Managing the Side Effects of Chemotherapy

Side effects are unfortunately highly likely to be experienced by almost all patients receiving chemotherapy. Managing side effects effectively ultimately means optimisation of chemotherapy. Side effect management is influenced by a number of aspects such as:

• Other medical conditions the patient may have
• Concomitant medications being taken, including those as part of the treatment protocol, e.g. anti-emetics, etc.
• Whether the chemotherapy regimen is curative or palliative
• How many cycles, or if any other treatment modalities, e.g. radiotherapy, are intended
• The specific chemotherapy drug(s) prescribed and the dose(s)
• Whether the patient is receiving treatment as part of a clinical trial, which may require specific management of side effects

The following six side-effects are most commonly experienced by patients:

Chemotherapy-induced nausea and vomiting

Chemotherapy-induced nausea and vomiting (CINV) is a common adverse effect of cancer treatment. Patients often report that this is a side effect that causes the greatest anxiety prior to commencing treatment, and it can negatively impact upon a patient’s quality of life. However, this adverse effect can be mostly circumvented by the application of international evidence-based guidelines and effective prophylaxis. Furthermore, the literature describes patient risk factors that can highlight those patients with a greater likelihood of experiencing CINV, such as youth, female gender, predisposition to motion sickness, morning sickness, low alcohol intake, and highly emetogenic chemotherapy protocols.

It has been identified by Vidal et al. (2011) that it is more probable that CINV will occur after the patient has left the outpatient clinic (where chemotherapy is most often administered). Accordingly, this can lead to the underreporting of CINV by the patient for several reasons. Such factors include: patients forgetting about such episodes or how their daily activities had been affected, not informing their doctor of CINV occurrences, or belittling the degree of CINV experienced for several reasons (e.g. fear that the onset of CINV may prompt a dosage decrease, postponement or cessation of treatment; or patients may consider that the incidence of CINV implies that the treatment is effective and therefore tolerate it).

A lack of CINV management can lead to increasing financial costs. Such costs include those incurred for hospital admission for intravenous rehydration, and costs that patients bear personally due to decreased function and productivity. The European CINV Forum recommends the following guidelines are followed:

• An emetogenicity calculation tool should be used to assess a patient’s risk of CINV;
• The emetogenicity of new chemotherapy drugs and protocols is in turn ascertained;
• Timely revision of local CINV protocols and guidelines as evidence-based international guidelines are updated;
• A “chemotherapy toxicity toolkit” including a patient diary, access to telephone support, and timely updates as new chemotherapy guidelines and protocols are made available, is devised to enhance the supportive care provided to address a spectrum of adverse effects;
• Provision of user-friendly patient information regarding CINV and its management;
• Undertake audits of CINV management at a local level.

Pharmacists can play an active role in the management of CINV by providing patient counselling, recording patient histories (including comorbidities and medication), and collaborating with oncologists in order to adapt anti-emetic medication regimes for individual patients. Collaborative efforts in the particular area of nausea and vomiting have led to measurement tools and anti-emetic guidelines that decrease the severity of nausea and vomiting on patient quality of life.

The mainstay of controlling CINV is typically prevention. Most chemotherapy protocols will be prescribed with prophylactic anti-emetic medicines, but unfortunately, various patients will still encounter CINV. Prior to suggesting any treatment, it is essential to assess the severity of the CINV since dehydration is a serious consequence. If this is the case, then the patient should be referred to the nearest hospital if the condition is critical. Anti-emetic medications that are prescribed typically include 5HT₃ antagonists, corticosteroids, dopamine antagonists, and antipsychotic agents. It is also important to consider the route of any anti-emetic, as some patients may not be able to accept oral administration. Various self-care tips can often benefit those experiencing CINV including:

• Eat dry food (e.g. toast or crackers)
• Eat small amounts when feeling able
• If cooking aromas trigger nausea, eat cold foods or foods that only require heating up
• Avoid fried and/or fatty foods
• Crystallised ginger, ginger tea or ginger biscuits can help with nausea
• Slowly sip soft drinks such as mineral water, lemonade, soda water, or ginger beer/ale

Fatigue

Fatigue is the most prevalent cancer symptom and is reported as the symptom that impacts quality of life to the greatest degree. The physiological disease or the treatments imposed can each cause fatigue, leading to loss of functionality, worsening symptoms and cognitive impairment. Anaemia can cause fatigue and is treatable, but in many cases, fatigue will arise in patients with a normal haemoglobin level. Mild exercise is considered to be of some benefit, but sufficient rest and support with household duties and childcare are often required. Assuring the patient that they can recover from fatigue after their treatment is essential.

Diarrhoea

Another common side effect is diarrhoea, which can be worse with certain drugs, including irinotecan, capecitabine and erlotinib. It is crucial to assess severity since, as for CINV, dehydration can develop rapidly and necessitates pre-emptive rehydration, often with intravenous fluids. Doctor referral is required for any patient experiencing more than four to six episodes of diarrhoea a day. Patients experiencing diarrhoea should be counselled to drink at least two litres of fluid per day. If the patient has a fever, then an infectious source for the diarrhoea should be assessed. Medications to treat diarrhoea include loperamide and codeine.

Mucositis

Mucositis is a common adverse effect involving complicated pathophysiology and treatment modalities. The pharmacist can play a role in devising protocols as well as effective patient management and the recommendation of methods of managing symptoms. It can be a troublesome complication leading to limitation of oral consumption and severe pain for the patient. There are several products available, including anti-inflammatory and antiseptic mouthwashes and oral gels, which are explicitly formulated for oncology patients. Treatment goals are normally to reduce pain and to continue oral consumption. Mucositis will generally resolve soon after chemotherapy. Infections of the oral cavity are often experienced, and oral thrush can be treated either systemically or topically subject to the degree of infection. Systemic analgesics can be used for oral pain, and sucking ice chips can relieve pain as well. It is recommended that good oral hygiene is continued, such as brushing teeth lightly using a soft toothbrush. Unless patients have thrombocytopaenia, then flossing is recommended, and lips are kept moisturised with lip balm. Patients should avoid foods that are salty, acidic or spicy.

Skin reactions

Chemotherapy can evoke dermatological reactions of varying severity, from minor to dose-restrictive. Depending on severity, the treatment required can range from using basic moisturisers or other topical preparations, but may require a doctor’s input to assess the need for antibiotics, steroids, or other agents. Self-care measures that can be recommended are as follow:

• Use sunscreen (SPF30+ or above)
• Use a moisturiser for dry skin and to protect nails (any radiotherapy patients should check with their doctor prior to using any topical products)
• Avoid wet shaving
• Use moisturiser
• Use gloves, as treatment may cause brittle nails
• Avoid false nails.

Myelosuppression

A particularly dangerous side-effect of chemotherapy is myelosuppression. This can in turn cause anaemia, and an increased risk of infection and bleeding. A chemotherapy patient who has a temperature over 38°C should be directed to immediately seek medical attention as they urgently require antibiotics. Many chemotherapy protocols indicate prophylactic antibiotics or GCSF (granulocyte colony-stimulating factor). Self-care tips in relation to decreasing the risk of developing an infection comprise:

• Avoid crowded places and people who may be unwell
• Make sure that food is cooked properly
• Avoid high-risk foods, such as raw animal products
• Wash hands well, particularly when undertaking food preparation and after visiting the toilet
• Seek medical assistance immediately if any anaemia symptoms, fever or bleeding arise

Further cancer information and resources are available from the PeterMacCallum Cancer Centre Victoria Australia website at https://www.petermac.org/services/cancer-information-resources.