Can NyQuil/DayQuil be taken if you take Losartan 100mg? If not what recommendations for cold/flu day and night medicines do you have? Thank you!

Mixing medications. Either of them should be fine. The dayquil contains a mild decongestant - phenylephrine which could potentially raise your blood pressure. One version of the nyquil contains pseudoephedrine which should be avoided in people with high blood pressure but in the US that would be behind the counter. I would say take whatever to help your symptoms and only for as long as you have symptoms.