gylcol (PEG)
moiety is attached to covalently to interferon
• Increased half-life and steady drug
concentrations
• Less frequent dosing
• Tx chronic hepatitis C in combination with
ribavirin
www.freelivedoctor.com
93. Ribavirin
• A guanosine analog
• phosphorylated intracellularly by host
enzymes
• inhibits capping of viral messenger RNA
• inhibits the viral RNA-dependent RNA
polymerase
• inhibits replication of DNA and RNA viruses
www.freelivedoctor.com
96. Amantadine and Rimantadine
– cyclic amines
– inhibit the uncoating of viral RNA therefore
inhibiting replication
– resistance due to mutations in the RNA
sequence coding for the structural M2
protein
– used in the prevention and treatment of
Influenza A
www.freelivedoctor.com
97. Zanamivir and Oseltamivir
• Inhibits the enzyme neuraminidase
• inhibit the replication of influenza A and
Influenza B
• treats uncomplicated influenza infections
• administered intranasally
www.freelivedoctor.com
98. Antivirals: Nursing Implications
• Before beginning therapy, thoroughly
assess underlying disease and medical history,
including allergies.
• Assess baseline VS and nutritional status.
• Assess for contraindications, conditions
that may indicate cautious use, and potential drug
interactions.
99. Antivirals: Nursing Implications
• Be sure to teach proper application technique for ointments,
aerosol
powders, etc.
• Emphasize hand washing before and after administration of
medications to prevent site contamination and spread of
infection.
• Patients should wear a glove or finger cot when applying
ointments or solutions to affected areas.
100. Antivirals: Nursing Implications
• Instruct patients to consult their physician before
taking any other medication, including OTC
medications.
• Emphasize the importance of good hygiene.
• Inform patients that antiviral agents are not cures,
but do help to manage symptoms.
101. Antivirals: Nursing Implications
• Instruct patients on the importance of taking these
medications exactly as prescribed and for the full course
of treatment.
• With zidovudine:
• Inform patients that hair loss MAY occur so that they are
prepared for this rare adverse reaction.
• This medication should be taken on an empty stomach.
103. Antivirals: Nursing Implications
Monitor for therapeutic effects:
• effects will vary depending on the type of viral infection
• Effects range from delayed progression of AIDS
and ARC to decrease in flu-like symptoms, decreased
frequency of herpes-like flare-ups,
or crusting over of herpetic lesions.
105. • Fungi
– Also known as mycoses
– Very large and diverse group of microorganisms
– Broken down into yeasts and molds
106. • Yeasts
– Single-cell fungi
– Reproduce by budding
– Very useful organisms
• Baking
• Alcoholic beverages
107. • Molds
– Multicellular
– Characterized by long, branching filaments called
hyphae
108. • Mycotic Infections
– Four General Types
– Cutaneous
– Subcutaneous
– Superficial
– Systemic*
• *Can be life-threatening
• *Usually occur in immunocompromised host
109. • Mycotic Infections
– Candida albicans
– Due to antibiotic therapy, antineoplastics, or
immunosuppressants
– May result in overgrowth and systemic infections
110. • Mycotic Infections
– In the mouth:
– Oral candidiasis or thrush
– Newborn infants and immunocompromised
patients
113. • Antifungal Agents
– Broken down into four major groups based on
their chemical structure
– Polyenes: amphotericin B and nystatin
– Flucytosine
– Imidazoles: ketoconazole, miconazole,
clotrimazole, fluconazole
– Griseofulvin
114. • Antifungal Agents: Mechanism of Action
– Polyenes: amphotericin B and nystatin
– Bind to sterols in cell membrane lining
– Allow K+ & Mg++ to leak out, altering fungal cell
metabolism
– Result: fungal cell death
115. • Antifungal Agents: Mechanism of Action
– flucytosine
– Also known as 5-fluorocytosine (antimetabolite)
– Taken up by fungal cells and interferes with DNA synthesis
– Result: fungal cell death
• Antifungal Agents: Mechanism of Action
– Imidazoles ketoconazole, miconazole, clotrimazole,
fluconazole
– Inhibit an enzyme, resulting in cell membrane leaking
– Lead to altered cell membrane
– Result: fungal cell death
119. • Antifungal Agents: Nursing Implications
– Before beginning therapy, assess for
hypersensitivity, possible contraindications, and
conditions that require cautious use.
– Obtain baseline VS, CBC, liver function studies,
and ECG.
– Assess for other medications used (prescribed and
OTC) in order to avoid drug interactions.
120. • Antifungal Agents: Nursing Implications
– Follow manufacturer’s directions carefully for
reconstitution and administration.
– Monitor VS of patients receiving IV infusions every
15 to 30 minutes.
