Antiemetic placebo: Reduce adverse drug interactions between chemotherapeutic agents and antiemetic drugs in cancer patients

Cancer Treatment Side Effects: A Meta-analysis of the Relationship Between Response Expectancies and Experience

CONTEXT

Although previous research has, overall, suggested a moderate relationship between response expectancies (REs) and cancer treatment-related side effects, empirical results have been mixed.

OBJECTIVES

We aimed to further explore these relationships, hypothesizing that REs would predict subsequent toxicities with the inclusion of more recent studies, across a broader range of side effects, while incorporating the impact of potential moderators including patients' experience with treatment and measurement methods. We further investigated the impact of REs across individual toxicities.

METHODS

A systematic search and analysis were conducted across four databases (PsychInfo, PubMed, CINAHL, and Embase) and reference lists, from 1985 to February 2016. This provided 27 eligible studies with 4474 participants, through which the main analysis, moderator analyses, and individual side-effect analyses were explored.

RESULTS

REs were moderately related to side effects overall (r = 0.26), and effect sizes were significantly influenced by sample diagnostic homogeneity, whereas differences between type and timing of measurement showed trends. Of the 16 toxicities examined, 15 demonstrated significant relationships between REs and side-effect experience, with hair loss (r = 0.48) the strongest. No clear difference emerged between objective and subjective side effects; however, significant differences across individual toxicities were revealed.

CONCLUSION

Findings support a relationship between REs and a wide range of subsequent side effects, yet differences between individual RE-toxicity associations emerged. These findings provide direction for the measurement of side effects and REs and support REs as potential targets for intervention during the informed consent process.

Characteristics of women with nausea and vomiting of pregnancy who chose to continue compassionate use of placebo after a randomised trial

The placebo effect has not been characterised in pregnant women suffering from nausea and vomiting of pregnancy (NVP). Our aim was to characterise determinants of the placebo effect in women treated with placebo for NVP. We analysed data from a multicentre, double blind randomised controlled trial of Diclectin (delayed release doxylamine and pyridoxine) vs placebo for the treatment of NVP. A total of 127 women in the placebo arm and 130 in the active arm provided evaluable data for this analysis. Women who chose to continue placebo on a compassionate basis (n = 41) had significantly better improvement in symptoms of NVP and higher Wellbeing scores than those who did not ask to continue compassionate use. Results were similar in the active drug arm. The request to continue compassionate use of either placebo or active drug could be predicted by greater improvement in symptoms of NVP during the trial period.

Reduction of motion sickness with an enhanced placebo instruction: an experimental study with healthy participants

OBJECTIVE

Expectancy and conditioning are underlying mechanisms of placebo and nocebo responses. In previous studies with motion sickness, we could induce nocebo responses by both methods, but no placebo responses.

METHODS

In Experiment 1, 64 volunteers (50% women, mean age = 23.5 years) were evaluated to determine the degree they realized speed changes in nauseogenic rotation. For Experiment 2, 32 volunteers (50% women, mean age = 26.0 years) were exposed to fast rotation (15 rounds per minute, or rpm) on Day 1. On Day 2, they either received a drink with a presumed effective antiemetic (actually placebo) or were told they belonged to the control group. Rotation was surreptitiously reduced (to 10 rpm). On Day 3, they were tested with the initial rotation speed. Outcome variables in both experiments were symptom ratings; additionally in Experiment 2, the number of nauseogenic head movements, tolerated rotation time, and electrogastrogram were analyzed for changes between Days 1 and 2 (expectancy plus speed reduction) and Days 1 and 3 (expectancy plus conditioning).

RESULTS

In Experiment 1, a dose-response function was established for different rotation speeds, with the smallest perceived difference between 10 and 15 rpm. In Experiment 2, placebo application induced better maximal symptom rating, head movement, and rotation time at Day 2 (F = 3.097, p = .043) and Day 3 (F = 3.401, p = .031). Electrogastrogram was unaffected.

CONCLUSIONS

Verbal suggestions combined with a conditioning procedure are effective in reducing symptoms of motion sickness.

Effects of ginger and expectations on symptoms of nausea in a balanced placebo design

OBJECTIVE

Ginger effects on (experimental) nausea have been described, but also strong placebo effects and sex differences when nausea is involved. The "balanced placebo design" has been proposed to allow better separation of drug and placebo effects.

METHODS

Sixty-four healthy participants (32 women) were randomly assigned to receive an antiemetic ginger preparation or placebo, and half of each group was told to have received drug or placebo. They were exposed to 5×2 min body rotations to induce nausea. Subjective symptoms and behavioral (rotation tolerance, head movements) and physiological measures (electrogastrogram, cortisol) were recorded. Groups were balanced for sex of participants and experimenters.

RESULTS

Ginger and the information given did not affect any outcome measure, and previous sex differences could not be confirmed. Adding the experimenters revealed a significant four-factorial interaction on behavioral but not on subjective or physiological measures Men who received placebo responded to placebo information when provided by the male experimenter, and to ginger information when provided by the female experimenter. This effect was not significant in women.

CONCLUSION

The effects of an antiemetic drug and provided information interact with psychosocial variables of participants and experimenters in reports of nausea.

Impact of depression mood disorder on the adverse drug reaction incidence rate of anticancer drugs in cancer patients

The aim of this study was to explore the impact of depression mood disorder on the incidence of adverse drug reactions of anticancer drugs in cancer patients. The Hamilton Depression Scale 17 was used to evaluate the depression mood disorder level in 73 cancer patients before chemotherapy. Pharmacists monitored adverse drug reactions during the chemotherapy period. The relationship between depression mood disorder level and the incidence of adverse drug reactions was analysed. The frequency and extent of total adverse drug reactions were not related to depression mood disorder level. The frequency and extent of subjectively experienced adverse drug reactions such as anorexia, nausea and fatigue were related to depression mood disorder level. In conclusion, psychological support and intervention should be provided to cancer patients in order to improve patient adherence and cancer chemotherapy effectiveness, and to decrease the incidence of adverse drug reactions.