Is intravenous (IV) clarithromycin safe to administer?

Safety of Intravenous Clarithromycin Administration

Intravenous clarithromycin is safe to administer when appropriate precautions are taken regarding dosing, drug interactions, and patient-specific factors. 1

Administration and Dosing

Intravenous clarithromycin is administered as follows:

• Standard adult dose: 500 mg twice daily given through a large proximal vein 1
• Pediatric dose:
  • Children 1 month-11 years: 7.5 mg/kg (max 500 mg) twice daily
  • Children 12-18 years: 500 mg twice daily 1
• Duration: Typically 7 days for most infections, may be longer for specific conditions

Safety Considerations

Contraindications

• History of hypersensitivity to any macrolide agent 1
• Concomitant administration with:
  • Astemizole
  • Cisapride
  • Pimozide
  • Terfenadine 1, 2
• Not recommended for infants aged <1 month due to potential association with infantile hypertrophic pyloric stenosis (IHPS) 1

Drug Interactions

Clarithromycin is a potent inhibitor of the CYP3A enzyme system, requiring caution with:

• QT-prolonging medications: Monitor ECG for QTc prolongation 2
• Ergotamine/dihydroergotamine: Contraindicated due to risk of acute ergot toxicity 2
• Benzodiazepines: May increase levels of triazolam, alprazolam, midazolam 2
• HMG-CoA reductase inhibitors: Risk of rhabdomyolysis 2
• Other medications: Cyclosporine, carbamazepine, tacrolimus, alfentanil, disopyramide, rifabutin, quinidine, methylprednisolone, cilostazol, bromocriptine, sildenafil 1, 2

Dosage Adjustments

• Hepatic impairment: No dosage adjustment needed with normal renal function 1
• Renal impairment: Dosage adjustment required; interval between doses should be reassessed 1
• Elderly patients: Consider dosage adjustment with severe renal impairment 2

Adverse Effects

Common Adverse Effects

• Gastrointestinal: Abdominal pain (2%), diarrhea (3-6%), nausea (3%), vomiting (6%), taste perversion (3-19%) 1
• Neurological: Headache (2%) 1

Serious Adverse Effects

• Cardiovascular: QTc prolongation (rare) 1
• Dermatological: Anaphylaxis, leucocytoclastic vasculitis, toxic epidermal necrolysis, Stevens-Johnson syndrome (rare) 1
• Hepatic: Hepatomegaly, hepatic dysfunction, hepatic failure (rare) 1
• Ototoxicity: Hearing loss and tinnitus with long-term use 1
• Clostridium difficile-associated diarrhea and colitis 1

Monitoring Recommendations

• ECG: Baseline, 2 weeks after initiation, and after adding any QT-prolonging medication 1
• Audiometry: Baseline and if symptoms develop 1
• Laboratory tests: Periodic monitoring of complete blood count, renal and liver function 1

Special Populations

Pregnancy

• Pregnancy Category C 1
• Animal studies have shown adverse effects on the fetus 1
• Use only if potential benefit justifies potential risk to the fetus 2

Nursing Mothers

• Exercise caution as clarithromycin is excreted in the milk of lactating animals 2
• Other drugs of this class are excreted in human milk 2

Pediatric Use

• Safety not established in children under 6 months 2
• Not recommended for infants <1 month due to potential IHPS risk 1

Clinical Pearls

• IV clarithromycin should be infused through a large proximal vein to minimize vein irritation 1
• When switching from IV to oral therapy, the same total daily dose can be used 1
• For patients already receiving antibiotics that are also used for prophylaxis, select an antibiotic from a different class rather than increasing the dose of the current antibiotic 1
• Clarithromycin achieves high concentrations in respiratory tissues, making it particularly effective for respiratory infections 3, 4

By following these guidelines and considering patient-specific factors, IV clarithromycin can be administered safely and effectively for appropriate indications.