– During IV infusions, monitor I & O and urinalysis
findings to identify adverse renal effects.
121. • Antifungal Agents: Nursing Implications
– amphotericin B
– To reduce the severity of the infusion-related
reactions, pretreatment with an antipyretic
(acetaminophen), antihistamines, and antiemetics
may be given.
– A test dose of 1 mg per 20 mL 5% dextrose in
water infused over 30 minutes should be given.
– Use IV infusion pumps and the most distal veins
possible.
122. • Antifungal Agents: Nursing Implications
– Tissue extravasation of fluconazole at the IV site
may lead to tissue necrosis—monitor IV site
carefully.
– Oral forms of griseofulvin should be given with
meals to decrease GI upset.
– Monitor carefully for side/adverse effects.
123. • Antifungal Agents: Nursing Implications
– Monitor for therapeutic effects:
– Easing of the symptoms of infection
– Improved energy levels
– Normal vital signs, including temperature
124. ANTIHELMINTHIC
• Antihelmintics
• Drugs used to treat parasitic worm infections:
helmintic infections
• Unlike protozoa, helminths are large and have
complex cellular structures
• Drug treatment is very specific
125. • Antihelmintics
• It is VERY IMPORTANT to identify the causative
worm
• Done by finding the parasite ova or larvae in
feces, urine, blood, sputum, or tissue
– cestodes (tapeworms)
– nematodes (roundworms)
– trematodes (flukes)
126. • Antihelmintics: Mechanism of Action and Uses
• diethylcarbamazine (Hetrazan)
• Inhibits rate of embryogenesis
• thiabendazole (Mintezol)
• Inhibits the helminth-specific enzyme,
fumarate reductase
– Both used for nematodes (tissue and some
roundworms)
127. • Antihelmintics: Mechanism of Action
• piperazine (Vermizine) and pyrantel
(Antiminth)
• Blocks acetylcholine at the neuromuscular
junction, resulting in paralysis of the worms,
which are then expelled through the GI tract
– Used to treat nematodes (giant worm and
pinworm)
128. • Antihelmintics: Mechanism of Action
• mebendazole (Vermox)
• Inhibits uptake of glucose and other nutrients,
leading to autolysis and death of the parasitic
worm
– Used to treat cestodes and nematodes
129. • Antihelmintics: Mechanism of Action
• niclosamide (Niclocide)
• Causes the worm to become dislodged from
the GI wall
• They are then digested in the intestines and
expelled
– Used to treat cestodes
130. • Antihelmintics: Mechanism of Action
• oxamniquine (Vansil) and praziquantel (Biltricide)
• Cause paralysis of worms’ musculature and
immobilization of their suckers
• Cause worms to dislodge from mesenteric veins
to the liver, then killed by host tissue reactions
– Used to treat trematodes, cestodes (praziquantel
only)
132. ANTIPROTOZOALs
• Protozoal Infections
• Parasitic protozoa: live in or on humans
• malaria
• leishmaniasis
• amebiasis
• giardiasis
• trichomoniasis
133. Malaria
• Caused by the plasmodium protozoa.
• Four different plasmodium species.
• Cause: the bite of an infected adult mosquito.
• Can also be transmitted by infected individuals
via blood transfusion, congenitally, or via
infected needles by drug abusers.
134. Malarial Parasite (plasmodium)
• Two Interdependent Life Cycles
• Sexual cycle: in the mosquito
• Asexual cycle: in the human
– Knowledge of the life cycles is essential in
understanding antimalarial drug treatment.
– Drugs are only effective during the asexual cycle.
135. Plasmodium Life Cycle
• Asexual cycle: two phases
• Exoerythrocytic phase: occurs “outside” the
erythrocyte
• Erythrocytic phase: occurs “inside” the
erythrocyte
– Erythrocytes = RBCs
136. Antimalarial Agents
• Attack the parasite during the asexual phase,
when it is vulnerable
• Erythrocytic phase drugs: chloroquine,
hydroxychloroquine, quinine, mefloquine
• Exoerythrocytic phase drug: primaquine
• May be used together for synergistic or
additive killing power.
137. Antimalarials: Mechanism of Action
• 4-aminoquinoline derivatives chloroquine and
hydroxychloroquine
• Bind to parasite nucleoproteins and interfere
with protein synthesis.
• Prevent vital parasite-sustaining substances
from being formed.
• Alter pH within the parasite.
• Interfere with parasite’s ability to metabolize
and use erythrocyte hemoglobin.
• Effective only during the erythrocytic phase
138. Antimalarials: Mechanism of Action
• 4-aminoquinoline derivatives quinine and
mefloquine
• Alter pH within the parasite.
