Dantrolene, lipid emulsion 20%, sugammadex, vasopressin, nitric oxide
Skeletal muscle ryanodine receptor antagonist
Blocks RYR1 (ryanodine receptor) → ↓ Ca²⁺ release from sarcoplasmic reticulum → muscle relaxation. The only drug for malignant hyperthermia.
Lipid resuscitation agent
Theory: 'Lipid sink' sequesters lipophilic drugs (especially LAs), shifts to better Ca²⁺ handling, fatty acid metabolic support.
Cyanide antidote / NO scavenger
Vitamin B12a precursor; cyanide binds to cobalt center of hydroxocobalamin → forms cyanocobalamin (B12) → renal excretion. Also scavenges nitric oxide → vasoconstriction.
Somatostatin analogue
Long-acting somatostatin analogue → suppresses splanchnic blood flow, GI/pancreatic secretions, GH, glucagon, insulin, and serotonin/vasoactive-peptide release.
Peripherally-acting mu-opioid receptor antagonist (PAMORA)
Blocks GI mu-opioid receptors WITHOUT crossing the blood-brain barrier → reverses opioid-induced gut slowing while preserving central analgesia. Accelerates return of bowel function.
Non-selective alpha-adrenergic antagonist
Competitive, reversible α1 + α2 blockade → vasodilation. Short-acting.
Selective pulmonary vasodilator (inhaled gas)
Inhaled NO diffuses to pulmonary vascular smooth muscle → ↑ cGMP → SELECTIVE pulmonary vasodilation only in VENTILATED lung units (improves V/Q matching). Inactivated by hemoglobin before reaching systemic circulation → no systemic hypotension.
Antidote — antidigoxin antibody fragment
Ovine Fab fragments bind free digoxin → the complex is renally excreted → rapidly reverses digoxin/digitoxin toxicity.
Methylxanthine bronchodilator + adenosine antagonist
Nonselective PDE inhibition (↑ cAMP) + adenosine-receptor antagonism → bronchodilation, respiratory stimulation, mild inotropy/chronotropy.
Proton pump inhibitor
Irreversibly inhibits the gastric H⁺/K⁺-ATPase (proton pump) → ↓ gastric acid secretion + volume.