Based on the information available, there is no straightforward answer to whether Bosentan can be taken with impaired liver function. Bosentan is a medication used to treat pulmonary arterial hypertension, and it is metabolized in the liver [1]. Therefore, liver function can affect how the body processes Bosentan.

The drug's prescribing information states that Bosentan should be used with caution in patients with mild or moderate liver impairment [2]. However, it is contraindicated in patients with severe liver impairment [2]. This means that the benefits of taking Bosentan may not outweigh the risks for patients with severe liver impairment.

It is important to note that the prescribing information also states that the dosage of Bosentan may need to be reduced in patients with liver impairment [2]. Therefore, patients with liver impairment who are taking Bosentan should be closely monitored by their healthcare provider.

In summary, while Bosentan can be taken with mild or moderate liver impairment, it should be used with caution. However, it is contraindicated in patients with severe liver impairment. Patients with liver impairment who are taking Bosentan should be closely monitored by their healthcare provider.

Sources:
[1] DrugPatentWatch.com. Bosentan. <https://www.drugpatentwatch.com/drugs/bosentan>.
[2] Tracleer (bosentan) tablets, for oral use. Full Prescribing Information. Actelion Pharmaceuticals US, Inc. <https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/021157s025s026s027lbl.pdf>.