<prompt> Which of the following is a K Channel OpenerVerapamilNicorandilRanolazineLignocaine  <response>: Nicorandil Nicorandil is a niacinamide derivative - used as a second line anti-anginal drug - Its mechanism of action involves opening ATP sensitive K channels and by mediating nitrovasodilation. Apa from the anticipated nitrates like side effect of Headache, Nicorandil can cause serious adverse effects involving ulceration of skin, mucous membrane, eyes and the gastrointestinal tract. Contraindications to Nicorandil:- Absolute CI:- Patients with hypovolaemia, cardiogenic shock or acute pulmonary edema Patients on Sildenafil PDE-5 inhibitor , Riociguat soluble guanylate cyclase stimulator Relative CI or Cautious use in: - Patients with NYHA IIIIV Hea Failure G6PD deficiency risk of methhemoglobinaemia Patients taking Dapoxetine risk of ohostatic hypotension Patients with renal dysfunction and drugs causing hyperkalemia Ref:- KD Tripathis Essentials of Medical Pharmacology 8th Ed; Pg Num:- 585 