In Search of Lactose

Abstract

Objective:

To describe lactose in medications, answer commonly asked questions about lactose intolerance, and to provide useful information to pharmacists on how to identify lactose content in medications.

Design:

Descriptive.

Summary:

Within the population of lactose-intolerant individuals, a wide variation exists concerning the degree to which the lactase enzyme is deficient. When asked whether lactose-intolerant individuals can take their lactose-containing product without complications, the surveyed drug manufacturers offered a number of suggestions, including the following: avoid the product; determine the patient's level of lactose intolerance and, depending on the severity of the condition, decide with the physician whether the medication should be taken or whether it can be substituted with a suitable formulation that does not contain lactose; and supplement each dosage with an exogenous lactase enzyme. Because drug manufacturers themselves acknowledge that even minute amounts of lactose in medications may be a problem for those who are severely intolerant of lactose, this agent may not be the ideal filler, as it is described in standard pharmacologic references. Although the original intent was to develop a comprehensive list of lactose-containing and lactose-free drugs, that proved to be an unmanageable task. Instead, from a literature search and primary investigation, information and discussion are provided in a question/answer format that is designed to help clinicians serve their lactose-intolerant patients.

Conclusions:

Primary healthcare professionals should be aware of the potential effects of lactose, not only in foods, but also in medications. If patients experience diarrhea, cramping, or bloating, or if babies become colicky for no medically apparent reason, a search for lactose content in medications or in infant formulas may reveal the cause. However, medical evaluation is always appropriate, as a small percentage of such patients may in fact have an underlying intestinal disease to which lactose intolerance is secondary. Because drug manufacturers acknowledge that even minute amounts of lactose in medications may be a problem for those who are severely intolerant of lactose, this agent may not be the ideal filler. A worthy subject for research in this area would be the discovery or development of a new filler for pharmaceuticals without the contraindications possible with lactose.