Angiotensin receptor blockers

They block the AT1 receptor, so angiotensin II can no longer narrow arterioles or drive aldosterone release: vessels relax, the kidneys keep less sodium, and potassium can rise. They act at the receptor rather than on ACE, so bradykinin does not build up and cough is far rarer than with ACE inhibitors, though angioedema can still occur.

• LosartanPartly a prodrug: its active carboxylic acid metabolite does most of the receptor blocking.
• ValsartanThe ARB partnered with sacubitril in sacubitril/valsartan for heart failure.
• CandesartanThe NHS notes that doctors sometimes use it, outside its licence, to prevent migraine.
• TelmisartanCleared almost entirely through the bile rather than the kidneys, with the long half-life of about 24 hours.

• High blood pressure, as a first-line drug
• Heart failure
• Diabetic kidney disease with protein in the urine
• Weak left ventricle after a heart attack

• High potassium (hyperkalemia)Known forSerious
• Harm to the unborn baby (fetal toxicity)Known forSerious
• Low blood pressure on starting, if salt or water depleted
• Worsening kidney functionSerious
• Angioedema (rare)Serious
• Dizziness
• Headache
• Back pain
• Liver injury, including hepatitis (rare)Serious
• Muscle breakdown (rhabdomyolysis), rareSerious

What the class has in common. Each drug's card has its own, and Known for marks what an exam expects you to know.

• Pregnancy: stop as soon as it is detected, as they can injure or kill the developing baby.
• Do not combine with an ACE inhibitor, or with aliskiren in diabetes: more hyperkalemia, low blood pressure and kidney injury.
• Check potassium and kidney function, especially with potassium supplements, potassium-sparing diuretics, NSAIDs or kidney disease.
• They raise lithium levels and can cause lithium toxicity.

Written for biofideX in plain words, after checking these references:

• Angiotensin II Receptor Antagonist (NCI Thesaurus)
• Losartan potassium tablets: label (DailyMed)
• Valsartan tablets: label (DailyMed)
• Candesartan cilexetil tablets: label (DailyMed)
• Guideline for the pharmacological treatment of hypertension in adults (WHO)
• Losartan (NHS)

For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.