Does Guaifenesin raise blood pressure?

It is not listed ass a possible side effect:

Guaifenesin side effects
Get emergency medical help if you have signs of an allergic reaction to guaifenesin: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Common guaifenesin side effects may include:

dizziness, headache;

drowsiness;

rash; or

nausea, vomiting, stomach upset.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

https://www.drugs.com/guaifenesin.html

Do inform your Dr. what you are experiencing.