In an 86‑year‑old man two days post‑hip surgery with hypotension (blood pressure 100/60 mmHg), tachycardia (heart rate 100 bpm) and chronic low‑back pain, which of the following medications—Entresto (sacubitril/valsartan), Cardura (doxazosin), Proscar (finasteride), melatonin, Remeron (mirtazapine), or trazodone—should be given at 8 pm?

Medication Administration Decision in Post-Operative Hypotensive Patient

Immediate Recommendation

In this 86-year-old man two days post-hip surgery presenting with hypotension (BP 100/60 mmHg) and tachycardia (HR 100 bpm), only melatonin and Proscar (finasteride) should be administered at 8 pm; all other medications—Entresto, Cardura, Remeron, and trazodone—must be withheld until hemodynamic stability is achieved.

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Rationale for Withholding Specific Medications

Entresto (Sacubitril/Valsartan) – HOLD

• Entresto causes symptomatic hypotension significantly more frequently than standard ACE inhibitors and is associated with serious cardiovascular complications when administered during hypotensive states 1, 2.
• A case report documented recurrent hypotension and tachyarrhythmia in a patient unable to tolerate even small doses of sacubitril/valsartan, requiring discontinuation 2.
• ACE inhibitors and ARBs should be withheld in patients with persistent postoperative hypotension and resumed only after hemodynamic stability is established, typically within 48 hours post-surgery 3.
• The current blood pressure of 100/60 mmHg with tachycardia represents persistent hypotension requiring preload assessment and potential vasopressor support rather than afterload reduction 3.

Cardura (Doxazosin) – HOLD

• Alpha-1 blockers such as doxazosin cause vasodilation and orthostatic hypotension, which would exacerbate the patient's existing hypotension and increase fall risk in the immediate post-operative period 3.
• Perioperative guidelines emphasize that all antihypertensive medications should be omitted if a patient is hypotensive 3.
• Alpha-agonists (the therapeutic class to which doxazosin belongs as an antagonist) should be resumed only after beta-blockers and ACE inhibitors/ARBs are restarted and the patient is normotensive 3.

Remeron (Mirtazapine) – HOLD

• Mirtazapine causes significant sedation (19% vs 5% placebo) and drowsiness (23% vs 14% placebo), which would impair the patient's ability to report symptoms of end-organ hypoperfusion and increase delirium risk 4.
• The drug's alpha-2 adrenergic antagonist properties can cause orthostatic hypotension, particularly dangerous in elderly post-surgical patients with baseline hypotension 4.
• Sedating medications must be used cautiously in the very elderly and should be avoided during periods of hemodynamic instability when continuous neurological assessment is required 3, 5.

Trazodone – HOLD

• Trazodone has not been shown effective for chronic low back pain and carries significant sedation risk that would mask symptoms of hemodynamic deterioration 3.
• The combination of sedation and alpha-1 adrenergic blockade (causing vasodilation) makes trazodone particularly hazardous in hypotensive patients 3.
• Drugs that lower blood pressure indirectly through anxiolysis and sedation must be used with extreme caution in patients prone to rapid desaturation and those with compromised hemodynamics 3.

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Medications Safe to Administer

Melatonin – GIVE

• Melatonin has no significant cardiovascular effects and does not cause hypotension or interact with hemodynamic management 5.
• It may improve sleep quality without the delirium risk associated with benzodiazepines or sedating antidepressants 5.

Proscar (Finasteride) – GIVE

• Finasteride is used for benign prostatic hyperplasia and has no acute cardiovascular effects or interactions with blood pressure 3.
• Missing a single dose poses no immediate clinical risk, but continuation maintains therapeutic benefit without hemodynamic consequences.

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Critical Management Priorities Before Medication Resumption

Immediate Hemodynamic Assessment

• Perform a passive leg raise (PLR) test to determine if hypotension is preload-responsive; if PLR increases blood pressure, administer intravenous fluid; if not, vasopressor or inotropic support is indicated 3.
• Maintain mean arterial pressure >65 mmHg, as hypotension below this threshold for approximately 15 minutes is associated with postoperative myocardial injury, acute kidney injury, and mortality 3, 5.
• Have phenylephrine (100-200 mcg bolus) or metaraminol immediately available and administer vasopressors before additional IV fluids to prevent volume overload 3, 5, 6.

Rule Out Reversible Causes

• Assess for pain (currently 5/10), anxiety, hypothermia, hypoxemia, urinary retention, and occult bleeding as treatable causes of tachycardia and hypotension before attributing symptoms to medication withdrawal 3.
• The heart rate of 100 bpm may represent compensatory tachycardia for hypovolemia, pain response, or early sepsis rather than a primary cardiac issue 3.

Pain Management Without Hemodynamic Compromise

• Administer scheduled acetaminophen 1000 mg IV or PO every 6 hours (maximum 4 g/24 hours) as first-line analgesia for the patient's 5/10 chronic lower back pain 7, 5.
• Consider topical analgesics for localized pain components to avoid systemic drug interactions 7.
• NSAIDs should be avoided due to heightened risk of renal impairment, cardiovascular events, and gastrointestinal bleeding in this 86-year-old post-surgical patient 7.
• If opioids are required for breakthrough pain, reduce the dose by 20-25% per decade after age 55 to account for altered drug metabolism 5, 7.

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Timeline for Medication Resumption

Entresto and Cardura

• Resume Entresto only after systolic blood pressure is consistently >100 mmHg without vasopressor support and heart rate is <90 bpm for at least 12-24 hours 3, 2.
• Restart Cardura only after Entresto has been successfully resumed and the patient demonstrates stable blood pressure in the normotensive range 3.
• Monitor blood pressure closely for the first 48-72 hours after restarting either medication, as delayed resumption of ACE inhibitors/ARBs beyond 48 hours post-surgery is associated with increased 30-day mortality risk 3.

Remeron and Trazodone

• Restart sedating medications only after hemodynamic stability is confirmed and the patient is ambulatory without orthostatic symptoms 3, 5.
• Avoid long-acting benzodiazepines entirely, as they are strongly associated with postoperative delirium in patients over 60 years 5, 6.

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Common Pitfalls to Avoid

• Never administer all missed morning medications simultaneously at 8 pm without reassessing hemodynamic status; this "catch-up" approach can precipitate severe hypotension, bradycardia, and cardiovascular collapse 3.
• Do not attribute tachycardia solely to medication withdrawal; search for alternative causes such as sepsis, hypovolemia, pulmonary embolism, and anemia that would warrant short-term discontinuation of beta-blocker therapy 3.
• Avoid excessive IV fluid administration for spinal-induced or medication-related hypotension; use vasopressors first, as only 54% of hypotensive patients respond to fluid boluses 3.
• Clinically significant hypotension is associated with an adjusted odds ratio of death and stroke of 4.97 (95% CI 3.62-6.81), and clinically significant bradycardia with an adjusted odds ratio of 2.13 (95% CI 1.37-3.12) 3.