Page 36 Complete Your CE Test Online - Click Here and smoking are important too, as these can sometimes affect drug metabolism. Continuing to smoke can slow healing and increase certain toxicities of cancer treatment. If the patient smokes, this is a good time to assess the person’s readiness to quit. Nursing consideration: To improve success and reduce side effects of cancer treatment, encourage patients to quit smoking before cancer treatment begins. Smoking cessations works best when the patient has emotional support with the mental part and pharmaceutical assistance to reduce withdrawal symptoms. It is essential that the professional nurse take such histories in a private location and in a non-judgmental fashion, especially when moving into a discussion of amounts of alcohol used each week, and use of illegal or non-prescribed drugs. This full drug/substance listing can be used, along with the treatment plan, in a drug interaction evaluation. Pregnancy and childbearing plans: It is important to ask about possible pregnancy and pregnancy risk in premenopausal women, since cancer treatment can cause birth defects, fetal wasting, and other harmful effects in the embryo. Men and premenopausal women should also be asked about any plans or thoughts about having children in the future. Patients will need to know that cancer treatment can sometimes cause infertility, and options become much more limited after treatment is started. Knowledge For informed consent purposes, this is a good time to check the patient’s understanding of their diagnosis, prognosis, and plan of care, and to correct any misconceptions. By this time there will be a treatment plan of some sort, though it may be subject to changes. Most patients have had a chance to come up with concerns and questions (see also “Informed consent” and “Resources for Patients”). Teaching: Tell the patient that they should let the nurse and the doctor know about any changes they make in the drugs or supplements they are taking. This necessitates the updating of the drug list and repetition of the drug interaction evaluation as well as any time before medication regimens are changed or when side effect management medications are to be added. It is helpful to explain to the patient that there are many drugs, including over-the-counter medicines and supplements that interact with each other in the body in very predictable ways. Some drugs interact with grapefruit and starfruit or with herbs like St. John’s wort. Some of these interactions can be enough to cause problems with cancer drug treatments, such as sub-therapeutic drug levels or unexpected toxicities due to the high levels of drug in the body. It is a good time to ask the patient about supplements and herbs, and let them know that grapefruit can cause problems with a lot of medicines. There are other kinds of interactions, such as physical ones that patients may need to understand, e.g. that a calcium supplement or calcium based antacid cannot be taken within a certain number of hours of a drug dose because the calcium in the stomach prevents the drug’s absorption. The action of some drugs causes problems with other drugs; for instance, some drugs requiring an acidic environment in the stomach, such as erlotinib, will not dissolve or absorb well when a person is taking stomach acid inhibitors, like proton pump inhibitors, which raise the pH of the stomach for many hours [241]. Interactions with foods are generally much better known, since food in the stomach can help some drugs absorb, but keep others from being absorbed. Most dietary supplements do not appear to cause harm during cancer treatment. For some time, herbal supplements were posited to be harmful when taken during chemotherapy or radiation therapy because high antioxidant levels might interfere with the mechanisms of chemotherapy and radiation. After a lot of debate on the matter, it was generally concluded that while more research is needed, there is little evidence of harm except to smokers receiving radiation therapy, who had shorter survival in a clinical trial where they took high doses of beta carotene supplements than smokers who did not take them [51]. In one study, high doses of supplemental vitamin E (taken alone), were linked to a slightly higher rate of prostate cancer in men who had lower levels of selenium in the body [186]. Finally, St. John’s wort can accelerate excretion of a number of drugs due to its induction of 2C9, 2C19, and 3A4 in the CYP-450 enzyme system [92]. This can make a number of drugs less effective (see “drug interactions”). Different practices and facilities may have different ways to advise patients about these possibilities. Antidepressants and other drugs that affect serotonin levels can precipitate serotonin syndrome, especially when taken with other drugs which also affect serotonin levels, such as opioids, ondansetron, metoclopramide, and certain anticonvulsant drugs that may be used for adjuvant pain management. Sometimes these combinations can be avoided, but patients need to know what to watch for, such as mental status changes, neuromuscular changes (e.g. muscle rigidity, clonus, restlessness, shivering, tremor), and autonomic hyperactivity (e.g. sweating, diarrhea, flushing, tachycardia) so that preventive interventions can be taken quickly [53]. Many people who take these medicines every day (and often, even the doctors who prescribe them) are unaware of this potential problem. Finally, of course, drugs can interact by potentiating each other or magnifying the same effects, e.g. the CNS depressant effects of opioids and benzodiazepines, which can also potentiate those of other drugs or alcohol. Drug side effects During this period, it is also a good time to review common side effects with the patient and get an idea of how well informed they are regarding the risks and benefits of their proposed treatment. In some settings, patients may need to sign a consent form before they start cancer treatment, so the nurse will need to document teachings in the record. This is also a good time for information handouts and sharing reliable resources they can call or visit online with questions, such as the American Cancer Society and the National Cancer Institute (see “Patient resources”). It is also a good idea to caution patients that there are a lot of unreliable information sources on the Internet, and many scammers, and useless “treatments.” Patients can learn more about these issues at the FDA’s website, Informed consent for cancer treatment True informed consent is an exchange of information between the patient and provider, and can be revoked at any time. The patient, proxy, or guardian needs to know the diagnosis, proposed treatment, purpose of treatment, expected risks and benefits of the proposed treatment, possible alternatives to the proposed treatment and these likely outcomes (including no treatment), how long treatment is expected to last, and how treatment will affect their normal activities; all this before consenting to treatment. The patient should also be given the chance to ask questions, confer with family or others if needed, and be clearly informed that s/he can take back consent at any time even if a form is already signed. The patient should also understand that s/he will be kept up to date as things change or new information comes to light (for instance, if their labs require changes or delays in treatment, or if new clinical trial information becomes available about the drugs that are being used) [30]. Some practices use a consent form for cancer treatment and others do not, but a consent form cannot replace the process of informed consent. Informed consent starts well before the initiation of treatment, and is continued all the way through treatment completion. Whether or not a form is used, informed consent is an ongoing process over time [264]. For more detail, a modifiable informed consent discussion guide for cancer treatment can be downloaded at no cost from the American Society of Clinical Oncology (ASCO) website. The discussion guide has reminders of the main points that need to be covered and