Recurrence of symptomatic patent ductus arteriosus in extremely premature infants, treated with indomethacin.

The administration of a single intravenous injection of indomethacin was followed by a major constrictive effect on the ductus in 36 of 42 very-low-birth-weight (less than or equal to 1000 gm) infants with symptomatic patent ductus arteriosus (PDA). In 26 of the 36 responders, the effect was sustained; symptomatic PDA recurred in the remaining 10. Infants who experienced a recurrence of symptomatic PDA had lower birth weights and had received indomethacin at an earlier postnatal age than did infants with a sustained effect. These results may be explained by differences in the production and clearance of prostaglandins or in the sensitivity of the ductus to prostaglandin effects between infants with a recurrence and infants with sustained constriction of PDA.