Antibiotics - Macrolides: Nursing pharmacology

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ANTIBIOTICS: MACROLIDES
DRUG NAME
erythromycin (Ery-tab, Erythrocin)
azithromycin (Zithromax)
clarithromycin
CLASS
Macrolides
MECHANISM OF ACTION
Bind to bacterial 50S ribosomal subunit → suppress protein synthesis and bacterial growth
INDICATIONS
Mild to moderate respiratory tract, skin, soft-tissue infections
Mild to moderate respiratory tract, skin, soft-tissue infections
  • Disseminated MAC infections
  • Chlamydia, chancroid, syphilis, gonorrhea
  • Traveler’s diarrhea
  • Bacterial conjunctivitis
Mild to moderate respiratory tract, skin, soft-tissue infections
  • Acute exacerbation of chronic bronchitis
  • Endocarditis prophylaxis
  • MAC prophylaxis / treatment
  • H. pylori infection
ROUTE(S) OF ADMINISTRATION
  • PO
  • IV infusion
  • PO
  • Ophthalmic
  • PO
SIDE EFFECTS
  • CNS: headache, seizures
  • CV: QT prolongation, torsades de pointes (rare)
  • EENT: ototoxicity
  • GI: nausea, vomiting, diarrhea, abdominal pain, Clostridioides difficile infection (CDI), hepatotoxicity
  • GU: vaginitis, candidiasis
  • INTEG: skin rash
  • SYST: angioedema, Stevens-Johnson syndrome, toxic epidermal necrolysis
  • Erythromycin: esophagitis
  • Azithromycin: thrombocytopenia (rare)
  • Clarithromycin: abnormal taste, pancreatitis
CONTRAINDICATIONS AND CAUTIONS
  • Hepatic disease
  • Cardiovascular disease
  • Pregnancy, breastfeeding
  • Elderly clients
  • Drug interactions: quinidines, amiodarone, pimozide, ergots, statins
NURSING CONSIDERATIONS
Assessment and monitoring: azithromycin
Assessment
  • Signs / symptoms of infection
  • Laboratory test results
  • Presence of cardiac arrhythmia
  • Current medications that are CYP34A inhibitors

Monitoring
  • Side effects
  • Infection resolution
  • Absence of symptoms

Client education
  • Purpose of medication: treat infection
  • Dose: one tablet taken with or without food
  • Abstain from sexual activity for seven days, starting after the completion of therapy
  • Side effects to report
    • CDI
    • Hepatotoxicity
    • Ototoxicity
    • QT prolongation

Memory Anchors and Partner Content

Transcript

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Macrolides are a class of antibiotics used to treat a wide range of infections caused by gram-positive and gram-negative bacteria. These medications include erythromycin, azithromycin, and clarithromycin.

All can be administered orally to treat mild to moderate bacterial infections of the respiratory, gastrointestinal, and genitourinary tracts; erythromycin can also be given intravenously, and azithromycin has an ophthalmic formulation to treat bacterial conjunctivitis.

Now, once administered, macrolides target the bacterial 50S ribosomal subunit in order to inhibit protein synthesis. As a result, these medications have a bacteriostatic effect, meaning they stop bacterial growth.

They’re also considered broad spectrum antibiotics, as they’re active against most gram-positive bacteria and moderately active against some gram-negative bacteria.

Typically, macrolides are well tolerated, and rarely cause side effects. The most common ones can include headaches, a skin rash, and gastrointestinal disturbances like diarrhea, abdominal pain, nausea, and vomiting.

In addition, macrolides may disrupt the normal intestinal flora, which can allow certain bacteria like Clostridioides difficile to survive and overgrow within the gastrointestinal tract, rarely but potentially leading to Clostridioides difficile infection or CDI for short.

Some clients on macrolides may also develop vaginitis and candidiasis, and if they’re used for a prolonged time, they can also lead to ototoxicity and hearing loss.

Now, more serious side effects include a prolonged QT interval, ventricular arrhythmias like torsade de pointes, and hepatotoxicity, potentially leading to hepatitis.

They can also cause seizures, and rare but serious hypersensitivity reactions like angioedema, Stevens-Johnson syndrome, and toxic epidermal necrolysis.