Understanding ACE Inhibitors and ARBs for High Blood Pressure

💊 Getting Started: What You Should Know

• Start Low, Go Slow
  When first starting an ACE-I or ARB, it’s common to begin with a low dose, especially in seniors. This reduces the risk of side effects like dizziness or low blood pressure.
  Pharmacist Tip: Monitor your blood pressure regularly at home — ideally at the same time each day — and report any large drops (e.g., systolic BP under 100 mmHg) to your provider.
• Watch for Side Effects
  1. Dry Cough – This is common with ACE inhibitors (like lisinopril) but not with ARBs.
  2. Dizziness or Lightheadedness – Especially during the first few weeks. Stand up slowly to avoid falls.
  3. Increased Potassium Levels – Both classes can raise potassium. You might not feel symptoms, so regular blood tests are important.
  4. Changes in Kidney Function – These drugs can slightly alter kidney labs, but this is usually manageable with monitoring.
     
     Pharmacist Tip: If you’re feeling faint, weak, or notice swelling, muscle cramps, or irregular heartbeat — contact your healthcare provider immediately.
• Don’t Use Salt Substitutes Without Checking
  Many salt substitutes contain potassium, which can interact with these drugs and raise potassium to dangerous levels.
• Hydration Matters
  Avoid dehydration, especially in hot weather or during illness (e.g., vomiting, diarrhea), as these medications can make kidney function worse when you’re volume depleted.
• Avoid NSAIDs
  Over-the-counter pain relievers like ibuprofen and naproxen can interfere with kidney function when taken with ACE-Is or ARBs. Always ask your pharmacist before using these meds.
• Pregnancy Warning
  These medications should not be used during pregnancy. Women of childbearing age should speak with their provider about safer alternatives or use effective contraception.

Tips for Switching from an ACE-I to an ARB

If you’ve been prescribed an ACE inhibitor but developed a persistent dry cough, your provider may switch you to an ARB, which has similar benefits but fewer respiratory side effects.

🔁 Tips During the Switch:

1. Ask if you need a washout period – most patients can switch directly, but your provider may recommend 1–2 days off depending on symptoms or blood pressure.
2. Monitor your BP daily during the first week on the new ARB — especially if your dose has changed.
3. Side effects may differ – although ARBs don’t usually cause a cough, dizziness or elevated potassium can still occur.
4. Notify your provider if you experience chest tightness, swelling, or sudden changes in urine output.

If you were on a combination pill (e.g., lisinopril-HCTZ), ask whether your new ARB will include the same diuretic.