In this task, you will be given sentences in which your task is to recognize the name of the drug or medicine. Drugs are substances that change a person's mental or physical state. They can affect how your brain works, how you feel and behave, your understanding, and your senses. Although there might be several correct answers, you need to write one of them.

Let me give you an example: Acute pain was observed after taking MTX
The answer to this example can be: MTX
Here is why: MTX is a medicine which has been mentioned here, and hence the name should be tagged.

OK. solve this:
In a single practice during the 21 years 1971-1991, the incidence of gestational diabetes in pregnancies in which norethisterone was prescribed was 32.4% (22 of 69) in comparison with 7.1% in pregnancies in which the women did not take norethisterone (137 of 1,684) (p < 0.001).
Answer:
norethisterone