The Effect of Peppermint Oil on Nausea, Vomiting and Retching in Cancer Patients Undergoing Chemotherapy

The aim of this study was to determine the effect of peppermint oil upon incidence of nausea, vomiting and retching, nause severity, and the usage amount of antiemetics in cancer patients undergoing chemotherapy.

Nausea, vomiting and retching symptoms are among the most common adverse effects of chemotherapy and are defined with expressions like "the biggest problem including pain" by patients. Chemotherapy-induced nausea and vomiting (CINV)' is reported leads to fluid-electrolyte imbalance, dehydration, loss of weight, physiological effects caused by poor drug absorption or decreased elimination from kidneys as well as negative effects in one's social life, work-life, activities of daily life and psychological status. Also, nausea-vomiting may cause some patients to refuse chemotherapy or to discontinue the treatment. Inadequate control of CINV leads patients to integrative health practices.

The study was realized as a randomized controlled study in order to explore the effect of use of 3% peppermint oil applied on lips three times a day during the five days following chemotherapy upon incidence nausea, vomiting, and retching, nausea severity and quantity use of antiemetics in cancer patients undergoing chemotherapy.The study was initiated on the 10.09.2017 and in this study were interviewed with 250 patients. 90 patients that met inclusion criteria were contacted. The study was completed with 36 intervention patients and with 44 control patients (See Fig. 1). For determine to sample size, while patients were being allocated to the study groups, post hoc power analysis was periodically done with the data obtained. The sample size for this study was calculated using the MedCalc (32-bit). The process continued until the necessary sample size was reached. According to power analysis, α = 0.05 and β =0.20, and the power of the study was 99.9%.

Randomization In order to provide randomization was preferred ballot method. As a result of the ballot, the first patient who inclusion criteria of study was allocated to the intervention group while the next one to the control group. After participant enrollment, patients were assigned to the two groups in a 1:1 ratio according to this rule. Because of it is not known whether nausea/vomiting experience of patients who first time chemotherapy receiving, study groups included patients receiving two or more chemotherapy.

Interventions 2.4.1. The control group The control group underwent only the routine treatment. The patients in the control group, Patient Watch Chart, Patient Nausea Severity Follow-up Form, and INVR, marked by patients and They were returned the duly completed these forms to the researcher when they came to hospital for the next chemotherapy treatment. Patient Watch Chart, and INVR skala of patients who illiterate were filled in by the pollster, according to expression of patient. In order to fill in Patient Watch Chart, and INVR phone interviews were made twice a day (morning-evening) by the pollster and the participants at a suitable time determined together.

2.4.2. Intervention group The patients in the intervention group received routine medical treatment program and were asked to put one drop of peppermint oil upon lips following chemotherapy administration. Before peppermint oil application; the researcher theoretically and practically provided a training of 8-10 minutes about the use of peppermint oil and the patients were requested to apply this oil three times a day according to "Oil Practice Guide" (See Fig. 2) in the morning (09:00), at noon (15:00) and in the evening (21:00). The mobile phones of the participants were set to these hours and the alarm system continued in this manner for five days. The participants whose mobile phones were not set to these hours were called by the researcher in order to recall them of the protocol. Before peppermint oil application, Patient Opinion Form (pre-application) were asked to the participants and their answers were written down. Similarly; after peppermint oil application, same form (post-application) were asked and the answers were written down. Patient Watch Chart, Patient Nausea Severity Follow-up Form, and INVR, marked by patients and They were returned the duly completed these forms to the researcher when they came to hospital for the next chemotherapy treatment. Patient Watch Chart, and INVR skala of patients who illiterate were filled in by the pollster, according to expression of patient. In order to fill in Patient Watch Chart, and INVR phone interviews were made twice a day (morning-evening) by the pollster and the participants at a suitable time determined together.

Patients in the intervention and control groups were allowed to take standard antiemetic medications and other drugs taken for different medical problems during and after the day of peppermint oil application. As a part of standard antiemetic treatment; patients were given " in isotonic solution 5-HT3 receptor antagonists (palonosetron, granisetron (Kytril))+ steroids (dexamethazon (Decort)) + antihistaminic (Avil or Systral ampul) + Metpamid ampul" before chemotherapy.

Onzyd 8 mg (ondansetron) + metpamid tb. has been prescribed by oncologist, for able to use at patient's home.

Eligibility Criteria:
Inclusion Criteria: Patients who

* were aged ≥18 years,
* were able to understand Turkish language and to communicate in Turkish language,
* had cancer diagnosis,
* received chemotherapy treatment for -at least- the second time with similar chemotherapeutic agents,
* experienced nausea symptoms according to VAS
* were not pregnant and not intending pregnancy,
* had -at most- stage III cancer
* presented no psychiatric disorders,
* were not included in pre-implementation phase of the study were accepted to the study.

Exclusion Criteria:Patients who

* suffered from another disease that may affect nausea vomiting status,
* were allergic to or disturbed by smell of peppermint,
* were newly diagnosed, and receiving chemotherapy for the first time,
* received concomitant radiotherapy,
* received other complementary and integrative health practices during the treatment were not accepted to the study