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Navigating Lactose Intolerance: The Role of Pharmacists and Nutrigenomics

Lactose intolerance is a common condition affecting millions of people worldwide. This condition can significantly impact a patient's life, including their choice of medications. In this article, we will discuss the impact of lactose intolerance on patients' lives and medications and how pharmacists can help manage this condition.

paper that says lactose free next to stethescope

Medications Containing Lactose

Lactose is often used as an inactive ingredient in various medications. Some examples of medications that contain lactose are:

  • Alprazolam

  • Cetirizine Hydrochloride

  • Lorazepam[1]

Patients with lactose intolerance should consult their healthcare provider or pharmacist for suitable alternatives if needed[2].

Symptoms of Lactose Intolerance

Symptoms of lactose intolerance typically occur within 30 minutes to 2 hours after consuming lactose-containing foods and may include:

  • Bloating

  • Gas

  • Diarrhea

  • Abdominal pain

  • Nausea

The Genetics Behind Lactose Intolerance

Lactose intolerance is primarily caused by a deficiency in lactase, an enzyme responsible for breaking down lactose. The production of lactase is regulated by the LCT gene, which is located on chromosome 2[3]. Genetic variants in the LCT gene and its regulatory region, such as single nucleotide polymorphisms (SNPs), can affect lactase production and result in lactose intolerance.

One of the most well-known SNPs associated with lactose intolerance is the C/T-13910 variant, located in the regulatory region of the LCT gene [4]. Individuals with the T/T genotype typically have normal lactase production and can digest lactose, while those with the C/C or C/T genotype have reduced lactase production, leading to lactose intolerance.

Lactose Free Options: almonds, oat and rice milk
Lactose Free Options

Applying Nutrigenomic Services to Help Patients with Lactose Intolerance

Pharmacists can apply nutrigenomic services to help patients with lactose intolerance by:

  1. Genetic Testing: Pharmacists can recommend genetic testing to identify SNPs and genetic variants associated with lactose intolerance, such as the C/T-13910 variant. This information can help patients understand their risk of developing lactose intolerance and guide personalized dietary recommendations[5].

  2. Personalized Dietary Recommendations: Based on the genetic testing results, pharmacists can provide personalized dietary recommendations for patients with lactose intolerance, such as suggesting lactose-free or low-lactose dairy products, lactase supplements, and non-dairy alternatives[6].

  3. Educating Patients: Pharmacists can educate patients about the genetics behind lactose intolerance and the importance of a personalized approach to managing the condition. This can empower patients to make informed decisions about their diet and medications.

  4. Collaborating with Healthcare Providers: Pharmacists can collaborate with healthcare providers, such as dietitians and primary care physicians, to develop comprehensive, personalized care plans for patients with lactose intolerance, incorporating nutrigenomic information and dietary modifications[7].

Lactose intolerance can have a significant impact on a patient's life and their choice of medications. Pharmacists play a crucial role in helping patients manage this condition by identifying medications containing lactose, suggesting suitable alternatives, and providing guidance on dietary modifications and lactase supplements. By understanding the genetics behind lactose intolerance and applying nutrigenomic services, pharmacists can contribute to personalized care and help patients manage their condition more effectively.


  1. Akan P, Deloukas P. DNA sequence and structural properties as predictors of human and mouse promoters. Gene. 2008 Feb 29;410(1):165-76. doi: 10.1016/j.gene.2007.12.011. Epub 2007 Dec 23. PMID: 18234453; PMCID: PMC2672154.

  2. Di Stefano, M., Mengoli, C., Bergonzi, M., Klersy, C., Pagani, E., Miceli, E., & Corazza, G. R. (2017). Lactose in drugs: the silent effect of an excipient. Alimentary Pharmacology & Therapeutics, 45(6), 808-815. ↩

  3. National Library of Medicine. Genetics Home Reference. LCT gene. MedlinePlus. Accessed [June 1, 2023].

  4. Akan P, Deloukas P. DNA sequence and structural properties as predictors of human and mouse promoters. Gene. 2008 Feb 29;410(1):165-76. doi: 10.1016/j.gene.2007.12.011. Epub 2007 Dec 23. PMID: 18234453; PMCID: PMC2672154.

  5. Pray, W. S. (2008). Understanding and managing lactose intolerance. US Pharmacist, 33(12), 12-15.

  6. Misselwitz B, Butter M, Verbeke K, Fox MR. Update on lactose malabsorption and intolerance: pathogenesis, diagnosis and clinical management. Gut. 2019 Nov;68(11):2080-2091. doi: 10.1136/gutjnl-2019-318404. Epub 2019 Aug 19. PMID: 31427404; PMCID: PMC6839734.

  7. Martin, M. A., & Solomons, N. W. (2018). Pharmacists' role in managing lactose intolerance. Journal of the American Pharmacists Association, 58(6), 607-608.


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