• Interfere with parasite’s ability to metabolize
and use erythrocyte hemoglobin.
• Effective only during the erythrocytic phase.
139. Antimalarials: Mechanism of Action
• diaminophyrimidines pyrimethamine and
trimethoprim
• Inhibit dihydrofolate reductase in the parasite.
• This enzyme is needed by the parasite to make
essential substances.
• Also blocks the synthesis of tetrahydrofolate.
• These agents may be used with sulfadoxine or
dapsone for synergistic effects.
140. Antimalarials: Mechanism of Action
• primaquine
• Only exoerythrocytic drug.
• Binds and alters DNA.
• sulfonamides, tetracyclines, clindamycin
• Used in combination with antimalarials to
increase protozoacidal effects
141. Antimalarials: Drug Effects
• Kill parasitic organisms.
• Chloroquine and hydroxychloroquine also
have antiinflammatory effects.
142. Antimalarials: Therapeutic Uses
• Used to kill plasmodium organisms, the
parasites that cause malaria.
• The drugs have varying effectiveness on the
different malaria organisms.
• Some agents are used for prophylaxis against
malaria.
• Chloroquine is also used for rheumatoid
arthritis and lupus.
143. Antimalarials: Side Effects
• Many side effects for the various agents
• Primarily gastrointestinal: nausea, vomiting,
diarrhea, anorexia, and abdominal pain
146. Protozoal Infections
• Transmission
• Person-to-person
• Ingestion of contaminated water or food
• Direct contact with the parasite
• Insect bite (mosquito or tick)
147. Antiprotozoals: Mechanism of Action
and Uses
• atovaquone (Mepron)
• Protozoal energy comes from the
mitochondria
• Atovaquone: selective inhibition of
mitochondrial electron transport
• Result: no energy, leading to cellular death
– Used to treat mild to moderate P. carinii
148. Antiprotozoals: Mechanism of Action
and Uses
metronidazole
• Disruption of DNA synthesis as well as nucleic
acid synthesis
• Bactericidal, amebicidal, trichomonacidal
– Used for treatment of trichomoniasis, amebiasis,
giardiasis, anaerobic infections, and antibiotic-
associated pseudomembranous colitis
149. Antiprotozoals: Mechanism of Action
and Uses
pentamidine
• Inhibits DNA and RNA
• Binds to and aggregates ribosomes
• Directly lethal to Pneumocystis carinii
• Inhibits glucose metabolism, protein and RNA
synthesis, and intracellular amino acid
transport
– Mainly used to treat P. carinii pneumonia and
other protozoal infections
150. Antiprotozoals: Mechanism of Action
and Uses
iodoquinol (Yodoxin, Di-Quinol)
• “ Luminal” or “contact” amebicide
• Acts primarily in the intestinal lumen of the
infected host
• Directly kills the protozoa
– Used to treat intestinal amebiasis
151. Antiprotozoals: Mechanism of Action
and Uses
paromomycin
• “Luminal” or “contact” amebicide
• Kills by inhibiting protein synthesis
– Used to treat amebiasis and intestinal protozoal
infections, and also adjunct therapy in
management of hepatic coma
154. • Antimalarial, Antiprotozoal, Antihelmintic
Agents: Nursing Implications
• Before beginning therapy, perform a thorough
health history and medication history, and
assess for allergies.
• Check baseline VS.
• Check for conditions that may contraindicate
use, and for potential drug interactions.
155. • Antimalarial, Antiprotozoal, Antihelmintic Agents:
Nursing Implications
• Some agents may cause the urine to have an
asparagus-like odor, or cause an unusual skin
odor, or a metallic taste; be sure to warn the
patient ahead of time.
• Administer ALL agents as ordered and for the
prescribed length of time.
• Most agents should be taken with food to reduce
GI upset.
156. • Antimalarial Agents: Nursing Implications
• Assess for presence of malarial symptoms.
• When used for prophylaxis, these agents
should be started 2 weeks before potential
exposure to malaria, and for 8 weeks after
leaving the area.
• Medications are taken weekly, with 8 ounces
of water.
157. • Antimalarial Agents: Nursing Implications
• Instruct patient to notify physician
immediately if ringing in the ears, hearing
decrease, visual difficulties, nausea, vomiting,
profuse diarrhea, or abdominal pain occur.
• Alert patients to the possible recurrence of
the symptoms of malaria so that they will
know to seek immediate treatment.
158. • Antimalarial, Antiprotozoal, Antihelmintic
Agents: Nursing Implications
• Monitor for side effects:
• Ensure that patients know the side effects that
should be reported.
• Monitor for therapeutic effects and adverse
effects with long-term therapy.
