Na⁺-K⁺ ATPase is located in the plasma membrane with ATP site on cytosolic side. For each ATP consumed, 3Na⁺ go out of the cell (pump phosphorylated) and 2K⁺ come into the cell (pump dephosphorylated).Plasma membrane is an asymmetric lipid bilayer containing cholesterol, phospholipids, sphingolipids, glycolipids, and proteins.

Ouabain (a cardiac glycoside) inhibits by binding to K⁺ site.

Cardiac glycosides (digoxin and digitoxin) directly inhibit the Na⁺-K⁺ ATPase, which leads to indirect inhibition of Na⁺/Ca²⁺ exchange → ↑ [Ca²⁺]_i → ↑ cardiac contractility.