PHARM | Azithromycin

Everything Azithromycin.1️⃣ Azithromycin (Zithromax, Zmax)Class: Macrolide antibiotic (50S inhibitor). MOA: Inhibits bacterial protein synthesis → bacteriostatic/cidal by concentration. Use: Respiratory infections (strep pharyngitis, pneumonia), STIs (gonorrhea, chancroid), and MAC prophylaxis in advanced HIV. Contra: Hypersensitivity, prior cholestatic jaundice, QT prolongation, hypokalemia, or bradycardia → risk of Torsades de Pointes. Adverse / Interventions:QT Prolongation / Arrhythmia: Monitor cardiac status; avoid QT-prolonging drugs (quinidine, amiodarone).Hepatotoxicity / Cholestasis: Monitor LFTs (AST, ALT, LDH).SJS / TEN / Anaphylaxis: Stop immediately at first rash or swelling.C. Diff Diarrhea: Monitor stool frequency and hydration. Priority: Stop for severe skin reaction or anaphylaxis; watch for dysrhythmias.2️⃣ Aztreonam (Azactam, Cayston)Class: Monobactam β-lactam antibiotic. MOA: Bactericidal; binds cell-wall membrane → cell lysis. Use: Serious gram-negative infections (including Pseudomonas and multi-resistant strains). Contra: Hypersensitivity to aztreonam. Adverse / Interventions:Hypersensitivity / Anaphylaxis: Assess rash, wheezing, edema; notify HCP immediately.Superinfection (oral/vaginal candidiasis): Educate patient to report itching or discharge.Drowsiness/Dizziness: Caution with driving or machinery. Priority: Stop drug and treat if anaphylaxis occurs (fever, chills, dyspnea).3️⃣ AzathioprineClass: Immunosuppressant / DMARD. MOA: Antimetabolite that suppresses T-cell activity → ↓ immune response (prevents graft rejection). Use: Prevention of transplant rejection; treatment of rheumatoid arthritis. Contra: Severe infection or known hypersensitivity (others not specified). Adverse / Interventions:Bone Marrow Suppression: Monitor CBC and platelets; dose ↓ if < 3000 platelets.Hepatotoxicity: Monitor LFTs and bilirubin; report jaundice.GI Upset: Take with food to reduce nausea. Priority: Bone-marrow suppression = life-threatening → monitor labs and infection signs (fever, fatigue, bleeding, chills).🔥 Rapid Recall SummaryAzithromycin: Watch for QT prolongation & liver toxicity. Stop if rash or arrhythmia.Aztreonam: Kills Gram-negatives hard; monitor for anaphylaxis & superinfection.Azathioprine: Suppresses immune system; monitor CBC & LFTs—bone marrow and liver are targets.Mnemonic: 💊 Three A’s — Airway, Allergy, Anemia → Cardiac for Azithro, Anaphylaxis for Aztreo, Anemia for Azathioprine.