ppt chapter 40

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 40

Antibiotics Affecting Protein Synthesis

Chapter 40

Antibiotics Affecting Protein Synthesis


Physiology 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 SynthesisProtein Synthesis


Aminoglycosides 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 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.)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 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 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.


Gentamicin: Nursing Diagnoses and Outcomes (cont.)Gentamicin: Nursing Diagnoses and 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

– Desired outcome: The patient will remain free of injury and contact the provider if confusion, disorientation, or depression occurs.


Gentamicin: Nursing Diagnoses and Outcomes (cont.)Gentamicin: Nursing Diagnoses and 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 InterventionsGentamicin: 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 EvaluationsGentamicin: 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.


QuestionQuestion

• 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


AnswerAnswer

• 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 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 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.)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 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



Clindamycin: Nursing Diagnoses and Outcomes 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.)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 InterventionsClindamycin: 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 EvaluationsClindamycin: 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.


QuestionQuestion

• What is the most serious adverse reaction of clindamycin administration?

– A. Respiratory arrest

– B. Pseudomembranous colitis

– C. Ventricular tachycardia

– D. Ototoxicity


AnswerAnswer

• 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 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 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.)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 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 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 InterventionsErythromycin: 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 EvaluationsErythromycin: 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.


QuestionQuestion

• Grapefruit juice will decrease the serum concentration of erythromycin.

– A. True

– B. False


AnswerAnswer

• 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

• 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 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.)Linezolid: Core Drug Knowledge (cont.)


– Hypersensitivity

• Adverse effects

– Diarrhea, headache, nausea, and vomiting


– Adrenergic and serotonergic agents


Linezolid: Core Patient Variables Linezolid: Core Patient Variables

• Health status

– Assess medical history.


– Pregnancy Category C drug


– Evaluate diet and alcohol use.

• Environment



Linezolid: Nursing Diagnoses and Outcomes 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.)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 InterventionsLinezolid: 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 EvaluationsLinezolid: 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.


QuestionQuestion

• Linezolid is classified as a Pregnancy Category ___ drug.

– A. A

– B. B

– C. C

– D. D

– E. X


AnswerAnswer

• C. C

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


Streptogramins 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 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.)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 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 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.)Quinupristin/Dalfopristin: Nursing Diagnoses and Outcomes (cont.)

• Risk for Injury related to potential superinfection or hepatotoxicity

– Desired outcome: The patient will remain free of 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 InterventionsQuinupristin/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 EvaluationsQuinupristin/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.


QuestionQuestion

• Quinupristin/dalfopristin is best administrated via

– A. Oral route

– B. PICC line

– C. Peripheral IV

– D. Z-track IM


AnswerAnswer

• 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 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 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.)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 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 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.)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 InterventionsTetracycline: 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 EvaluationsTetracycline: 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.


QuestionQuestion

• Tetracycline should not be administered with antacids.

– A. True

– B. False


AnswerAnswer

• 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 that Affect Protein Synthesis

• Miscellaneous antibiotics include chloramphenicol and spectinomycin.

• Used to treat large outbreaks of typhus

• Prototype: chloramphenicol


Chloramphenicol: Core Drug Knowledge 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.)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 Chloramphenicol: Core Patient Variables

• Health status

– Assess medical history.


– Assess pregnancy status.

• Environment



Chloramphenicol: Nursing Diagnoses and Outcomes 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 InterventionsChloramphenicol: 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 EvaluationsChloramphenicol: 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.


QuestionQuestion

• A serious and potentially life-threatening adverse effect of chloramphenicol is “gray baby” syndrome.

– A. True

– B. False


AnswerAnswer

• 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.

ppt chapter 40

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