Dear Dr. Roach: I have found what seems like an almost-magical way to stop the progression of the common cold and a cure for it. I am a reasonably healthy 84-year-old male with a medically sound lifestyle. Historically, I have gotten about two common colds per year that always starts with nasal congestion. It rapidly progresses to a runny nose, sneezing, a sore or scratchy throat, coughing up green mucus, a low-grade fever, and a general feeling of malaise, all of which lasts for about eight days.

Recently, I have found that if I take a Claritin-D when the nasal symptoms first start, it dries me out. My nose opens up, and it never progresses into any of the more unpleasant symptoms. My surmise is this: There is a causal relationship between the nasal congestion and the cold symptoms, and by eliminating the nasal congestion symptoms, I block the progression.

I would appreciate your comments.

— G.P.

Answer: Sadly, this isn’t a cure for a virus; it’s just a way of reducing symptoms. Americans spend a great deal on treatments to reduce symptoms from colds with variable success, but you have found a treatment that works for you. Claritin-D is a combination of an antihistamine and a decongestant. (The “-D” is for decongestant, specifically pseudoephedrine.) Although these help with symptoms, only your body’s immune system will get rid of the virus, which takes at least a few days. (Eight isn’t out of the range.)

I do worry about giving men in their 80s a decongestant. I once sent a patient to the emergency room by prescribing him a decongestant, which affected his prostate so much that he couldn’t urinate at all. His situation required a tube for a few days, and he was understandably not happy with me. (It was also the last time I prescribed this drug without warning.)

So, while I’m glad Claritin-D works great for you, it doesn’t work well for most people. It can also cause serious side effects in a few and doesn’t make your body get rid of the virus any faster.

Dear Dr. Roach: I am on a low-sodium diet by choice. I do not add salt to anything, except when I bake for others. I have found that if I cut salt down or eliminate it, I can also reduce my sugar levels as well.

After I read a recent article on potassium and sodium, I stopped eating sandwich meats (except for tuna fish), pizza, and oatmeal from flavored packets. I also reduced my intake of fast food and restaurant meals, and I increased my potassium intake with high-potassium foods.

The recommended dietary allowance (RDA) on sodium is 2,300 mg, while the RDA on potassium is 4,700 mg: these two should be in a 2:1 ratio ideally. Am I correct?

— A.H.

Answer: It is absolutely true that most North Americans consume too much sodium and too little potassium. A typical American diet consists of 3,400 mg of sodium and 2,500 mg of potassium.

Most of my patients do not want to carefully monitor the potassium and sodium content of their food. Furthermore, I wouldn’t say that there is a particular ratio you are looking to get, but you are quite right that there are guidelines recommending no more than 2,300 mg sodium and at least 4,700 mg of potassium.

You’ve made a lot of good choices. You can certainly count your potassium and sodium intake if you want, but you are looking to consume a lot more potassium than sodium. The exact amount isn’t as important as choosing foods you like that are healthy.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.