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Your Good Health: Benefits claimed for CBD, but where is the evidence?

Dear Dr. Roach: I have a friend whose daughter has an egg allergy. She said her daughter will break out in a rash if she eats anything that even has trace amounts of egg in it.
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Dr. Keith Roach writes a medical question-and-answer column weekdays.

Dear Dr. Roach: I have a friend whose daughter has an egg allergy. She said her daughter will break out in a rash if she eats anything that even has trace amounts of egg in it. Another friend of hers told her to use CBD oil to prevent reactions, but I am skeptical. I cannot find anything credible to support the claim. What are your thoughts?

E.B.P.

Almost every day I hear another claim that cannabidiol, the major nonpsychoactive component of cannabis, is effective for some medical condition. Unfortunately, the evidence of effectiveness of CBD is very limited.

The sole U.S. Food and Drug Administration indication for CBD is for the treatment of two uncommon childhood seizures: Dravet syndrome and Lennox-Gastaut syndrome. There is preliminary evidence that CBD may be useful for anxiety disorders, some types of sleep disorders and chronic pain.

There is active research on other conditions, including asthma, multiple sclerosis and contact dermatitis. I believe it is likely that CBD will be proven effective for other conditions, but until there is better evidence of effectiveness, I cannot make a recommendation to use CBD (outside of the two forms of childhood epilepsy for which it is indicated).

Although there are laws in all 50 states legalizing CBD, the U.S. federal government’s position is still that cannabis extracts are Schedule I controlled substances, although they do not seem to be enforcing action against CBD at present. Unfortunately, independent laboratory analysis of available CBD products show that about a quarter of them have less CBD than advertised, and another quarter contained the psychoactive component THC.

Allergies have a broad range of severity in children, from mild rash to life-threatening airway swelling and anaphylaxis. Although many children outgrow egg allergies, your friend should listen to her daughter’s doctor, not her CBD-supporting friend.

Dear Dr. Roach: Is there any good way to find the correct blood pressure medicine that doesn’t suck the life pep out of you, give you a headache, make you short of breath when walking or grapple with all of those side effects at once? Who should manage that program, your regular doctor or your cardiologist? Is there another specialist with the right insight and expertise?

E.M.

Choosing the best blood pressure medicine for a person with high blood pressure starts with knowing as much as possible about the person’s heart and blood vessels, and their other medical conditions.

A person with blockages in the arteries should be on a beta blocker and ACE inhibitor most of the time. A person with diabetes should be on an ACE inhibitor or angiotensin receptor blocker.

An older person with isolated high systolic pressure may get most benefit from a diuretic. However, it may still take some trial and error to find the best choice. Most people are able to find a blood-pressure regimen that has very few side effects.

Most generalists have expertise in blood pressure medications, and are likely to know all your conditions. Cardiologists have more expertise in cardiovascular disease, and I refer to high-blood- pressure experts when I have difficulty getting someone’s blood pressure under control.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers can email questions to ToYourGoodHealth@med.cornell.edu.