Ppt chapter 40

Chapter 40
Antibiotics Affecting Protein
Synthesis
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Physiology
• In all cells, the process of protein synthesis is divided
into two sections: transcription and translation.
• Initially, transcription occurs within the nucleus,
producing messenger ribonucleic acid (mRNA).
• This mRNA migrates from the nucleus to the cytoplasm.
During this step, mRNA goes through different types of
maturation, including one called splicing, during which
the noncoding sequences are eliminated.
• Translation occurs in the cytoplasm.

Protein Synthesis

Aminoglycosides
• The aminoglycosides have been in use since 1944.
• They are extremely effective antibiotics for treating
severe infections.
• However, their general use is limited because of the
potential for serious adverse effects.
• Prototype drug: gentamicin

Gentamicin: Core Drug Knowledge
• Pharmacotherapeutics
– Serious infections
• Pharmacokinetics
– Distribution: throughout the body except CS; higher
concentration in kidneys than serum
• Pharmacodynamics
– Entering the bacterial cell and binding to the 30S
ribosomal subunit

Gentamicin: Core Drug Knowledge (cont.)
• Contraindications and precautions
– Hypersensitivity, pregnancy and lactation
• Adverse effects
– Neurotoxicity, nephrotoxicity, ototoxicity, and
neuromuscular blockade
• Drug interactions
– Acyclovir, amphotericin B, cephalothin, cisplatin,
cyclosporine, loop diuretics, prostaglandin synthetase
inhibitors, and vancomycin

Gentamicin: Core Patient Variables
• Health status
– Past medical and any kidney problems
• Life span and gender
– Ototoxic to the fetus, assess pregnancy status.
• Lifestyle, diet, and habits
– Assess the nutritional status of the patient.
• Environment
– Assess the environment where the drug will be
given.

Gentamicin: Nursing Diagnoses and
Outcomes
• Risk for Injury related to potential drug-related allergic
reactions or neuromuscular blockade or suppression of
bone marrow function
– Desired outcome: The patient will remain free of
injury and will contact the prescriber if unusual
adverse effects occur.
• Diarrhea related to drug effects
– Desired outcome: The patient will avoid
dehydration, maintain fluid intake, and contact the
prescriber if diarrhea persists.

Outcomes (cont.)
• Imbalanced Nutrition: Less than Body Requirements,
related to drug-induced GI effects or superinfection
– Desired outcome: The patient will maintain body
weight and report any persistent adverse effect.
• Risk for Injury related to CNS effects
injury and contact the provider if confusion,
disorientation, or depression occurs.

Outcomes (cont.)
• Disturbed Sensory Perception related to potential
ototoxicity
– Desired outcome: The patient will report sensory or
perceptual changes to the prescriber.
• Excess Fluid Volume related to potential nephrotoxicity
– Desired outcome: The patient will report any
weight gain exceeding 3 lb to the health care
prescriber.

Gentamicin: Planning and Interventions
• Maximizing therapeutic effects
– Make sure that patients receive the full course as
prescribed at around-the-clock intervals.
– Do not give at the same time as extended penicillin.
• Minimizing adverse effects
– Maintain blood levels of gentamicin within a
therapeutic margin that is very narrow.
– Monitor for signs of ototoxicity and nephrotoxicity.

Gentamicin: Teaching, Assessment, and
Evaluations
• Patient and family education
– Patients should not take the drug if pregnant or
breast-feeding.
– Teach patients how to identify, report, and manage
signs and symptoms of allergic reaction and adverse
effects.
• Ongoing assessment and evaluation
– Coordinate the care of the patient to ensure that
other potentially nephrotoxic or ototoxic drugs are
not added to the treatment plan.

