A 42-year-old woman complains of severe pulsing headache in the frontoparietal area, vertigo, palpitations. She has been suffering from hypertension for 3 years. Significant increase of BP occurs 2-3 times per month and lasts for 3-8 hours. The left ventricle is enlarged, heart sounds are clear, heart rate - 105/min., BP- 225/115 mm Hg. ECG: signs of left ventricular hypertrophy. What drug would be the most effective for termination of cerebral crisis attack?