Hello!
Decongestants can increase blood pressure and heart rate, especially in older people, who are more susceptible to side effects.
Since there are other effective and safer treatments, I tend to turn to these.
First, keep encouraging nasal hygiene with a saline solution (Hydrasense, Sinus Rinse and others), which can be done as often as necessary during the day, and at least 30 minutes before bedtime. It is the single best treatment. Also encourage her to drink plenty of liquids, cold or hot as per her preferences.
I also find that Vicks Vaporub ointment can help relieve congestion, when applied to the chest at bedtime.
Has she tried other treatments? Are seasonal allergies a possibility? If so, an anti-histamine medication could be tried
If it hasn't already been done, I suggest a rapid COVID test, as a precaution.
I hope I have been useful to you, I will remain available if you have any other questions!
Tom Samaha, pharmacist