All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
By its very nature, a pig is filthy and so is its flesh, bone and skin; therefore, everything extracted from it is filthy as well. In this regard, Allah, the most Exalted, says (What means): " Forbidden to you (for food) are: dead meat, blood, the flesh of swine, and that on which hath been invoked the name of other than Allah." [Al-Maidah/3].
Therefore, substances and medical preparations in which any amount of pork is used to manufacture are prohibited to use unless for a necessity or in case no alternative is available.
If the medicine extracted from cows is as effective as the one extracted from pork; then using the latter is prohibited.
In conclusion, trustworthy medical specialists are the only authority entitled to decide which medicine is more effective, achieves the desired results and reduces mortality. And Allah the Almighty knows best.