Papaverine HCL / Phentolamine Mesylate (BiMix)

What is Papaverine HCL / Phentolamine Mesylate?

Papaverine and phentolamine, administered together as a BiMix injection or Bi‑Mix injection, work synergistically to relax penile smooth muscle and enhance localized vasodilation. Papaverine functions as a non‑selective phosphodiesterase inhibitor that increases intracellular cAMP and cGMP, producing broad smooth‑muscle relaxation independent of nerve input. Phentolamine complements this effect by blocking both alpha‑1 and alpha‑2 adrenergic receptors, preventing catecholamine‑driven vasoconstriction and briefly countering circulating epinephrine and norepinephrine, while also creating mild increases in heart contractility and rate through presynaptic alpha‑2 blockade. Together, these actions support more effective cavernosal smooth‑muscle relaxation and promote tumescence through increased blood flow.