What can I take to loose weight that does not affect my blood pressure?

Eat less, alli. If you feel you must take something, Alli is available over the counter and helps with weight loss without affecting bp. Consulting with your doctor first is advisable before you undertake a weight loss program if you have high blood pressure.
No drugs if possible. Try to avoid any agents that specifically run the risk of raising blood pressure, e.g., amphetamine related agents, which may be available over the counter. Although the fda has approved some weight loss meds, long term efficacy has not been stellar. Best is what we refer to as the elf diet (eat less food), best implemented by portion control. Avoid meds if possible ("easy" rx is not the best").