Question
• Gentamicin is effective against which of the following
organism(s)?
– A. Pseudomonas aeruginosa
– B. Proteus mirabilis
– C. Klebsiella
– D. Enterobacter
– E. All of the above

Answer
• E. All of the above
• Rationale: Gentamicin is effective in managing
infections caused by gram-negative bacilli.
• Susceptible organisms include Pseudomonas
aeruginosa, Proteus mirabilis, Escherichia coli;
Klebsiella, Enterobacter, Serratia, and Citrobacter
species; and staphylococci.

Lincosamides
• They are very toxic drugs.
• Their use must be monitored and limited to situations
with infections by bacteria with known sensitivity.
• Prototype drug: clindamycin (Cleocin)

Clindamycin: Core Drug Knowledge
– Aerobic gram-positive cocci and several anaerobic
gram-negative and gram-positive organisms
– Varies with route of administration. Metabolized:
liver. Excreted: bile and urine.
– Enters the bacterial cell and binds to bacterial
ribosomes, suppressing protein synthesis

Clindamycin: Core Drug Knowledge
(cont.)
– Hypersensitivity, pregnancy, and lactation
• Adverse effects
– Pseudomembranous colitis, maculopapular rash,
erythema, and pruritus
– Neuromuscular blockers, aluminum salts,
cyclosporine, benzoyl peroxide, tretinoin, and
salicylic acid

Clindamycin: Core Patient Variables
• Health status
– Assess for allergy to medication.
– Assess the growth and developmental level of the
child or infant.
– Assess lifestyle to ensure that the drug will be given
properly.
• Environment
– Assess the environment where the drug will be given.

Clindamycin: Nursing Diagnoses and
Outcomes
• Risk for Injury related to allergic reactions
– Desired outcome: The patient will stop drug
therapy and immediately report symptoms of allergic
reaction to the prescriber.
• Diarrhea related to drug effects
– Desired outcome: The patient will avoid
dehydration and report persistent diarrhea to the
provider.

Clindamycin: Nursing Diagnoses and
Outcomes (cont.)
• Imbalanced nutrition: Less than Body Requirements,
related to drug-related GI effects, alteration in taste,
superinfections
– Desired outcome: The patient will maintain body
weight and report persistent symptoms affecting
nutritional status.
• Risk for Injury related to possible blood dyscrasias
– Desired outcome: The patient will remain injury-free
throughout drug therapy.

Clindamycin: Planning and Interventions
– Make sure that the patient receives the full course of
clindamycin as prescribed.
– Coordinate the administration of drugs to decrease
potential undesired interactions.
– Clindamycin should be administered on an empty
stomach with a full glass of water.
– Report diarrhea to the provider immediately.

Clindamycin: Teaching, Assessment, and
Evaluations
– Advise patients to contact the prescriber immediately
if they experience diarrhea.
– Teach patients to recognize and report symptoms of
allergic reaction and superinfection.
– Monitor the patient for the onset of diarrhea.

Question
• What is the most serious adverse reaction of clindamycin
administration?
– A. Respiratory arrest
– B. Pseudomembranous colitis
– C. Ventricular tachycardia
– D. Ototoxicity

Answer
• B. Pseudomembranous colitis
• Rationale: Pseudomembranous colitis is the most
serious side effect of clindamycin and carries a Black
Box warning because of this side effect.

Macrolide Antibiotics
• The macrolide antibiotics have been in use since 1952.
• They are characterized by molecules made up of large-ring
lactones.
• Macrolides are bacteriostatic or bactericidal in susceptible
bacteria.
• Prototype drug: erythromycin

Erythromycin: Core Drug Knowledge
– Treating Legionnaire disease, Mycoplasma
pneumoniae pneumonia, diphtheria, chlamydial
infections, and chancroid
– The drug is easily inactivated by gastric acid. Peak 1
to 4 hours. Metabolized: liver. Excreted: urine and
bile.
– Inhibiting RNA-dependent protein synthesis at the
chain elongation step

Erythromycin: Core Drug Knowledge
(cont.)
– Allergy to medication
• Adverse effects
– GI symptoms, urticaria, maculopapular rash,
erythema, and interstitial nephritis
– Astemizole and terfenadine

