Is reaction to quinine genetic?

Q. Warning bells went off for me when I read your column about taking quinine for leg cramps. In 1983, my father was given quinidine for a heart arrhythmia. He started bleeding internally as a result of the drug. The bleeding was irreversible, and he died shortly afterward.

I discussed it with my internist, and his first question to me was: “Do you drink any mixed drinks with tonic water?” I do not. I have reminded my children about a possible reaction to quinine.

A. You are very wise to be wary of quinine in tonic or medicines. Some people are genetically predisposed to severe adverse reactions to the heart drug quinidine and its close cousin quinine.

Many years ago, a reader shared this frightening experience: “One evening I drank 5 ounces of tonic water; the next morning I was in the emergency room with a frightening skin reaction. I was hospitalized for many days.

“My platelet count dropped to 1,000. Now it has gradually come back up to 266,000. I was diagnosed with ITP (idiopathic thrombocytopenic purpura), triggered by the quinine in the water. It nearly killed me.”

The Food and Drug Administration banned the use of quinine to treat muscle cramps because it can cause a life-threatening blood disorder. The agency allows quinine in tonic water, however. People who are susceptible to dangerous reactions must avoid this beverage.

Q. I survived flu season without getting sick, but now I have a terrible sore throat and am starting to cough. I hate the taste of DM (dextromethorphan) cough medicines. What else can you recommend?

A. Flu season is almost over, but some people are still suffering. You may want to get a rapid flu test to rule this out.

If you have a cold, there are several home remedies to control a cough. One is onion syrup. The onion is sliced thin and simmered in sweetened water until it is quite soft. Many readers assure us that it is delicious.

To calm a cough at night, you might try smearing Vicks VapoRub on the soles of the feet before bedtime. Put on thick socks to keep the goo off your sheets.

Q. I am curious to know about the health benefits of hibiscus tea. I’ve heard that it’s good for blood pressure. If so, how do you make it and how much do you drink?

A. Hibiscus (Hibiscus sabdariffa) is a bush with lovely bright-red flowers. The dried petals can be used to make a pleasantly tart-tasting tea.

This tea has been used in folk medicine to treat a variety of problems, and scientists have confirmed that it lowers blood pressure as well as cholesterol (Journal of Clinical Pharmacy and Therapeutics, December 2017; Indian Journal of Pharmacology, September-October 2015).

Another reader shared this experience: “I had high blood pressure and brought my blood pressure down from 170/90 to 140/80 with just hibiscus tea in about six weeks. For every flower, I use 100 ml of hot water. I add lemon juice after steeping the flowers for approximately half an hour; then I strain the tea. I add honey or sugar to taste. I drink 150 ml three times a day.”