The standard answer is that lactose is a milk-derived sugar and casein is a milk-derived protein. "Intolerance" to casein is an allergy to milk proteins. What are his symptoms?

Some people (not all) who are allergic to milk are also allergic to casein. Some people who are allergic to dairy are also lactose intolerant (lactase deficient). Some are not.

If he has no trouble with lactose, it's highly unlikely (but not totally impossible) that he'll have some trouble with the Singulair. He will not likely have a severe allergic reaction to the lactose in Singulair, simply because it is highly unlikely to contain any dairy proteins. He might ultimately develop a lactose intolerance (I did), but not necessarily.

Our son is highly allergic to milk, and somewhat allergic to casein. He has taken Singulair for a few years now with no adverse effects. He is always fairly itchy, and we're never sure how much if any the Singulair contributes. For him, this small risk is outweighed by the benefit.

If your husband's at all worried, he should talk to his doctor and they should decide whether threre's any plausible risk.

Mark

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> My husband is casein intolerant and was recently given samples of
> Singulair.