Quantifying the 'hidden' lactose in drugs used for the treatment of gastrointestinal conditions.

BACKGROUND

Lactose intolerance affects 70% of the world population and may result in abdominal and systemic symptoms. Treatment focuses predominantly on the dietary restriction of food products containing lactose. Lactose is the most common form of excipient used in drug formulations and may be overlooked when advising these patients.

AIM: To identify and quantify the amount of lactose in medications used for the treatment of gastrointestinal disorders and to identify 'lactose-free' preparations.

METHODS

Medications used for the treatment of gastrointestinal disorders were identified from the British National Formulary (BNF). Their formulation including excipients was obtained from the Medicines Compendium. The lactose content and quantity in selected medications was measured using high-performance liquid chromatography (HPLC).

RESULTS

A wide range of medications prescribed for the treatment of gastrointestinal conditions contain lactose. We have quantified the lactose content in a selection of medications using HPLC. Lactose is present in amounts that may contribute towards symptoms. Lactose-free alternatives were also identified.

CONCLUSIONS

Lactose is present in a range of medications and may contribute towards symptoms. This may not be recognized by the prescribing doctor as excipients are not listed in the BNF, and the quantity of lactose is not listed on the label or in the accompanying manufacturer's leaflet.