Can I give hydralazine (apresoline) to a patient with a blood pressure reading of 125/45 mmHg, indicating hypotension?

Do Not Administer Hydralazine with BP 125/45

With a blood pressure of 125/45 mmHg, you should withhold the scheduled hydralazine dose—the diastolic pressure of 45 mmHg indicates the patient is already significantly hypotensive and at high risk for symptomatic hypotension and end-organ hypoperfusion if blood pressure is further reduced. 1, 2

Why This Blood Pressure Contraindicates Hydralazine

The Diastolic Reading is Critically Low

• A diastolic blood pressure of 45 mmHg is significantly below the normal range and indicates the patient is already hypotensive 2
• Guidelines recommend withholding scheduled hydralazine when diastolic readings are below 60 mmHg 1, 2
• This low diastolic pressure creates substantial risk for symptomatic hypotension if any vasodilator is administered 1

Hydralazine's Pharmacologic Profile Creates Unacceptable Risk

• Hydralazine is a direct-acting vasodilator that begins lowering blood pressure within 10-30 minutes with effects lasting 2-4 hours 1, 3
• The drug has unpredictable response patterns and prolonged duration of action, making it unsuitable for use when blood pressure is already low 1
• In hospitalized patients, hydralazine causes highly variable blood pressure changes, with hypotension being the most common adverse event (occurring in 11 of 94 patients in one study) 4

Immediate Management Steps

Hold the Medication and Monitor

• Withhold the scheduled hydralazine dose immediately 1, 2
• Monitor blood pressure closely for trends rather than treating a single reading 1
• Evaluate for causes of the low diastolic pressure: volume depletion, medication effects, or cardiac issues 2

Assess for Symptoms of Hypoperfusion

• Check for dizziness, lightheadedness, or syncope 3
• Consider fluid resuscitation if the patient is symptomatic from hypotension 2

Contact the Prescribing Physician

• If the patient is on scheduled hydralazine for heart failure (particularly in combination with isosorbide dinitrate), consult with the prescribing physician about temporarily holding the dose 1, 2
• The European Society of Cardiology guidelines note that symptomatic hypotension from hydralazine-isosorbide dinitrate therapy should prompt dose reduction, and asymptomatic hypotension does not require intervention—but a diastolic of 45 mmHg warrants clinical concern regardless 5

When Hydralazine is Actually Indicated

Appropriate Clinical Scenarios

• Hypertensive emergencies when administered intravenously 1, 2
• Resistant hypertension as a step 5 agent (when blood pressure is actually elevated) 1, 2
• Heart failure with reduced ejection fraction in combination with isosorbide dinitrate, particularly in African American patients 5, 1, 2

None of These Apply to Your Patient

• The systolic pressure of 125 mmHg does not meet criteria for hypertension (threshold is 140 mmHg) 1
• There is no hypertensive emergency present 1
• Even if prescribed for heart failure, the current blood pressure contraindicates administration 1, 2

Common Pitfall to Avoid

Do not give scheduled antihypertensive medications based solely on the fact that they are "scheduled"—always verify that the current blood pressure supports safe administration. 1, 4 The most common error with hydralazine in hospitalized patients is inappropriate use in non-urgent situations, which leads to hypotension as the primary adverse event 4. In this case, with a diastolic already at 45 mmHg, administering hydralazine could precipitate symptomatic hypotension, falls, syncope, or end-organ hypoperfusion 1, 2, 4.