Spiramycin

Administration

  • Type: macrolide antibiotic
  • Dosage Forms:
  • Routes of Administration: PO, IV
  • Common Trade Names:

Adult Dosing

  • 1-2g PO BID OR 500-1000mg PO TID. May increase to 2-2.5g BID for severe infections
  • Toxoplasmosis in pregnant women:
    • 1st trimester: 3g PO daily in 3-4 divided doses
    • 2nd/3rd trimesters: 25-50mg pyrimethamine PO daily AND 2-3g sulfadiazine daily AND folinic acid 5mg daily for 3 weeks, alternating with 1g PO spiramycin TID for 3 weeks

Pediatric Dosing

  • >20kg: 25mg/kg PO BID or 16.7mg/kg PO TID
  • Subclinical congenital toxoplasmosis: 0.5-1mg/kg PO daily pyrimethamine AND 50-100mg/kg PO daily sulfadiazine x 4 weeks, alternating with 50-100mg/kg spiramycin x 6 weeks, alternating courses for 1 year
  • Overt congenital toxoplasmosis: 0.5mg/kg PO pyrimethamine daily AND 50-100mg/kg sulfadiazine PO daily AND 5mg folinic acid q3d for 6 months, alternating with 50-100mg/kg spiramycin AND pyrimethamine AND sulfadiazine for 4 weeks. Repeat dosing courses x 18mo

Special Populations

Pregnancy Rating

  • Category B, Safe in pregnancy[1]

Lactation risk

  • Distributed in breast milk

Renal Dosing

  • Adult:
  • Pediatric:

Hepatic Dosing

  • Caution in hepatic impairment

Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

  • Cardiac toxicity, specifically QT prolongation
  • Thrombocytopenia
  • Cholestatic hepatitis
  • GI toxicity, specifically acute colitis or other intestinal injury
  • Ulcerated esophagitis

Common

  • Injection site pain
  • Nausea/vomiting, diarrhea, abdominal pain

Pharmacology

  • Half-life: 4.5-13.5h
  • Metabolism: Hepatic
  • Excretion: Fecal

Mechanism of Action

  • Reversibly binds to the 50 S subunit of bacterial ribosomes, resulting in blockage of the transpeptidation or translocation reactions, inhibiting protein synthesis and subsequent cell growth

Comments

  • Not approved in US for standard use, though exceptions can be made to treat toxoplasmosis in pregnant women

See Also

References

  1. Stray-Pedersen B. Treatment of toxoplasmosis in the pregnant mother and newborn child. Scand J Infect Dis 1992; 84(suppl): 23-31

Authors:

Claire