Q. We have heard we should disinfect doorknobs and other things that might have become contaminated with the coronavirus. All the disinfectant wipes and sprays disappeared from grocery shelves a few weeks ago. Is it true you can use a bleach solution? How would you do that?

A. The Centers for Disease Control and Prevention has offered advice on disinfecting cabinet pulls, light switches, doorknobs, faucet handles and other frequently touched objects at home. Clean the surface first with ordinary soap and water. Then disinfect with a freshly made bleach solution. The proper ratio is 5 tablespoons bleach per gallon of water, or 4 teaspoons bleach per quart.

Be sure to wear gloves to protect your hands while cleaning. If the gloves are not disposable, wash them well before removing them. Then wash your hands.

Also, do not use bleach solution on your clothes, rugs, curtains or upholstery. It could ruin them. Instead, wash sheets or clothing on the warmest setting indicated on the label. Use gloves to handle soiled items, and wash your hands thoroughly (20 seconds) after removing the gloves.

One reader also asked: “When you spray that bleach solution on a doorknob, how long should you leave it on?” You should scrub the item, wet it with disinfectant and then let it dry on its own. Don’t wipe the solution off.

Q. I am 68 and live in a senior apartment community. I have a lot of arthritis, and, until recently, I have been attending an in-house exercise class. Three days a week, a professional instructor led us seniors in aerobics, balance and weight training. This has kept me alive. Sadly, the class is now canceled because of social distancing. I don’t know how I will manage my joint pain. Do you have any suggestions?

A. You definitely will want to maintain as much of your exercise routine as you can in your apartment. Exercise helps maintain range of motion. Resistance bands can be ordered online and might be useful.

We suggest several nondrug therapies in our eGuide to Alternatives for Arthritis. They include Knox gelatin in yogurt, a vinegar-juice combination, pineapple extract (bromelain) and herbs such as ashwagandha, boswellia, ginger and turmeric (curcumin).

Dietary supplements such as MSM and SAMe also might be helpful. All are available online. For more details, you can look for Alternatives for Arthritis in the Health eGuide section at peoplespharmacy.com.

Q. I have lupus and have taken hydroxychloroquine for nearly 20 years to manage the symptoms. I have less than a week’s supply and am scrambling to get my next refill. I’m very worried. Many people hope this medication will work to treat coronavirus, and that is causing problems.

I beg those who have neither lupus nor another condition managed by HCQ not to fill prescriptions unless they need them for illness. They are taking lifesaving medications out of circulation for those who need them and for whom HCQ is a reliable treatment.

A. Medical experts have been cautious about the idea that the old malaria drugs chloroquine or HCQ might be used to treat COVID-19. Pilot studies have produced mixed results.

Shortages have appeared because of national publicity. That means patients with rheumatoid arthritis and other autoimmune conditions like lupus are having trouble refilling their prescriptions. Drug companies are ramping up production, but that could take weeks. In the meantime, we hope that patients in need, such as yourself, will get first priority from pharmacists.