Drugs in Pregnancy and Lactation: Tenth Edition



PREGNANCY RECOMMENDATION: Compatible—Maternal Benefit >> Embryo–Fetal Risk



No reports describing the use of tenecteplase in human pregnancy have been located. The limited animal data do not suggest a direct risk. Moreover, fetal toxicity has not been observed with limited pregnancy exposure to another, similar glycoprotein enzyme, alteplase. Although maternal hemorrhage is a major risk, tenecteplase should not be withheld because of pregnancy if the maternal condition requires such therapy.


Tenecteplase is a modified form of human tissue plasminogen activator (tPA) that is produced by recombinant DNA technology using Chinese hamster ovary cells. It is a 527 amino acid glycoprotein that is indicated to reduce the mortality associated with acute myocardial infarction. Tenecteplase is cleared from the plasma with a half-life of 20–24 minutes, but the terminal phase half-life is 90–130 minutes (1).

In pregnant rabbits given multiple IV daily doses of 0.5, 1.5, and 5.0 mg/kg/day, vaginal hemorrhage resulted in maternal deaths. No fetal anomalies were observed. Single IV doses (the recommended human dose is a single bolus injection) in rabbits did not cause maternal or embryo toxicity. The no-observable-effect-level (NOEL) of a single IV dose was 5 mg/kg (about 8–10 times the human dose) (1).

It is not known if tenecteplase crosses the human placenta. Tenecteplase is a glycoprotein and, although some proteins do cross, the short plasma half-life will limit the exposure of the embryo–fetus to the enzyme.


No reports describing the use of tenecteplase during human lactation have been located. It is not known whether the glycoprotein is excreted into human milk. Because of the nature of the indication for this agent and its very short plasma and terminal half-life, the opportunities for its use during lactation or the possible exposure of a nursing infant are minimal.


1.Product information. TNKase. Genentech, 2004.