Erythromycin: Core Patient Variables
• Health status
– Assess medical history and allergies.
– Assess pregnancy and lactation status.
– Instruct how to take the medication to avoid toxicity.
• Environment

Erythromycin: Nursing Diagnoses and
Outcomes
• Risk for Injury related to possible allergic reactions
– Desired outcome: The patient will stop drug therapy and
report any signs of allergic reaction immediately to the
prescriber.
• Diarrhea related to drug-induced GI upset
– Desired outcome: The patient will avoid dehydration,
maintain fluid intake, and contact the prescriber if
diarrhea persists.
• Risk for Infection related to potential for superinfection
following drug therapy
– Desired outcome: The patient will contact the provider if
any signs of superinfection occur, for example, sore throat
or fever.

Erythromycin: Planning and Interventions
– Reconstitute erythromycin with sterile water only.
– Prepared infusion solutions that are stored at room
temperature must be used within 8 hours.
– Because erythromycin can be very irritating to veins,
it is important to administer IV infusions over 30 to
60 minutes.

Erythromycin: Teaching, Assessment, and
Evaluations
– Encourage patients to take the complete course of
antibiotics.
– Advise patients to take erythromycin on an empty
stomach, unless GI distress is unbearable.
– Monitor for signs of allergic reactions, resolution of
presenting signs and symptoms of infection, and
signs of superinfection.

Question
• Grapefruit juice will decrease the serum concentration of
erythromycin.
– A. True
– B. False

Answer
• B. False
• Rationale: Instruct the patient to avoid grapefruit or
grapefruit juice because it increases the serum
concentration of erythromycin and may cause adverse
effects or toxicity.

Oxazolidinones
• Oxazolidinones are the first new class of antibiotics
developed specifically for treating methicillin-resistant
Staphylococcus aureus (MRSA) infections.
• Prototype drug: linezolid (Zyvox)

Linezolid: Core Drug Knowledge
– Treatment of VRE and MRSA
– Administered: oral or IV. Metabolism: liver. Excreted:
kidneys.
– Blocking the early stages of the process bacteria use
to make proteins

Linezolid: Core Drug Knowledge (cont.)
– Hypersensitivity
• Adverse effects
– Diarrhea, headache, nausea, and vomiting
– Adrenergic and serotonergic agents

Linezolid: Core Patient Variables
• Health status
– Assess medical history.
– Pregnancy Category C drug
– Evaluate diet and alcohol use.
• Environment

Linezolid: Nursing Diagnoses and
Outcomes
• Deficient Fluid Volume related to nausea, vomiting, and
diarrhea from linezolid therapy
– Desired outcome: The patient will remain well
hydrated throughout therapy.
• Risk for Injury related to thrombocytopenia and
pseudomembranous colitis
– Desired outcome: The patient will remain free
from injury and contact the health care provider
immediately if any signs of bleeding or abdominal
pain occur.

Linezolid: Nursing Diagnoses and
Outcomes (cont.)
• Risk for Injury related to hypertensive crisis
– Desired outcome: The patient will remain
normotensive by adhering to antihypertensive
therapy and limiting foods or beverages with
tyramine, caffeine, or alcohol.

Linezolid: Planning and Interventions
– Administer at evenly spaced intervals.
– To avoid hypertensive crisis, monitor the patient’s
intake of food or beverages containing tyramine,
caffeine, or alcohol.
– Serial blood pressure readings should be obtained
throughout therapy.

Linezolid: Teaching, Assessment, and
Evaluations
– Explain dietary restrictions, focusing on food or
beverages containing tyramine, caffeine, or alcohol.
– Teach patients the signs and symptoms of
thrombocytopenia and pseudomembranous colitis.
– Monitor for efficacy of treatment and resolution of
the presenting infection.

