Allergic Bronchopulmonary Aspergillosis ||Voriconazole || Side Effects

My father is diagnosed with the following medical conditions , Docs told he has only 20% of lungs left, he will be on 24*7 o2 support (4lpm) and suggested for a possible lung transplant but due to my father weakness (age 63) and other conditions we are thinking not to opt for lung transplant and go with medical management only . So docs are giving (Voriconazole (VORITEK 200MG ) , Tobramycin 300 MG , Nebsmart g,Levolin 0.63,Mucinac 600,Mucinac 600,Dytor 5MG ,DILZEM 30 MG,CLOPILET A 75M,Urimax D ) for his medical conditoins .. But after he started using this medication he become more weaken , and got more new problems like more dizziness , unable to talk properly , full water in legs , abdomen tightness and other problems he is facing ..but after using vori his serum ige levels are declining, so doc is pushing this only but i am seeing all the side effects of the drug in him, what should i do? Is there anyone who is in this situation ? who used voriconazole and cured? we are loosing hope dad by dad seeing him. So looking for some positive stories to hear.
Diagnosis. :
Allergic Bronchopulmonary Aspergillosis
Post Tubercular Sequelae
Known Case of Obstructive Airway Disease
Type I Respiratory Failure on LTOT
Cor Pulmonale
Severe Pulmonary Arterial Hypertension (RVSP - 85 mmHg)
Grade III/IV Progressive Dyspnoea, Cough with Purulent Expectoration
Cholelithiasis (Hyperechoic Calculi of 6 mm)