Q: I recently have started using an e-cigarette. It has dramatically cut down my smoking of traditional cigarettes, plus there is no smoke smell or residual on clothing or furniture.

I initially experienced headaches and was told to reduce the nicotine percentage in the liquid. That helped. Are you aware of any other side effects?

A: Electronic cigarettes contain a battery-powered heater to vaporize a nicotine solution so that the nicotine can be inhaled. This avoids some of the other toxins in cigarette smoke, but nicotine itself can have side effects. They include headache, heart-rhythm disturbances and elevated blood pressure.

A preliminary report in JAMA Internal Medicine (online, March 24, 2014) noted that people using e-cigarettes were no more likely to quit smoking than those using traditional cigarettes alone. Nicotine is a powerfully addicting drug.

Q: Insurers require us to use generic drugs. My wife and I both take Ambien when we travel, which is quite often.

If we were buying brand-name Ambien, it would cost us more than $350 out of pocket for 30 pills. Our insurance would not pay a penny.

The generic zolpidem costs $8 to $10 for the same number of pills. We have found that one generic works just like the brand name, but a different maker’s generic doesn’t work at all.

So far, we’ve been able to request the specific maker we prefer from the pharmacy. But we worry that if the pharmacy can’t supply the one that works, we might get no sleep at all on our journeys. Do you have any recommendations about how to deal with this problem?

A: Like hundreds of other readers, you have discovered that generic drugs are not all “identical.” Despite reassurances from the Food and Drug Administration, some generic manufacturers seem to provide better products than others.

Your strategy to request the generic that works for you is sensible. This approach may require planning ahead, since the pharmacy might have to place a special order for you.

We have other tips on using generic drugs wisely and guidelines for buying medicines online in our brochure Saving Money on Medicine. You will also learn how the FDA has relied on the honor system to monitor drug quality. Anyone who would like a copy, please send $3 in check or money order with a long (No. 10), stamped (70 cents), self-addressed envelope to: Graedons’ People’s Pharmacy, No. CA-99, P.O. Box 52027, Durham, NC 27717-2027. It also can be downloaded for $2 from our website: www.peoplespharmacy.com.

Q: Ever since I went on a low-carb diet in 1964 (before Atkins), I have used only whole milk. When the government began advocating a low-fat diet, Americans became obese, because when you remove the fat from a product, you have to add carbs to make it taste better.

My husband is a type 2 diabetic. When he took charge of his diet, he found that by eating very low carb and high fat, his blood lipids improved, and he lost weight. He can keep his blood sugar under control without insulin when he eats very low carb.

A: Contrary to conventional dietary advice, a recent meta-analysis of nutritional studies found no convincing connection between a diet high in saturated fat and an elevated risk of heart disease (Annals of Internal Medicine, March 18, 2014). This finding is controversial, but seems in line with your family’s experience.

Joe and Teresa Graedon answer letters from readers. Email them via their website: www.PeoplesPharmacy.com. Their newest book is “Top Screwups Doctors Make and How to Avoid Them.”