Question
• Linezolid is classified as a Pregnancy Category ___ drug.
– A. A
– B. B
– C. C
– D. D
– E. X

Answer
• C. C
• Rationale: Linezolid is classified as a pregnancy category
C drug.

Streptogramins
• Streptogramins are the newest class of antibiotics.
• Designed to eradicate “superbugs” resistant to other
antibiotics.
• Prototype drug: quinupristin/dalfopristin (Synercid)

Quinupristin/Dalfopristin: Core Drug
Knowledge
– Serious or life-threatening infections associated with
VRE
– Administered: IV. T½: 1 hour.
– Inhibits bacterial protein synthesis by irreversibly
blocking ribosome functioning

Quinupristin/Dalfopristin: Core Drug
Knowledge (cont.)
– Hypersensitivity
• Adverse effects
– Pseudomembranous colitis, superinfection, and
hepatotoxicity
– Drugs that are metabolized by CYP3A4, a cytochrome
of P-450

Quinupristin/Dalfopristin: Core Patient
Variables
• Health status
– Assess health history and contraindications to
medication use.
– Pregnancy Category B drug
• Environment

Quinupristin/Dalfopristin: Nursing
Diagnoses and Outcomes
• Pain related to IV administration
– Desired outcome: The patient will inform you
immediately should pain at the injection site occur.
• Diarrhea related to potential pseudomembranous colitis
– Desired outcome: The patient will remain well
hydrated throughout therapy and report any diarrhea
immediately.

Quinupristin/Dalfopristin: Nursing
Diagnoses and Outcomes (cont.)
• Risk for Injury related to potential superinfection or
hepatotoxicity
injury throughout therapy.
• Risk for Impaired Skin Integrity related to rash or
pruritus.
– Desired outcome: The patient will report itching or
rash immediately to minimize potential for infection.

Quinupristin/Dalfopristin: Planning and
Interventions
– The medication should not be administered with any
other medications through a Y-site infusion.
– Flush the line before and after administration with
5% dextrose and water.
– Administer these drugs in a peripherally inserted
central catheter (PICC) or a central line whenever
possible.

Quinupristin/Dalfopristin: Teaching,
Assessment, and Evaluations
– Teach patients the potential adverse effects.
– Advise patients to report any diarrhea immediately.
– During infusion, monitor the IV site for signs of
infiltration, edema, or phlebitis.
– Question the patient regarding pain at the injection
site.

Question
• Quinupristin/dalfopristin is best administrated via
– A. Oral route
– B. PICC line
– C. Peripheral IV
– D. Z-track IM

Answer
• B. PICC line
• Rationale: Because injection site problems are very
common with the administration of
quinupristin/dalfopristin, administer these drugs in a
peripherally inserted central catheter (PICC) line
whenever possible.

Tetracyclines
• The tetracyclines were developed as semisynthetic
antibiotics based on the structure of a common soil mold.
• They are broad-spectrum antibiotics that affect both
gram-positive and gram-negative bacteria.
• Over the years, major resistance has developed to
tetracyclines.
• Prototype drug: tetracycline

Tetracycline: Core Drug Knowledge
– Rickettsia species, Mycoplasma pneumoniae, and
Chlamydia trachomatis
– Administered: oral. Excreted: kidneys.
– Inhibits or retards the growth of bacteria but does
not kill them

Tetracycline: Core Drug Knowledge
(cont.)
– Allergy, pregnancy, or lactation
• Adverse effects
– GI upset, photosensitivity, and rash
– Penicillin G, aluminum, bismuth, calcium, iron,
magnesium, and zinc salts

Tetracycline: Core Patient Variables
• Health status
– Assess medical status.
– Pregnancy Category D drug
– Assess dietary intake.
• Environment
– Assess for exposure to sun.

