The Role of the Specialty Pharmacist in Treating Colorectal Cancer

Pharmacists are sometimes an undervalued and underutilized part of the health care team; however, pharmacists are able to fill many of the gaps that exist in the health care system. Pharmacists are able to provide a variety of clinical services, including order verification, identifying drug interactions, completing medication reconciliations, dispensing, medication administration and storage, management of adverse effects (AEs), and patient counseling.

Although pharmacists are able to provide these services and more, clinical pharmacy specialists are also able to hone in on specific clinical skills, such as oncology, to provide the best care possible for patients. Here, we are examining the pharmacist’s role in the management of colorectal cancer.

Colorectal cancer is among the most prevalent types of cancer in the western world, affecting 1 in 23 males and 1 in 25 females throughout their lifetime. It is the third leading cause of cancer-related deaths among men and women, but this rate has been dropping over the past decade, likely due to improved screening and treatment options.¹

As most forms of colorectal cancer begin as a polyp, the gold standard for screening is a colonoscopy. In the United States, the current recommendation is that adults aged 50 to 75 years be screened for colorectal cancer every 10 years as long as results are negative.

Those at an increased risk of developing colorectal cancer (ie family history of colorectal cancer or polyps, history of inflammatory bowel disease, etc) are recommended to be screened prior to age 50 and have more frequent screenings. Colonoscopies are highly sensitive and effective, with studies suggesting a 60% to 70% decrease in deaths from colorectal cancer with routine screenings.²

Even with surveillance, colorectal cancer is still a prevalent disease state, but is a survivable cancer based on initial prognosis. There are many treatment options available that include surgery, chemotherapy, and/or radiation.

Chemotherapy may be involved in stage II colorectal cancer as an adjunct to surgery and is the mainstay of therapy in stages III and IV.^3,4 Chemotherapy is often complex and requires a more clinical role in prescribing, dispensing, and administering. Pharmacists are able to assist with providing patient education, verifying orders, mitigating AEs, assessing appropriateness of therapy, drug monitoring, and identifying drug interactions.

The mainstays of chemotherapy for colorectal cancer are fluorouracil (5-FU), capecitabine, and/or leucovorin. Common treatment regimens are FOLFOX (5-FU, leucovorin, and oxaliplatin), FOLFIRI (5-FU, leucovorin and irinotecan), and CAPEOX (capecitabine and oxaliplatin).^3,4 These regimens come with serious and sometimes limiting AEs, such as neuropathies associated with oxaliplatin and diarrhea with irinotecan in addition to typical AEs, including nausea, vomiting, diarrhea, fatigue, and alopecia.⁵

Those with stage IV may use monoclonal antibodies, such as bevacizumab (Avastin), cetuximab (Erbitux), or panitumumab (Vectibix). Pharmacists are key in this process.

Oncologists select agents based on a variety of factors, including prognosis and comorbidities, but pharmacists can assist with management of AEs, OTC recommendations, dosing, and drug/disease state interactions.

Each medication has AEs, but pharmacists are able to help reduce these by recommending a patient-specific therapy based on comorbidities, concurrent medication use, and other patient-specific factors. For example, if a patient was receiving FOLFIRI and was experiencing significant diarrhea, a pharmacist could recommend atropine or Imodium based on timing of the diarrhea.

Another example is a case of a pharmacist intervention in an outpatient cancer center clinic. A patient presented for her weekly infusion and was experiencing neuropathies associated with her oxaliplatin dose.

The physician recommended gabapentin; however, when reviewing the patient’s profile, it was noted she was taking duloxetine. Instead of initiating another medication, the pharmacist recommended increasing the dose of the patient’s duloxetine. This approach helped to decrease the patient’s symptoms while minimizing her pill burden.

A more serious AE of chemotherapy is immunosuppression, which puts patients at risk of developing serious and sometimes life-threatening infections. Many patients who develop an infection have to be admitted to the hospital and placed on empiric antibiotics.

Pharmacists work alongside the infectious disease team as well as oncologists to narrow therapy based on cultures. Pharmacists are able to de-escalate therapy and change intravenous administration to oral agents based on facility procedures and guidelines.

Pharmacists are also able to monitor therapeutic drug levels for antibiotics such as vancomycin. At many facilities, pharmacists are the ones ordering labs, following-up with the values, and adjusting doses under committee-reviewed policies.

In addition to AEs, many chemotherapeutic agents come with drug interactions. For example, capecitabine is an oral agent that is a weak inhibitor of CYP2C9 and has interactions with proton pump inhibitors, allopurinol, QT-prolonging agents, and vitamin K antagonists to name a few.⁵ Pharmacists are able to identify any potential interactions and intervene where appropriate.

A main area of focus for many hospitals and clinics now is medication reconciliation. Pharmacists conduct medication reconciliations by interviewing the patient, reviewing the patient’s dispense history, and contacting the patient’s health care providers, such as the primary care physician.

By compiling the patient’s list of medications and keeping it as up to date as possible, we are able to assess appropriateness of therapy, identify drug and disease state interactions, and make appropriate recommendations. This task can be tedious and is often overlooked, but it is a very important way to ensure patient safety.

Pharmacists are a rich resource, not only in the management of colorectal cancer, but in every aspect of health care. From providing patient counseling to performing therapeutic drug monitoring, pharmacists are a valuable tool for everyone, including physicians, nurses, physician assistants, and patients.

Pharmacists are among the most accessible health care professionals and are willing and able to be an advocate for patient safety and health outcomes.

References

• Key Statistics for Colorectal Cancer. American Cancer Society. https://www.cancer.org/cancer/colon-rectal-cancer/about/key-statistics.html. Accessed April 9, 2020.
• Tests to Detect Colorectal Cancer and Polyps. National Cancer Institute. https://www.cancer.gov/types/colorectal/screening-fact-sheet. Accessed April 9, 2020.
• National Comprehensive Cancer Network. Colon Cancer (Version 2.2020). https://www.nccn.org/professionals/physician_gls/pdf/colon.pdf. Accessed April 9, 2020.
• National Comprehensive Cancer Network. Rectal Cancer (Version 2.2020). https://www.nccn.org/professionals/physician_gls/pdf/rectal.pdf. Accessed April 9, 2020.
• Lexi-Drugs. Wolters Kluwer Health, Inc. Riverwoods, IL. Available at http://online.lexi.com. Accessed April 9, 2020.

About the Author

Emily Bintrim will graduate from the Duquesne University School of Pharmacy in May 2020.

Jonathan Ogurchak, PharmD, CSP, is the founder and CEO of STACK, a pharmacy information ecosystem, and serves as preceptor for a virtual Advanced Pharmacy Practice Experiential rotation for specialty pharmacy, during which this article was composed.