The American Heart Association warns, always read the labels on over-the-counter decongestants if you have high blood pressure or are being treated for it. Those with high blood pressure, or HBP, readings of 120/80 mm Hg are particularly susceptible to ingredients in over-the-counter decongestants. It adds that prescription HBP drugs may also be vulnerable to these ingredients decreasing their effectiveness. There are some over-the-counter, or OTC, drugs that have a decongestant effect and are safe to use with HBP.
The Harvard Medical School Family Health Guide lists several OTC medications, all of which are antihistamines, that can be taken with HBP. Antihistamines block the action of histamines at the receptor level. They dry up mucus membranes, making them effective as decongestants for those with HBP. The University of Pittsburgh at Bradford cites that antihistamines may reduce the reaction between the virus causing the congestion and the local tissues. OTC antihistamines include Benydryl, Chlor-Trimeton and Claritin.
The pharmaceutical company Schering-Plough is an official sponsor of the American Heart Association and has developed a line of OTC remedies that do not affect blood pressure but provide decongestant relief. These include Coricidin HBP Cough and Cold, Coricidin HBP Cold and Flu, Coricidin HBP Maximum Strength Flu, Coricidin HBP Chest Congestion and Cough, Coricidin HBP Nighttime Multi-Symptom Cold and Coricidin HBP Day and Night Multi-Symptom Cold. Ingredients common to most of them are chlorpheniramine maleate, dextromethorphan hydrobromide, guaifenesin and acetaminophen.
The University of Pittsburgh at Bradford explains that during a cold, a virus causes nasal passages to swell, which creates congestion and stuffiness and increases the production of mucus. This can affect breathing, tasting and smelling. It recommends doubling or tripling the daily fluid intake, inhaling steam from a vaporizer or hot pan of water to loosen mucus and drinking a salty liquid like chicken soup as natural ways to deal with symptoms of congestion.