Tetracycline: Nursing Diagnoses and
Outcomes
• Risk for Injury related to potential superinfection or
allergic drug reaction
– Desired outcome: The patient will experience no
new infection and no preventable allergic reaction
related to tetracycline.
• Diarrhea related to drug-induced GI effects
– Desired outcome: The patient will report any
incidence of diarrhea and follow the prescriber’s
recommendation.

Tetracycline: Nursing Diagnoses and
Outcomes (cont.)
• Imbalanced nutrition: Less than Body Requirements,
related to adverse GI effects of nausea, vomiting,
diarrhea, and altered taste
– Desired outcome: The patient will maintain dietary
intake to provide adequate nutrition.
• Risk for Impaired Skin Integrity related to drug-induced
photosensitivity
– Desired outcome: The patient will dress
appropriately and take adequate precautionary
measures while outdoors to avoid unnecessary
sunburn.

Tetracycline: Planning and Interventions
– To maximize absorption, oral preparations should be
administered on an empty stomach either 1 hour
before or 2 hours after any meals or other drugs.
– Monitor the patient to ensure that adequate fluids are
given to replace fluid lost with diarrhea.
– Wear protective clothing and sunscreen when
outdoors.

Tetracycline: Teaching, Assessment, and
Evaluations
– Advise women of childbearing age that tetracycline
should not be taken during pregnancy or breast-feeding.
– Advise patients to take tetracycline on an empty
stomach.
– Monitor renal status to detect and prevent
hepatotoxicity and to observe for any signs of
superinfection.

Question
• Tetracycline should not be administered with antacids.
– A. True
– B. False

Answer
• A. True
• Rationale: Tetracycline forms an insoluble chelate with
aluminum, bismuth, calcium, iron, magnesium, and zinc
salts, which are frequently an ingredient in antacids.

Miscellaneous Antibiotics that Affect
Protein Synthesis
• Miscellaneous antibiotics include chloramphenicol and
spectinomycin.
• Used to treat large outbreaks of typhus
• Prototype: chloramphenicol

Chloramphenicol: Core Drug Knowledge
– True broad-spectrum antibiotic
– Administered: oral and IV. Peak 1 to 3 hours.
– Inhibiting the protein synthesis of bacterial cells

Chloramphenicol: Core Drug Knowledge
(cont.)
– Toxic reaction to the medication
• Adverse effects
– Aplastic anemia, hypoplastic anemia,
thrombocytopenia, pancytopenia, and
granulocytopenia
– Many different types of drugs

Chloramphenicol: Core Patient Variables
• Health status
– Assess medical history.
– Assess pregnancy status.
• Environment

Chloramphenicol: Nursing Diagnoses and
Outcomes
• Risk for Injury related to drug-induced adverse effects,
such as blood dyscrasias, gray baby syndrome, and CNS
effects, including optic or peripheral neuritis, headache,
depression, confusion, or delirium
– Desired outcome: Regular and careful monitoring
will protect the patient from permanent drug-related
adverse effects.
• Risk for Impaired Skin Integrity, rash and pruritus,
related to topical drug use
– Desired outcome: The nurse and patient will
observe for and report signs of unusual skin reaction
and contact the prescriber.

Chloramphenicol: Planning and
Interventions
– Oral chloramphenicol should be administered on an
empty stomach 1 hour before or 2 hours after meals.
– Monitor plasma concentrations at least weekly or
more often in patients with hepatic or renal
impairment.

Chloramphenicol: Teaching, Assessment,
and Evaluations
– Explain the importance of completing therapy.
– Teach patients the importance of measuring fluid
intake and output accurately.
– For patients receiving systemic therapy, coordinate
serial monitoring of chloramphenicol plasma
concentrations.

Question
• A serious and potentially life-threatening adverse effect
of chloramphenicol is “gray baby” syndrome.
– A. True
– B. False

Answer
• A. True
• Rationale: “Gray baby” syndrome is most common in
premature infants or newborns receiving
chloramphenicol, whose hepatic systems have
difficulty conjugating or excreting chloramphenicol.

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