My husband ,who is 89 years old and on several medications for hi...

My husband ,who is 89 years old and on several medications for his heart and blood pressure, and inhalers for breathing plus uses a nebulizer, has been taking singulair for 3 weeks and his blood pressure has been very high since, higher than his normal. Since singulair"s main ingredient is(montelukast) SODIUM could this be the cause of elevation of his blood pressure? I am very concerned. WOULD APPRECIATE YOUR RESPONSE. Thank you. Aurica ***