Hypertensive emergency agents

Hypertensive emergency agents

Drug monograph · NCLEX study reference
Therapeutic class	Antihypertensive (emergency)
Pharmacologic class	Alpha-beta blocker, calcium channel blocker, direct vasodilator (nitroprusside), arteriolar vasodilator (hydralazine)
Onset / peak / duration	IV onset within minutes; nitroprusside immediate and very short.
Half-life / level	Nitroprusside very short (titratable infusion).
Routes	IV
High-alert (ISMP)	No
Black box warning	Yes (see Safety)
Antidote / reversal	Hydroxocobalamin or sodium thiosulfate for cyanide toxicity; supportive care.
Pregnancy / lactation	Labetalol and hydralazine and nicardipine used in pregnancy.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Hypertensive emergency agents — Antihypertensive (emergency); Alpha-beta blocker, calcium channel blocker, direct vasodilator (nitroprusside), arteriolar vasodilator (hydralazine).

Identification

• Therapeutic class: Antihypertensive (emergency).
• Pharmacologic class: Alpha-beta blocker, calcium channel blocker, direct vasodilator (nitroprusside), arteriolar vasodilator (hydralazine).

Pharmacology

• Mechanism of action: Rapidly lower blood pressure by blocking adrenergic receptors, blocking calcium channels, or directly relaxing vessels.
• Onset / peak / duration: IV onset within minutes; nitroprusside immediate and very short.
• Half-life / therapeutic level: Nitroprusside very short (titratable infusion).

Clinical use

• Indications: Hypertensive emergency and urgency.
• Usual dose, route, frequency: IV bolus or titrated infusion with continuous monitoring.
• Maximum dose / adjustments: Lower blood pressure gradually (not too fast); nitroprusside duration limited by cyanide and thiocyanate accumulation.

Safety

• Contraindications: Labetalol in asthma and bradycardia; nitroprusside caution in renal and hepatic impairment.
• Black box warning: Sodium nitroprusside carries a boxed warning that it can cause precipitous, excessive blood pressure drops and cyanide toxicity; use with continuous monitoring and dose limits.
• Interactions: Other antihypertensives (additive), nitroprusside accumulates cyanide.
• Pregnancy / lactation: Labetalol and hydralazine and nicardipine used in pregnancy.
• High-alert: No.

Adverse effects

• Common side effects: Hypotension, headache, reflex tachycardia (vasodilators).
• Serious effects to report: Excessive blood pressure drop, cyanide toxicity signs (nitroprusside: confusion, metabolic acidosis), reflex tachycardia.
• Antidote / reversal: Hydroxocobalamin or sodium thiosulfate for cyanide toxicity; supportive care.

Nursing process

• Assessment before administration: Blood pressure, target reduction goal, arterial line if available, renal and hepatic function (nitroprusside).
• Interventions during therapy: Continuous blood pressure monitoring; lower pressure gradually; protect nitroprusside from light and limit duration.
• Monitor: Blood pressure continuously, neuro status, acid-base (nitroprusside).
• Evaluation / expected outcome: Controlled, gradual blood pressure reduction.

Patient teaching

• Patient teaching: Critical care setting; team manages.
• Notify provider if: Not applicable (monitored setting).
• Administration tips: Continuous monitoring; protect nitroprusside from light; gradual reduction.