Why would a doctor hold losartan (angiotensin II receptor antagonist) in a patient in the psychiatry ward?

Why Losartan Would Be Held in a Psychiatry Ward Patient

Losartan should be held in psychiatry ward patients primarily due to hypotension risk, particularly in the context of orthostatic hypotension from psychotropic medications, volume depletion, or acute medical instability requiring hemodynamic monitoring.

Primary Clinical Scenarios for Holding Losartan

Hypotension and Orthostatic Changes

• Psychotropic medications commonly cause orthostatic hypotension, particularly selective serotonin reuptake inhibitors (SSRIs), antipsychotics, and alpha-1 blockers used in psychiatry 1
• Losartan combined with these agents increases the risk of symptomatic hypotension and falls, which are particularly dangerous in psychiatric patients who may have impaired judgment or coordination 1
• Calcium channel blockers and alpha-1 blockers should be used with care in patients with orthostatic hypotension, and the same caution applies to angiotensin receptor blockers like losartan 1

Volume Depletion States

• Psychiatric patients may present with volume depletion from poor oral intake, excessive sweating, or concurrent illness 2
• Losartan can exacerbate hypotension in hypovolemic states, making it necessary to hold the medication until volume status is optimized 2
• Pain, anxiety, inflammation, or urinary retention can contribute to hemodynamic instability in the postoperative or acute care setting 2

Drug Interactions and Safety Monitoring

• The risk of pharmacologic interactions, ECG abnormalities, and postural blood pressure changes must be considered when managing hypertension in psychiatric patients 1
• RAS inhibitors like losartan are preferred in psychiatric patients when blood pressure control is needed, but only after ensuring hemodynamic stability 1
• Beta-blockers (not metoprolol) may be needed for drug-induced tachycardia from antidepressants or antipsychotics, and adding losartan in this context requires careful blood pressure monitoring 1

Specific Situations Requiring Losartan Hold

Acute Medical Instability

• Losartan should be held during acute medical crises such as sepsis, acute kidney injury, or severe dehydration until the patient is stabilized 2
• Hyperkalemia (potassium ≥5.0 mEq/L) or significantly elevated creatinine (≥2.5 mg/dL in men, ≥2.0 mg/dL in women) are contraindications to continuing losartan 1
• Renal artery stenosis or worsening renal function with ARB exposure requires discontinuation 1

NPO Status or Inability to Take Oral Medications

• Patients who cannot take oral medications due to altered mental status, NPO orders, or gastrointestinal issues should have losartan held 2
• Alternative intravenous antihypertensive agents should be considered if blood pressure control is urgently needed 2

Severe Hypotension or Shock

• Systolic blood pressure <90 mmHg or signs of shock are absolute contraindications to continuing losartan 1
• Bilateral renal artery stenosis can precipitate acute renal failure with ARB use 1

When to Resume Losartan

Resumption Criteria

• Resume losartan as soon as the patient can take oral medications and is hemodynamically stable 2
• Delaying resumption of ARBs beyond necessary has been associated with increased 30-day mortality risk 2
• Monitor blood pressure regularly during the first 24-48 hours after resuming losartan 2

Monitoring Parameters

• Check serum potassium and creatinine before resuming and 1-2 weeks after restart 3
• Target blood pressure should generally maintain systolic <180 mmHg and diastolic <110 mmHg in the acute setting 2
• Avoid intensification of antihypertensive therapy at discharge, as this increases 30-day readmission risk and complications, particularly in older adults 2

Common Pitfalls to Avoid

• Do not abruptly withdraw losartan without cause, as this may lead to rebound hypertension 2
• Avoid combining losartan with ACE inhibitors, as this increases hyperkalemia and renal dysfunction risk without additional benefit 4
• Be cautious with volume status assessment—hypovolemia exacerbates hypotension when losartan is resumed 2
• Psychiatric patients on multiple medications require close monitoring for drug interactions and cumulative hypotensive effects 1