Cortis,
Thanks for your question. Lotrel is a combination medication composed of a calcium channel blocker and an ACE inhibitor. The toprol is a beta blocker. This combination of medications works very well to control blood pressure. If your pressure drops too much, one of the possible symptoms is dizziness. It sounds like your doctor is keeping an eye on your pressure and has ruled out this possibility. The eye movements associated with your computer activity causing your symptoms does make your inner ear a suspect cause.
The above medications themselves are not known to cause any inner ear problem and an ENT evaluation sounds like the next step in your evaluation. In most people this is usually a temporary problem. The ENT specialist will hopefully shed more light on the situation. Don't be surprised if he asks for further studies to test your hearing, balance mechanism, and even an MRI of the brain.
Feel better.
Martin Cane, M.D.