The bloodshot appearance is due to the irritation and dilation of the surface blood vessel in the eye. Other symptoms can accompany the red appearance, like itching, soreness, discharge and even blurred vision. These symptoms could indicate a more serious problem.
The list of possible medications or substances mentioned in sources as possibe causes of Heart block includes: 1  Beta-adrenergic blockers. 2  Digitalis. 3  Flecainide. Flecatab. 4  Flumadine. Quinidine. 5  Rimantidine. Tambocor.
Some medications can also cause low blood pressure, including diuretics (water pills), alpha blockers, beta blockers, drugs for Parkinson's disease, certain types of antidepressants, and sildenafil (Viagra), particularly in combination with the heart medication nitroglycerine.