Hello, Welcome to Just Answer and thanks for your question. None of the stimulant medications like Phentramin or phentermine is safe to take if someone has blood pressure issues. The only safe drug to take is prescription orlistat or its sister lower-dose over-the-counter version sold as Alli. It eliminates a portion of the fats that are eaten. The trick is that you have to eat a low-fat diet. If you don't, it will cause oily flatulence and perhaps fecal incontinence.
Weight loss is accomplished by taking in fewer calories than one uses in exercise and metabolism. Meanwhile, below are links to some typical lower calorie diets that can help. It is important to weigh and measure foods for a while to make sure the portions are the same ones called for in the diets. Choosing high fiber foods will keep you from being hungry between meals.