Chemotherapy-Induced Neutropenia: Strategies for Pharmacists

Chemotherapy-induced neutropenia (CIN) is a common adverse occurrence in patients treated for solid tumors.

Pharmacists who often see CIN will find a review published ahead-of-print in Expert Opinion on Pharmacotherapy enlightening. This paper emphasized optimal implementation of outpatient treatment and the use of colony-stimulating factor as add-on treatment with antibiotics.

CIN compromises cancer treatment when chemotherapy doses need to be held or reduced. It also affects inflammatory response against pathogens, potentially leading to hospitalization, unnecessary morbidity and mortality, and higher health care cost.

Patients with CIN tend to be more susceptible to gram-positive infections, although about 30% of infections seen are gram-negative.

Clinicians can reduce the likelihood of infection in neutropenic patients by reducing chemotherapy doses, administering growth factors prophylactically, and prescribing antibiotics before the CIN occurs or escalates to febrile neutropenia (FN).

However, the authors noted that fluoroquinolone prophylaxis could contribute to increasing drug resistance.

Low-risk FN patients can be safely treated on an outpatient basis, so retail pharmacists are likely to see them. Still, controversy surrounds the best treatment approaches in this setting.

Some oncologists routinely use colony-stimulating factor in combination with antibiotics for CIN, but its effect on infection-related mortality has not been documented.

Since more than half of cancers occur in patients aged older than 65 years, it is critical for pharmacists to know that advanced age does not necessarily mean that dose reductions are needed. Many older patients respond to chemotherapy and supportive regimens similar to their younger counterparts.

Rather than using calendar age to plan treatment, clinicians should assess each patient’s functional status, examine renal and hepatic function, manage comorbidities, and adjust treatment doses only if warranted.

Alternative treatments include a low-bacterial diet, which is poorly defined, and acupuncture with moxibustion, which is a traditional Chinese medicine therapy using moxa made from dried mugwort. No evidence supports these interventions, however.