zidovudine (Rx)

FDA-approved regimen

• 100 mg PO 5x/day until start of labor, in combination with other ART agents
• During labor and delivery: 2 mg/kg IV over 1 hr, THEN
• 1 mg/kg/hr IV continuous infusion until umbilical cord clamping 

NIH perinatal guidelines

• Indicated during labor and delivery for women who have received antepartum ART and their HIV RNA levels are >400 copies/mL, or in women who have not received antepartum ART
• 2 mg/kg IV loading dose infused over 1 hr, THEN 1 mg/kg/hr until umbilical cord clamping 
• Women who have received antepartum ART and their HIV RNA levels are <400 copies/mL do not require IV zidovudine
• IV would be preferred to oral administration in the United States; in situations where IV administration is not possible, oral administration can be considered

4 weeks to <18 years (manufacturer's prescribing information)

• 240 mg/m² PO q12hr or 160 mg/m² PO q8hr, OR use mg/kg dosing
• 4 to <9 kg: 12 mg/kg PO q12hr or 8 mg/kg PO TID
• ≥ 9 to <30 kg: 9 mg/kg PO q12hr or 6 mg/kg PO TID
• ≥30 kg: 300 mg PO q12hr or 200 mg PO TID
• IV intermittent infusion: 120 mg/m² IV q6h
• IV continuous infusion: 20 mg/m²/hr IV 

Neonates (NIH guidelines 2016)

• Dosage is determined by gestational age (GA in weeks) and birth age
• GA ≥35 weeks
  • Birth to 4 weeks: 4 mg/kg PO BID
  • >4 weeks: 12 mg/kg PO BID
• GA ≥30 to <35 weeks
  • Birth to 2 weeks: 2 mg/kg PO BID
  • 2 to 6-8 weeks: 3 mg/kg PO BID
  • >6-8 weeks: 12 mg/kg PO BID
• GA <30 weeks
  • Birth to 4 weeks: 2 mg/kg PO BID
  • 4 to 8-10 weeks: 3 mg/kg PO BID
  • >8-10 weeks: 12 mg/kg PO BID

Infants and children (NIH guidelines 2016)

• Aged ≥35 weeks postconception and at least 4 weeks postdelivery
• 4 to <9 kg: 12 mg/kg PO BID
• 9 to <30 kg: 9 mg/kg PO BID
• ≥30 kg: 300 mg PO BID
• BSA dosing: 180-240 mg/m² PO BID

Adolescents

• 300 mg PO BID

FDA approved regimen

• 2 mg/kg PO q6hr or 1.5 mg/kg IV q6hr 

NIH perinatal guidelines (July 2012)

• Dosage is determined by gestational age (GA in weeks) and birth age
• GA <30 weeks
  • Birth to 4 weeks: 2 mg/kg PO BID 
  • 4-6 weeks: 3 mg/kg PO BID
• GA ≥30 to <35 weeks
  • Birth to 2 weeks: 2 mg/kg PO BID 
  • 2 to 4-6 weeks: 3 mg/kg PO BID
• GA ≥35 weeks
  • Birth to 6 weeks: 4 mg/kg PO BID 

Administration, perinatal transmission prevention

• Initiate as soon after delivery as possible (preferably within 6-12 hr) and continue through age 4-6 weeks; (4 wk may be used when the mother has received standard ART during pregnancy with sustained viral suppression and there are no concerns related to maternal adherence)
• If IV administered, infuse over 30 minutes
• Additional antiretroviral prophylaxis needed (ie, nevirapine) for HIV-exposed infants of women who received no antepartum ART prophylaxis
• Also see Adult Dosing for maternal dosing guidelines