Olanzapine for Intractable Nausea and Vomiting in Palliative Care Patients Not Receiving Chemotherapy

Dear Editor:

Intractable nausea and vomiting are uncommon symptoms in palliative care patients but can cause debilitating reductions in quality of life. ¹ The cause is often multifactorial and treatment frequently requires multiple medication combinations, which may lead to significant drug-drug interactions and adverse effects.^2,3

Olanzapine is an atypical anti-psychotic, has a broad spectrum of activity against multiple neurotransmitter receptors involved with nausea pathways, and is used successfully in patients on chemotherapy. ⁴ This study reports on four palliative patients successfully treated with olanzapine who had previously been resistant to multiple antiemetics and who were not receiving chemotherapy.

The investigation was a one-year, retrospective, single-center design. Patients were included in the study if they (1) had nausea and vomiting not responding to three or more antiemetics, (2) had nausea and vomiting not due to an obvious reversible condition, and (3) were not already taking olanzapine.

Two males and two females with an average age of 65 years (SD=12) were identified (see Table 1). The type of cancer varied between the patients. Two patients had metastatic disease. The average time since chemotherapy was 67 days (SD=26). All patients were Caucasian. The initial daily dose was 5 mg in each patient given regularly at night.

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Table 1.

Demographics and Antiemetic Use and Cost Savings Pre- and Post-Olanzapine Administration

Patient	Age	Sex	Diagnosis	Metastasis	Different antiemetic use pre- olanzapine	Different antiemetic use post- olanzapine	Cost saving per 24 hours in $ AUD and percent reduction (%)
1	71	F	Cervical carcinoma with localized spread	Nil	4	1	17.53 (93.29%)
2	72	M	Head of pancreas	Liver	5	2	25.49 (80.13%)
3	83	F	Bladder transitional cell carcinoma with localized spread	Nil	3	2	10.99 (70.31%)
4	47	M	Rectal adenocarcinoma	Liver	5	2	17.19 (67.04%)

Overall olanzapine reduced the need for any other regular antiemetic medication and reduced ‘as needed’ rescue antiemetics (4 versus 1, CI 1.16–4.84, 95%; 3 versus 1, CI 0.58–2.42, 95%). All patients remained on olanzapine until they became unable to take oral medication and reached end-of-life care. The average length of therapy was 26 days (SD=20).

There were no episodes of extrapyramidal side effects. One patient reported mild somnolence in the first week of treatment which required a reduced dose of olanzapine to 2.5 mg daily. No further adjustments were required.

In addition to the above results, the use of olanzapine was examined for its cost effectiveness. Olanzapine was associated with significantly decreased cost of antiemetic medication per 24 hours when the average cost was calculated pre- and posttreatment ($22.97 versus $5.17, CI 8.34–27.26, 95%).

This research supports previous small studies^3,5 and adds cost effectiveness and reduction in polypharmacy, which had not been previously studied.

There are obvious limitations to this research, with low patient numbers and the retrospective design. However, larger studies are warranted as olanzapine appears to be an effective, well tolerated, and cost effective treatment for medication resistant nausea and vomiting. Additionally, olanzapine also reduces polypharmacy and limits possible drug-drug interactions.