Q. I’m immunocompromised and take medication for high blood pressure, irregular heartbeat and cholesterol. I tested positive for COVID-19 and the flu while traveling to California. Probably the plane trip was the culprit.

I’ve had all my shots, but due to my condition, I don’t make antibodies easily. The urgent care physician prescribed Paxlovid and Tamiflu. She took me off all my medications to avoid drug interactions.

The medicines worked. Within three days, all symptoms except exhaustion were gone. The fatigue lasted a few more weeks and I tested positive for 20 days from start to finish.

A. Antiviral medications can make a difference for both COVID-19 (Paxlovid) and influenza (Tamiflu, oseltamivir).

There are other prescription antivirals to treat the flu. Xofluza (baloxavir) is a single-dose treatment that can also be used for prevention. It’s expensive, though, with the price running anywhere from $170 to $250.

One other option is Relenza (zanamivir). This inhaled medication may also shorten the duration of flu symptoms, possibly faster than Tamiflu (JAMA Network Open, Aug. 2, 2021).

Q. When I was first prescribed metformin, I didn’t notice any side effects. Before long, though, I started having diarrhea every day, and I couldn’t leave the house after taking my pill each morning.

If I go out shopping, I constantly mess up my clothes because I get a sharp pain, and within three minutes or less, I have to find a bathroom. I must carry extra undergarments, wipes, etc.

This gets old very fast. Also, I worry about losing potassium and other electrolytes through diarrhea. My doctor doesn’t seem concerned about it, though. What alternatives are there for treating Type 2 diabetes?

A. Metformin has long been a first-line medication for Type 2 diabetes, but it is certainly not the only drug that can help control blood sugar. Ask your doctor whether sitagliptin or liraglutide might be an option.

There are also other drugs in each of those categories. You have heard, for example, of semaglutide under the brand name Ozempic. Doctors also prescribe drugs such as canagliflozin (Invokana), dapagliflozin (Farxiga) and empagliflozin (Jardiance).

All of these blood sugar drugs work best in combination with diet and exercise.

In preparing for the conversation with your physician, you may wish to consult our “eGuide to Preventing & Treating Diabetes.” In it, we discuss the pros and cons of the medications as well as diet, herbs and nondrug approaches to blood sugar control. This online resource may be found under the Health eGuides tab at www.PeoplesPharmacy.com.

Q. I started taking Zyrtec for allergies and find it is incredibly difficult to stop.

Within 48 hours of not taking a pill, my entire body slowly but surely becomes unbearably itchy. It impacts my day-to-day life.

The itching disappears like magic as soon as I take another pill. There needs to be more information on this available to the public, given the popularity of this common over-the-counter antihistamine.

A. We completely agree. After badgering the Food and Drug Administration about this problem for years, the agency finally added information about withdrawal itching (they call it rebound pruritus) to the prescribing information for cetirizine (Zyrtec) and levocetirizine (Xyzal) in 2017. Doctors reading that information before writing a prescription might heed the warning. As far as we can tell, though, the OTC packaging does not warn patients about this possibility.

In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of King Features, 300 W. 57th Street, 41st Floor, New York, NY 10019, or email them via their website: www.PeoplesPharmacy.com. Their newest book is “Top Screwups Doctors Make and How to Avoid Them.”