Both drugs can cause excessive sleepiness, so the combination really hit you hard. Also, older people can be more sensitive to those side effects. This is not a side effect that easily goes away. In fact, trazadone is often used to treat insomnia. The persistent drowsiness is very common and many people discontinue these drugs because of it. You don t say what you are taking these for, but you may want to ask your doctor if one or the other is adequate for treatment rather than taking both, or reducing the dose of Trazadone as 150 mg is a pretty strong dose to start with. Hope this helps.