Am Experiencing Low Blood Pressure And Light-headiness And Somewhat Dizzy.

Am experiencing low blood pressure and light-headiness and somewhat dizzy. Am concerned could have been cause from drug interaction. Due to a severe coughing session and sinus drainage, took about a tablespoon of Cheratussin AC syrup, along with a capsule of benzonatate, 1 Claritin tablet. About an hour later high blood pressure medication, 20 mg losartan and an hour later an ambien. This was all taken between 9pm and midnight last night and am experiencing the low blood pressure symptoms - took pressure around noon and was 77/45.