Lactose is a disaccharide, or milk sugar, found naturally in dairy products. It is composed of glucose and galactose, which must be broken down by the enzyme lactase for proper absorption in the small intestine. Lactose intolerance occurs when the body produces insufficient lactase, reducing the ability to digest lactose. When undigested lactose reaches the large intestine, bacteria ferment it, causing gastrointestinal symptoms like bloating, gas, and diarrhea. The term “lactose medications” refers both to digestive aids and to many other medications that contain lactose as an inactive filler.
Understanding Lactase Enzyme Supplements
Lactase enzyme supplements are over-the-counter products designed to help manage the symptoms of lactose intolerance. These supplements work by providing the missing lactase enzyme externally, fulfilling the role the body cannot. The lactase splits the lactose into the easily absorbed sugars, glucose and galactose, preventing it from traveling undigested to the colon.
These digestive aids are available in various forms, including chewable tablets, capsules, and liquid drops, and are sourced from fungi or yeasts. They are not a cure for the underlying condition but a treatment to mitigate symptoms when consuming dairy. For optimal efficacy, the supplement should be taken immediately before or with the first bite or sip of a food or drink containing lactose. The typical dose ranges from 3,000 to 9,000 international units (IU), depending on the severity of the intolerance and the amount of lactose being consumed.
Lactose’s Role as a Pharmaceutical Excipient
Lactose is one of the most commonly used substances in the manufacturing of pharmaceutical drugs, found in an estimated 60% to 70% of oral medications. In this context, lactose is not the active medicine but an inactive ingredient known as a pharmaceutical excipient. Excipients are substances that stabilize the active drug, give the dosage form bulk, and aid in manufacturing.
Lactose is valued by drug manufacturers for its chemical stability, low cost, and lack of odor or strong taste. Its primary functions include acting as a diluent or filler, providing necessary bulk to a tablet or capsule, especially when the active drug ingredient is present in tiny amounts. It also functions as a binder, helping ingredients stick together, and a flow agent, ensuring the powder mixture moves smoothly through manufacturing equipment.
Pharmaceutical-grade lactose, typically derived from skimmed milk, is purified and processed into different forms to suit various drug formulations. Different crystalline forms of lactose are used to optimize properties like compressibility and flowability needed for mass-producing tablets. Lactose remains a standard excipient in both generic and brand-name tablets, capsules, and some dry-powder inhalers.
Identifying and Managing Lactose in Medications
For most people with lactose intolerance, the small amount of lactose present in a pill is unlikely to cause significant gastrointestinal symptoms. The amount of lactose in a single tablet or capsule is usually less than 1 gram, and total daily exposure from medications is generally under 2 grams. This is significantly lower than the typical threshold for symptoms, which is around 12 grams of lactose, equivalent to roughly one cup of milk.
However, individual tolerance levels vary widely, and some sensitive people may experience symptoms from doses as low as 100 to 200 milligrams. Patients taking multiple medications that all contain lactose should consider the cumulative effect of these small doses. The first step for anyone concerned is to check the product labeling, though a drug’s Summary of Product Characteristics, often available through a pharmacist, provides the definitive list of excipients.
If a severe intolerance or a history of reactions necessitates avoiding even trace amounts, consultation with a pharmacist or prescribing physician is warranted. They can help identify lactose-free formulations, including specific brands, liquid medications, or compounded drugs prepared by a specialty pharmacy. Patients with mild sensitivity can simply take their lactase enzyme supplement immediately before consuming the lactose-containing medication to help digest the excipient.