Transcript Roach: Introduction to Clinical Pharmacology

Introductory Clinical Pharmacology
Chapter 9
Tetracyclines, Macrolides, and
Lincosamides
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Tetracyclines (TCN)
• Anti-infectives composed of natural and
semisynthetic compounds
• Actions: Inhibit bacterial protein synthesis
• Used as broad spectrum antibiotic when penicillin is
contraindicated
• Treats infections
– caused by rickettsiae
– skin and soft tissue
– uncomplicated urethral, rectal infections
– Helicobacter pylori
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Tetracyclines: Adverse reactions
• Gastrointestinal/other body system reactions
– Nausea and or vomiting
– Diarrhea
– Epigastric distress
– Stomatitis
– Sore throat
– Skin rashes
– Photosensitivity reaction
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EXAMPLES OF TCNs
• Sumycin / tetracycline
• Vibramycin / doxycycline
• Minocin / minocycline
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Tetracyclines: Contraindications
• Contraindicated in patients
with hypersensitivity or during
pregnancy, lactation (Category
D)
• Nursing alert
– Not given to children
younger than 9 years of
age (may cause
yellow/gray/brown
discoloration on developing
teeth)
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Tetracyclines: Precautions
• Used cautiously in patients with:
– Impaired renal function
– Liver impairment
• Chronic care alert
– May increase the risk of digitalis toxicity
in patients who take digitalis drugs for
heart disease
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Tetracyclines: Interactions
Interactant drug
Effect of interaction
Antacids containing
aluminum, zinc,
magnesium, or bismuth
salts
Decreases
effectiveness of
tetracyclines
Oral anticoagulants
Increases risk for
bleeding
Decreases
effectiveness of
contraceptive agent
Oral contraceptives
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Tetracyclines: Interactions (cont’d)
Interactant drug
Effect of interaction
Digoxin
Increases the risk
for digitalis toxicity
Calcium-rich foods
Causes potentially
impaired absorption
of tetracycline
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Macrolides
• Effective against a wide variety of
pathogenic organisms, particularly infections
of the respiratory and genitourinary tracts
• Act by causing changes in protein function
and synthesis
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Examples of Macrolides
• Zithromax/azithromycin
• Biaxin / clarithromycin
• E-mycin , E.E.S / erythromycin
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Macrolides: Uses
• Used as prophylaxis before dental or other
procedures in patients allergic to penicillin
and in the treatment of:
– A wide range of gram-negative and
gram-positive infections
– Acne vulgaris and skin infections
– Upper respiratory infections caused by
Hemophilus influenza
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Adverse Reactions of Macrolides
• Gastrointestinal (GI)
– Nausea
– Vomiting
– Diarrhea
– Abdominal pain or cramping
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Macrolides: Contraindications and
Precautions
• Contraindicated in patients with
hypersensitivity to the macrolides;
preexisting liver disease
• Used cautiously in patients with liver
dysfunction; during pregnancy or lactation
(pregnancy categories B and C)
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Macrolides: Interactions
Interactant drug
Effect of interaction
Antacids (kaolin,
aluminum salts, or
magaldrate)
Decreases absorption
and effectiveness of
macrolide
Digoxin
Increases serum levels
of digoxin
Increases risk of
bleeding
Anticoagulants
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Macrolides: Interactions (cont’d)
Interactant drug
Effect of interaction
Clindamycin, lincomycin, Decreases
or chloramphenicol
therapeutic activity
of the macrolide
Theophylline
Increases serum
theophylline level
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Lincosamides
• Used for treating serious infections in which
penicillin or erythromycin is not effective
• Used for the more serious infections
• Used in conjunction with other antibiotics
• Actions: By inhibiting protein synthesis in
susceptible bacteria, causes cell death
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Examples of Lincosamides
• Cleocin / clindamycin
• Lincocin / lincomycin
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Lincosamides: Adverse Reactions
• Gastrointestinal/other body reactions
– Abdominal pain
– Nausea
– Vomiting
– Diarrhea
– Skin rash
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Lincosamides: Interactions
Interactant drug
Kaolin or
aluminum-based
antacids
Neuromuscular
blocking drugs
Effect of interaction
Decreases absorption of the
lincosamide
Increases action of
neuromuscular blocking
drug, possibly leading to
severe and profound
respiratory depression
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Nursing Process: Assessment
• Preadministration assessment
– Establish an accurate database before the
administration of any antibiotic
– Obtain general health history
– Record vital signs and obtain description
of signs and symptoms
– Note patient’s general appearance
– Obtain culture and sensitivity test results
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Nursing Process: Assessment (cont’d)
• Ongoing assessment
– Take vital signs every 4 hours or as
ordered
– Notify the primary health care provider if
there are changes in the vital signs or if
signs and symptoms worsen
– Compare current signs and symptoms of
infection and record any specific findings
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Nursing Process: Evaluation
• The therapeutic effect is achieved; infection
is controlled; normal vision unaffected; no
diarrhea
• Adverse reactions: Identified, reported, and
managed
• Patient and family demonstrate
understanding of drug regimen
• Patient verbalizes the importance of
complying with prescribed therapeutic
regimen
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End of Presentation
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