From the Guidelines
For a patient with severely elevated systolic blood pressure who has already received hydralazine, another antihypertensive agent should be added acutely to prevent end-organ damage. The most recent and highest quality study, the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1, recommends the use of intravenous antihypertensive drugs for the treatment of hypertensive emergencies.
Recommended Agents
- IV labetalol (initial 0.3–1.0-mg/kg dose, maximum 20 mg, slow IV injection every 10 min or 0.4–1.0-mg/kg/h IV infusion up to 3 mg/kg/h)
- IV nicardipine (initial 5 mg/h, increasing every 5 min by 2.5 mg/h to maximum 15 mg/h)
- Clevidipine (initial 1–2 mg/h, doubling every 90 s until BP approaches target, then increasing by less than double every 5–10 min; maximum dose 32 mg/h) are effective options for acute blood pressure management.
Key Considerations
- The goal is to reduce blood pressure by no more than 25% in the first hour, then to 160/100-110 mmHg within the next 2-6 hours, avoiding too rapid a decrease which could cause hypoperfusion.
- Monitor the patient closely with frequent blood pressure checks, continuous cardiac monitoring, and assessment for symptoms of end-organ damage.
- Hydralazine alone may be insufficient due to its variable response and potential for reflex tachycardia, as noted in the guideline 1.
From the FDA Drug Label
In a few resistant patients, up to 300 mg of hydrALAZINE hydrochloride tablets daily may be required for a significant antihypertensive effect. In such cases, a lower dosage of hydrALAZINE hydrochloride tablets combined with a thiazide and/or reserpine or a beta blocker may be considered However, when combining therapy, individual titration is essential to ensure the lowest possible therapeutic dose of each drug.
For a patient with severely elevated systolic blood pressure already given Hydralazine, another antihypertensive agent may be added acutely. The options to consider include:
- A thiazide
- Reserpine
- A beta blocker 2 Individual titration is essential to ensure the lowest possible therapeutic dose of each drug.
From the Research
Management of Severely Elevated Systolic Blood Pressure
In a patient already given Hydralazine (hydrochloride), the decision to add another antihypertensive agent acutely depends on the clinical presentation and the presence of end-organ damage.
- If the patient has a hypertensive emergency, characterized by acute end-organ damage, immediate reduction in blood pressure is required with a titratable, short-acting, intravenous antihypertensive agent 3.
- The use of Hydralazine is not recommended as a first-line therapy in the management of hypertensive crises due to its significant toxicities and/or adverse effects 3.
- In patients with severely elevated systolic blood pressure without acute end-organ damage (hypertensive urgency), oral antihypertensive agents can be used to gradually reduce blood pressure 3.
- Combination therapy with multiple antihypertensive agents may be necessary to achieve adequate blood pressure control, with the choice of agents depending on the patient's clinical profile and comorbidities 4, 5, 6.
- The goal of treatment is to safely reduce blood pressure to a target level, which may vary depending on the patient's underlying conditions, such as diabetes or renal disease 7, 6.
Choice of Antihypertensive Agents
The selection of additional antihypertensive agents to be used in conjunction with Hydralazine should be based on the patient's specific needs and clinical presentation.
- Rapid-acting intravenous antihypertensive agents, such as labetalol, esmolol, fenoldopam, nicardipine, and clevidipine, may be considered for acute blood pressure reduction in hypertensive emergencies 3.
- Oral antihypertensive agents, including thiazide diuretics, calcium channel blockers, angiotensin-converting enzyme inhibitors (ACEIs), and angiotensin receptor blockers (ARBs), can be used for the management of hypertensive urgency and for long-term blood pressure control 4, 5, 6.