 [ Symptoms ] can you take alka seltzer plus for a cold along with benadryl and tylenol for a headache [ Disease ] you could but it might make you very drowsy because both benadryl and alka seltzer plus cold do that there is not any interaction with the tylenol though the alka seltzer plus cold has aspirin in it you would be taking 2 pain relievers and 2 antihistamines alka seltzer plus cold effervescent tablets sparkling original has aspirin pain reliever fever reducer chlorpheniramine maleate antihistamine phenylephrine bitartratenasal decongestant here is what i found in the interaction checker <link> significant   monitor closely potential for interaction alka seltzer plus cold oral + benadryl allergy oral benadryl allergy oral increases and alka seltzer plus cold oral decreases sedation and drowsiness significant   monitor closely potential for interaction alka seltzer plus cold oral + benadryl allergy oral alka seltzer plus cold oral and benadryl allergy oral both increase sedation and drowsiness