Angiotensin II receptor antagonists (like losartan) have the same effect as ACE inhibitors, with less risk of side effects. The downside is that they're more expensive because they're newer.
This is why it is generally a good idea to try ACE inhibitors first, then switch for Losartan if you get side effects from them.
BTW, you mean 150/90 (mmHg) for your BP.