What Is The Reason For Thew Swelling In The Feet?

hallo my father is 83 year old hypertensive chronic heart patient got first triplebypass surgery done in in toronto canada got balloing done in 1993 in india again got unstable angania in 1999 balloing with stenting was done in india now got redocabg on 12 jan 2011 in medanta india after 6 weeks got swellings in feet & had left plural effusion persisted for 4 months first got tapping done but all the repots show normal results lately on 3 rd june they put a chest tube & drained fluid about 1.8litre and than put tetracycline ,after this procedure and a period of 6weeks he started getting swellings again than dr.advised and put him on these medicene showing good results weight has come back to nomal in 4 days only can u advise me that he is on right medication with no major side effects his latest blood reports for lft ,renal and other blood counts are nomal ,urine reports are nomal ultra sound & x ray chest is also back to normal showing no plural effusions he takes metolar 2.5mg at 9.30 am since last 5 days showing results with this,he takes lasix 40mg at 10 am &4pm nebistar 5 at 10am & 10pm telma 80 mg at 10 pm & ecosprin av 75+10 at 10 pm now he is stable with very less swelling in the feet and very less breathelessness can u guide that can i continue with same medication thanks bimal arora amritsar india mob 0000