angiotensin II receptor blockers (ARBs)

Introduction

ARBs were developed to address the issue that some patients taking ACE inhibitors developed bradykinin-mediated angioedema or cough
ACE inhibitors act by blocking the formation of angiotensin II whereas ARBs act by blocking the actions of angiotensin II
as with ACE inhibitors, they are primarily used for:
- hypertension
- congestive cardiac failure
- preventing renal disease in diabetics
they may also reduce risk of stroke in those with cardiomegaly, and may reduce risk of recurrence of atrial fibrillation

low BP, postural dizziness and postural hypotension
hyperkalaemia risk
sinusitis, URTIs, viral illness susceptibility may be an issue
- ARBs increase ACE2 receptor numbers by 3-5x and some viruses (eg. COVID-19 coronavirus (2019-nCoV / SARS-CoV-2)) use these receptors to gain access to cells
most tolerate these meds well otherwise, however some develop metallic taste, indigestion, headache, fatigue, drowsiness, sexual dysfunction or diarrhoea
serious but rare adverse effects:
- acute renal failure (ARF) - especially if concurrent use of non-steroidal anti-inflammatory drugs (NSAIDs) whilst dehydrated as renal blood flow is impaired or in those with renal artery stenosis
- hepatitis
- HS reactions
- neutropenia
- thrombocytopenia
- rhabdomyolysis