How to manage hypotension secondary to antihypertensive medication overdose?

Management of Hypotension Secondary to Antihypertensive Overdose

Immediate management of antihypertensive overdose-induced hypotension requires aggressive fluid resuscitation with normal saline boluses (10-20 mL/kg), followed by vasopressor support with norepinephrine or epinephrine if hypotension persists, while simultaneously identifying the specific drug class to guide targeted antidote therapy. 1

Initial Stabilization and Supportive Care

Fluid Resuscitation

• Administer normal saline boluses of 10-20 mL/kg as first-line therapy for hypotension. 1 Small boluses (5-10 mL/kg) may be preferable in calcium channel blocker overdose due to myocardial depression limiting fluid tolerance. 1
• Monitor carefully for fluid overload, particularly in patients with underlying cardiac dysfunction. 1

Vasopressor Selection

• If hypotension persists after fluid resuscitation, epinephrine and norepinephrine are superior to dopamine for raising blood pressure in antihypertensive overdose. 1
• Phenylephrine (1-10 mcg/kg/min) or dopamine (5-15 mcg/kg/min) are alternative options but less effective. 1
• High-dose epinephrine infusions may be particularly effective in beta-blocker overdose. 1

Drug-Specific Antidote Therapy

Calcium Channel Blocker Overdose

High-dose insulin-euglycemia therapy is the most effective treatment for calcium channel blocker-induced hypotension refractory to standard measures. 1

High-Dose Insulin Protocol

• Administer 1 U/kg regular insulin IV bolus with 0.5 g/kg dextrose, followed by continuous infusions of 0.5-1 U/kg/hour insulin and 0.5 g/kg/hour dextrose. 1
• Titrate insulin infusion to achieve adequate hemodynamic response. 1
• Titrate dextrose to maintain serum glucose 100-250 mg/dL (5.5-14 mmol/L). 1
• Monitor serum glucose every 15 minutes initially during dextrose titration. 1
• Target potassium levels of 2.5-2.8 mEq/L to avoid overly aggressive repletion (which can cause asystole). 1

Calcium Administration

• Consider calcium in patients with shock refractory to other measures (Class IIb recommendation). 1
• Administer 0.3 mEq/kg calcium (0.6 mL/kg of 10% calcium gluconate or 0.2 mL/kg of 10% calcium chloride) IV over 5-10 minutes. 1
• Follow with infusion of 0.3 mEq/kg/hour, titrated to hemodynamic response. 1
• Monitor serum ionized calcium levels; avoid severe hypercalcemia (>2× upper limit of normal). 1
• Calcium chloride requires central venous access for sustained infusions; peripheral infiltration causes severe tissue injury. 1

Beta-Blocker Overdose

High-dose insulin-euglycemia therapy using the same protocol as calcium channel blocker overdose is recommended for refractory beta-blocker-induced hypotension. 1

Glucagon Therapy

• Consider glucagon for beta-blocker overdose (Class IIb recommendation). 1
• Administer 5-10 mg IV over several minutes, followed by infusion of 1-5 mg/hour. 1
• Assist ventilation if significant respiratory compromise develops (tachypnea, respiratory distress). 1

Calcium Administration

• Calcium may be helpful in beta-blocker overdose using the same dosing as for calcium channel blockers. 1

ACE Inhibitor/ARB Overdose

• No specific antidotes exist; management relies on aggressive fluid resuscitation and vasopressor support. 1
• Vasopressors (norepinephrine, epinephrine) are essential for persistent hypotension. 1

Advanced Rescue Therapies

Lipid Emulsion Therapy

• Consider intravenous lipid emulsion for severe, treatment-refractory hypotension from beta-blocker or calcium channel blocker overdose. 1
• Evidence remains limited but case reports suggest potential benefit. 1

Mechanical Circulatory Support

• For patients remaining critically hypotensive despite maximal vasopressor therapy, consider intra-aortic balloon counterpulsation, ventricular assist devices, or extracorporeal membrane oxygenation (ECMO). 1
• These interventions may be lifesaving in severe refractory cases. 1

Consultation

• Promptly consult a medical toxicologist or poison control center for treatment-refractory hypotension from antihypertensive overdose. 1

Critical Monitoring Parameters

• Continuous cardiac monitoring and blood pressure measurement (arterial line preferred for vasopressor titration). 1
• Frequent serum glucose monitoring (every 15 minutes initially with insulin therapy). 1
• Serial electrolytes, particularly potassium and ionized calcium. 1
• Neurological assessment for signs of cerebral hypoperfusion. 1
• Urine output and renal function monitoring. 1

Common Pitfalls to Avoid

• Do not use beta-blockers in cocaine-induced hypotension (Class III contraindication). 1
• Avoid excessive fluid administration in calcium channel blocker overdose due to myocardial depression. 1
• Do not aggressively correct hypokalemia during insulin therapy (target 2.5-2.8 mEq/L). 1
• Concentrated dextrose solutions (>10%) require central venous access. 1
• Glucagon has insufficient evidence for calcium channel blocker overdose. 1