Because of spam, I personally moderate all comments left on my blog. However, because of health issues, I will not be able to do so in the future.

If you have a personal question about LI or any related topic you can send me an email at I will try to respond.

Otherwise, this blog is now a legacy site, meaning that I am not updating it any longer. The basic information about LI is still sound. However, product information and weblinks may be out of date.

In addition, my old website, Planet Lactose, has been taken down because of the age of the information. Unfortunately, that means links to the site on this blog will no longer work.

For quick offline reference, you can purchase Planet Lactose: The Best of the Blog as an ebook on or Almost 100,000 words on LI, allergies, milk products, milk-free products, and the genetics of intolerance, along with large helpings of the weirdness that is the Net.

Monday, March 17, 2008

More on the Use of Lactose in Medications

I've posted numerous times about the frequent presence of lactose as a filler, binder, or coating for pills, whether prescription or over-the-counter (OTC). The fullest discussion was probably in Lactose in Medications.

Whether a pill's formulation uses lactose or not is just one of the possible variations that might affect your response to a drug, an issue that Melissa Healy, a staff writer for the Los Angeles Times, reports is not as well regulated by the Food and Drug Administration (FDA) as it should be.

In fact, a brand-name drug's generic counterpart is rarely an exact replica. Though the two share equal amounts of the same active ingredient, they generally look different. And those differences, say some pharmacologists, can result in small variations in how they work in patients.

A brand-name drug and its generic in most cases are formulated with different colorants, fillers and binding materials. Though all of those must come from an FDA-approved list of pharmaceutical ingredients, they are, in most cases, assembled differently in each manufacturer's product. One version of a drug might use lactose or sugar as an inactive ingredient; another might not. But incidental ingredients like these can affect the way patients dissolve and metabolize a drug's active ingredient -- faster or slower. And that, in turn, can result in variations in the two formulations' effects.

In almost all cases, the FDA permits a generic drug to release 80% to 125% of an active ingredient into the bloodstream, compared to that released in a single dose of the original medication. That range would make little practical difference in the effect that most drugs have. And the FDA and generics manufacturers defend the allowable range of variance as the same that is permitted among "batches" of brand-name drugs.

But medical and pharmacology specialists warn that the FDA's range may be too broad for some drugs, especially in cases where a drug has a "narrow therapeutic index" -- the fine line between an ineffective dose and a dangerous one.

Both doctors and pharmacists have guides that spell out the inactive ingredients for every prescription medication. As I mentioned in the linked post, they've been able to do a quick lookup of prescriptions drugs containing lactose for a long time.

But as I also mention there, a simple lookup of drug names that contain lactose fails to answer all the needed questions. The situation is much worse when generic drugs are involved and worse yet for over-the-counter medications. Discovering the use of lactose for a specific type, size, strength, and variety of pill is normally simple. Discovering whether any variation of the needed medication, in any guise from any manufacturer, contains lactose is sometimes next to impossible.

You need to start with your doctors and make sure they are aware of any concerns you have. You also need to be aware that you probably need to have few concerns. Few if any sufferers of lactose intolerance are so sensitive that they will react to the lactose in any one pill. I have found no medical journal articles that reported any allergic reaction caused by taking a pill containing lactose. (However, there are at least two known Allergic Reactions from Lactose in Dry Powder Asthma Inhalers.)

The use of lactose in so common that avoiding it may limit your choices - and your doctors' choices - unacceptably. If you feel you must do so, do so wisely and knowingly and be sure to thoroughly examine all the alternatives.

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1 comment:

Anonymous said...

I am older and just found your wonderful site! Many thanks!!!

A few years ago I had always wondered why Claritin gave me gas and loose stools and cramps as if I had eaten some cheese (lactose intolerant most all my life). I asked the Pharmacist for a list of ingredients and was shocked to find Lactose. She told me it was a very common filler. I had to change to a different allergy med. Now I always ask before filling an Rx. After reading on your site, I must be fairly severe. I just do without!