Classifications: macrolide antibiotic; Therapeutic: antibiotic
Pregnancy Category: C
250 mg enteric tablets
Dirithromycin is an analog of erythromycin. It binds reversibly to the 50-S ribosomal subunit of the bacteria, thus inhibiting
RNA-dependent protein synthesis in bacterial cells. It has no apparent effect on the cytochrome P-450 hepatic enzyme system
as erythromycin does.
It is more active against gram-positive organisms than gram-negative organisms.
Acute bacterial exacerbations of chronic bronchitis, community-acquired pneumonia, pharyngitis/tonsillitis, uncomplicated
skin/skin structure infections due to susceptible bacteria.
Known hypersensitivity to dirithromycin, erythromycin, or any other macrolide antibiotic; known or suspected bacteremias;
viral infections; pregnancy (category C).
Severe hepatic impairment, GI disease; lactation. Safety and effectiveness in children <12 y are not established.
Route & Dosage
Adult/Child: PO 500 mg once/d
- Give with food or within 1 h of eating.
- Do not cut, crush, or chew tablets.
- Store at 15°30° C (59°86° F).
Adverse Effects (≥1%)CNS:
Headache, dizziness, asthenia. CV:
Chest pain. GI: Abdominal pain, nausea, diarrhea, vomiting, dyspepsia, flatulence;
elevated liver function tests (ALT, AST, GGT). Skin:
Rash, urticaria. Respiratory:
Dyspnea, asthma-like symptoms, rhinitis, pharyngitis, increased coughing.
May increase theophylline
Readily absorbed from GI tract; 6090% hydrolyzed to active metabolite, erythromycylamine, within 35 min. Peak:
1.5 h. Distribution:
High tissue concentrations of active metabolite; slowly released back into the circulation. Metabolism:
Rapidly converted to active metabolite, erythromycylamine, in absorption and distribution phases. Elimination:
8197% in bile and feces. Half-Life:
Assessment & Drug Effects
- Take history of previous hypersensitivity to other macrolides (e.g., erythromycin) prior to initiation of therapy.
- Withhold drug and notify physician if signs and symptoms of hypersensitivity occur (see Appendix F).
- Monitor liver and renal function in patients with mild liver or renal impairment.
- Monitor for S&S of superinfection (see Appendix F).
- Monitor theophylline levels if given concurrently with dirithromycin.
- Note: Dirithromycin may increase the blood level of theophylline, necessitating theophylline dosage adjustment.
Patient & Family Education
- Take tablets whole and within 1 h of meals.
- Monitor for and report S&S of superinfection or pseudomembranous enterocolitis (see Appendix F).
- Report any worsening of signs and symptoms of infection.