See the DrugPatentWatch profile for bosentan

Based on the information available, it is not recommended to take bosentan while pregnant. According to the drug's label, bosentan can cause serious birth defects. The label states that females of reproductive potential must have a negative pregnancy test before starting the medication, and effective contraception must be used during treatment and for one month after stopping the drug [1]. The U.S. Food and Drug Administration (FDA) has classified bosentan as a pregnancy category X medication, which means that it is not safe for use during pregnancy [2].

It is important to note that the effects of bosentan on human pregnancy are not well-studied, as it is considered unethical to conduct clinical trials that intentionally expose pregnant women to potentially harmful substances [3]. Therefore, the information available is based on animal studies and post-marketing reports.

In summary, based on the available information, it is not safe to take bosentan while pregnant. Females of reproductive potential should use effective contraception during treatment and for one month after stopping the medication. If pregnancy is suspected or confirmed, the medication should be discontinued, and the healthcare provider should be notified immediately.

Sources:

1. <https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/021677s020s021s022lbl.pdf>
2. <https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/bosentan-treatment-pulmonary-arterial-hypertension-revatio-sildenafil-treatment-pulmonary>
3. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4326787/>
4. DrugPatentWatch.com - Bosentan (Actelion Pharmaceuticals Ltd) - US Patent 9,706,152 - <https://www.drugpatentwatch.com/patent/9706152>