Macrolides

Macrolides

Drug monograph · NCLEX study reference
Therapeutic class	Antibacterial
Pharmacologic class	Macrolide
Onset / peak / duration	Azithromycin has a long tissue half-life (short courses, once daily).
Half-life / level	Azithromycin about 68 hours; no routine level.
Routes	PO (oral), IV
High-alert (ISMP)	No
Black box warning	None
Antidote / reversal	Supportive care.
Pregnancy / lactation	Azithromycin commonly used when needed.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Macrolides — Antibacterial; Macrolide.

Identification

• Therapeutic class: Antibacterial.
• Pharmacologic class: Macrolide.

Pharmacology

• Mechanism of action: Bind the 50S ribosomal subunit to inhibit protein synthesis (bacteriostatic).
• Onset / peak / duration: Azithromycin has a long tissue half-life (short courses, once daily).
• Half-life / therapeutic level: Azithromycin about 68 hours; no routine level.

Clinical use

• Indications: Respiratory infections, atypical pneumonia, pertussis, sexually transmitted infections, H. pylori (clarithromycin).
• Usual dose, route, frequency: Azithromycin PO once daily (often a 5-day pack) or IV; erythromycin several times daily.
• Maximum dose / adjustments: Caution in hepatic impairment and with QT risk.

Safety

• Contraindications: Hypersensitivity, history of cholestatic jaundice with macrolides, certain QT-prolonging drug combinations.
• Black box warning: None.
• Interactions: QT-prolonging drugs, warfarin, statins (clarithromycin and erythromycin via CYP3A4, myopathy), digoxin; food affects some.
• Pregnancy / lactation: Azithromycin commonly used when needed.
• High-alert: No.

Adverse effects

• Common side effects: GI upset, diarrhea, abdominal cramping (erythromycin notably), taste changes.
• Serious effects to report: QT prolongation and arrhythmia, hepatotoxicity, C. difficile colitis.
• Antidote / reversal: Supportive care.

Nursing process

• Assessment before administration: Allergy, cardiac and QT history, interacting drugs, hepatic function.
• Interventions during therapy: Review QT-prolonging and CYP3A4 drugs.
• Monitor: Cardiac status if at risk, LFTs, infection resolution.
• Evaluation / expected outcome: Resolution of infection.

Patient teaching

• Patient teaching: Finish the course; report palpitations; take erythromycin with food for GI upset.
• Notify provider if: Palpitations, fainting, yellowing of skin, severe diarrhea.
• Administration tips: Azithromycin with or without food; separate from aluminum and magnesium antacids.