What are the criteria for holding metoprolol (Lopressor) HCTZ (hydrochlorothiazide) and lisinopril in patients with hypotension or impaired renal function?

Holding Criteria for Metoprolol, HCTZ, and Lisinopril

Beta-blockers (metoprolol), ACE inhibitors (lisinopril), and thiazide diuretics (HCTZ) should be held when systolic blood pressure is below 90 mmHg or if there is significant worsening of renal function. 1

Blood Pressure Criteria for Holding Medications

Metoprolol

• Hold if systolic BP <90 mmHg 1
• Hold if signs of cardiogenic shock or risk factors present:
  • Age >70 years
  • Systolic BP <120 mmHg
  • Heart rate >110 bpm or <60 bpm
  • Signs of heart failure or low output state 1

Lisinopril

• Hold if systolic BP <90 mmHg 1
• Hold if systolic BP has decreased by >30 mmHg from baseline 1
• If prolonged hypotension occurs (systolic BP <90 mmHg for more than 1 hour), lisinopril should be withdrawn completely 2

Hydrochlorothiazide (HCTZ)

• Hold if systolic BP <90 mmHg 1
• Hold if signs of hypovolemia are present 1
• Consider reducing dose if patient has symptomatic hypotension causing dizziness/light-headedness 1

Renal Function Criteria

Metoprolol

• No specific renal function cutoff for holding, but use with caution in severe renal dysfunction 1

Lisinopril

• Reduce dose by 50% if creatinine clearance ≤30 mL/min 2
• Consider holding if acute worsening of renal function occurs 2
• Hold if serum creatinine >2.5 mg/dL in men or >2.0 mg/dL in women 1

Hydrochlorothiazide (HCTZ)

• Consider switching to loop diuretic if creatinine >2.5 mg/dL or eGFR <30 mL/min/1.73m² 1
• Hold if significant worsening of renal function occurs with therapy 1

Electrolyte Abnormalities

Lisinopril

• Hold if serum potassium ≥5.0 mEq/L 1

Hydrochlorothiazide (HCTZ)

• Hold if significant hypokalemia (K+ ≤3.5 mmol/L) 1
• Hold if significant hyponatremia develops 1

Special Considerations

Heart Failure Patients

• In heart failure patients, beta-blockers may be poorly tolerated even at low doses 1
• For patients with heart failure, if hypotension occurs with ACE inhibitors, the diuretic dose may need to be adjusted to minimize hypovolemia 2
• In acute decompensated heart failure, temporary holding of beta-blockers may be necessary 1

Combination Therapy Considerations

• When using all three medications together (metoprolol, lisinopril, and HCTZ), monitor closely for additive hypotensive effects 1
• The combination of ACE inhibitors and diuretics increases the risk of renal dysfunction 1

Resuming Medications

• Once blood pressure has stabilized above 90 mmHg, medications can be restarted, often at lower doses
• For lisinopril, consider restarting at half the previous dose if it was held for hypotension 2
• For metoprolol, restart at a lower dose and titrate slowly if it was held for bradycardia or hypotension 1
• Patients with initial contraindications to beta-blockers should be reevaluated to determine subsequent eligibility 1

Common Pitfalls to Avoid

1. Failing to monitor blood pressure and renal function regularly in patients on these medications
2. Abruptly discontinuing beta-blockers, which can lead to rebound hypertension or tachycardia
3. Not adjusting diuretic doses when initiating or uptitrating ACE inhibitors
4. Overlooking the need for more frequent monitoring in elderly patients or those with baseline renal impairment
5. Not recognizing that hypotension may be more pronounced in volume-depleted patients

Remember that these medications affect each other - diuretics can potentiate the hypotensive effects of ACE inhibitors and beta-blockers, so a holistic approach to holding criteria is essential.