Multiple drugs

Abstract

Various toxicities: case report A 62-year-old man developed hypotension while receiving diuretic therapy with azosemide, spironolactone and tolvaptan for congestive heart failure (CHF). Later, he developed tachycardia during treatment with amezinium-metilsulfate, and exhibited lack of efficacy during treatment with midodrine [not all routes and dosages stated]. The man had a history of CHF due to mitral regurgitation and complaints of dyspnoea on exertion. He underwent mitral annuloplasty. Thereafter, he was prescribed multiple medications for the management of CHF that included oral azosemide 60 mg/day, spironolactone 50 mg/day and tolvaptan 15 mg/day along with bisoprolol and enalapril. Subsequently, his systolic BP decreased to <90mm Hg and diastolic BP <60mm Hg, indicating hypotension, which was considered as related to the ongoing diuretics (azosemide, spironolactone and tolvaptan). With the use of diuretics, his systematic BP remained between 70–80 mmHg and he reported dizziness. However, it was not possible to reduce the dose or discontinue the use of diuretics due to the possible effects of oedema and weight gain. Hence, the man’s diuretics were continued. Subsequently, he had an exacerbation of heart failure, requiring hospital admission. At the time of admission, his HR was 88 beats/min, systolic BP was 83mm Hg and diastolic BP was 47mm Hg. On hospital day 3 (HD-3), oral midodrine 4 mg/day was started. Ejection fraction on HD-8 was noted as 53.4%, and he was categorised as heart failure with preserved ejection fraction (HFpEF). Also on HD-8, due to low urine volume, furosemide was added to the treatment regimen. The dose of midodrine was gradually increased to 8 mg/day in 9 days after initiation however, only a minor improvement was noted in his systolic BP. Oral amezinium-metilsulfate [amezinium] 20 mg/day was started on HD-25; however, it lead to the development of tachycardia. Hence, it was discontinued on HD-29. Due to ongoing HFrEF, enalapril was changed to losartan. On HD-35, despite ongoing midodrine therapy, his BP decreased further and his urine volume decreased significantly to <100 mL/day (indicating lack of efficacy). Losartan was stopped, dopamine was started. On HD 36, he underwent continuous haemodiafilteration (CHDF), and received IV norepinephrine [noradrenaline], atrial-natriuretic-peptide [human atrial natriuretic peptide]. Gradually, the BP increased, but it was noted that the increase in BP was not stable in the absence of norepinephrine. Eventually, on HD-47, based on previously published case reports, norepinephrine was changed to droxidopa. on HD-49, the dose of droxidopa was increased, and his systolic/diastolic BP increased to 100-120mm Hg and 60-80mm Hg, respectively. In the following eight days, no decrease was noted in his BP. Therefore, he was discharged on a combination of midodrine 8 mg/day and droxidopa with resolution of dizziness.