Is Taking Mucinex Sinus-Max Normal, While On Losartan-HCTZ-100, Prednisone-10mg, Diltiazem-30mg And Furosemide-20mg?

HI, I have been sitting with an man that is 83 yrs old. he s on oxygen 24/7, and just got out of the hospital. the meds. he s on is : Losartan-hctz 100-12.5 once a day, prednisone 10 mg once a day, diltiazen 30 mg 1 every six hours, and furosemide 20 mg bid....his son went and bought him mucinex sinus-max...I was concerned about him taking this....I need to know if he should take this with the meds. he s already on.....he s also doing four hours a day the breathing treatment to help break up up the mucus....his BP is staying normal...what should I tell him about taking the mucinex...thanks...but I can t afford to pay for an answer...sorry to bother you...I for some reason thought this was free and I needed to know what to do for this very sick man......you have a bless day....again, thanks