Ertürk NE, Taşci S. The effects of peppermint oil on nausea, vomiting and retching in cancer patients undergoing chemotherapy: an open label quasi-randomized controlled pilot study. Ther Med. January 2021;56:102587. doi: 10.1016/j.ctim.2020.102587.
Nausea, vomiting, and retching are common effects of chemotherapy and can lead to fluid-electrolyte imbalance, dehydration, weight loss, physiological changes, and decreased kidney function. Additionally, nausea and vomiting affect a patient's social and work lives, daily activities, and psychological well-being. The drugs used to manage nausea and vomiting can cause adverse effects such as heartburn, insomnia, headache, dizziness, constipation/diarrhea, and dry mouth. Aromatherapy is used by patients to cope with chemotherapy-induced nausea and vomiting; however, few studies have been conducted of its efficacy. These authors conducted an open-label, quasi-randomized controlled pilot study to evaluate the effects of aromatherapy using peppermint (Mentha × piperita, Lamiaceae) essential oil in patients undergoing chemotherapy.
The study was conducted in the ambulatory chemotherapy unit of a public hospital in Turkey and included a quantitative phase (using a quasi-randomized, controlled study exploring the effects of aromatherapy on nausea, vomiting, and retching) and a qualitative phase (using semistructured questionnaires and individual in-depth interviews with the patients before they had chemotherapy and at the end of follow-up).
Inclusion criteria of the study were the following: age of at least 18 years; able to understand and communicate in Turkish; cancer diagnosis; presence of nausea; two remaining chemotherapy treatments using similar chemotherapeutic agents; no pregnancy; cancer at stage 3 at most; and no psychiatric disorders.
From September 2017 to September 2018, the authors screened 250 cancer patients undergoing chemotherapy. Of those patients, 140 met the inclusion criteria, and 90 patients agreed to participate in the study.
Forty-five patients were assigned to the intervention group, and 45 patients were assigned to the control group. In the intervention group, four patients decided not to participate after the start of the study, three discontinued the study because of increased severity of nausea, and two dropped out due to mild headache. In the control group, one patient decided to quit the study. The final analysis included 36 patients in the intervention group and 44 patients in the control group. The patients were aged 49.94 ± 10.47 years in the intervention group and 54.63 ± 10.15 years in the control group. Baseline characteristics were similar in both groups.
Data were collected at baseline and on each of the five days following chemotherapy by using a patient information form, a visual analog scale for nausea severity, a patient watch chart, the Index of Nausea, Vomiting, and Retching (INVR), and a patient opinion form on aromatherapy practice. Before chemotherapy, all patients were prescribed, intravenously, a corticosteroid (16 mg dexamethasone) and anti-nausea drugs (3 mg granisetron and 10 mg metoclopramide). After chemotherapy, the patients were prescribed antiemetic prophylaxis (8 mg ondasetron and 10 mg metoclopramide) to use at home.
The control group did not receive any study treatment. The patients in the intervention group applied one drop of the aromatic oil mixture between their upper lip and nose three times daily (morning, afternoon, and evening) for five days following chemotherapy. They were instructed to breathe deeply after applying the mixture. The mixture was prepared of 3% peppermint essential oil and sweet almond (Prunus amygdalus, Rosaceae) oil as the carrier. The aromatic oil mixture was prepared with essential oil by Nu-Ka Defne Esencia Company in Alanya, Turkey.
In the intervention group, the VAS nausea score decreased significantly compared with baseline in patients receiving the following chemotherapy: folfirinox (P < 0.001), paclitaxel-trastuzumab (P = 0.014), carboplatin-paclitaxel (P < 0.001), and cyclophosphamide-adriamycin (P = 0.005). No significant changes were seen in the patients receiving cisplatin or in patients in the control group. Nausea severity scores were significantly lower in the intervention group compared with the control group at each time point in patients receiving folfirinox, paclitaxel-trastuzumab, carboplatin-paclitaxel (except on the evening after chemotherapy), and cyclophosphamide-adriamycin (except on the evening after chemotherapy and on the first day after treatment).
The INVR daily scores of the patients who received folfirinox, paclitaxel-trastuzumab, carboplatin-paclitaxel, and cyclophosphamide-adriamycin were lower in the intervention group compared with the control group (except in patients receiving paclitaxel-trastuzumab on the first day); the between-group differences were significant (P < 0.05).
In this study, aromatherapy using peppermint essential oil significantly reduced the frequency of nausea, vomiting, and retching, and the severity of nausea in cancer patients undergoing chemotherapy.
This study was financially supported by the Unit of Scientific Research Projects of Erciyes University in Kayseri, Turkey. The authors declare no conflicts of interest.