Persistent hiccups with continuous intrathecal morphine infusion. Clin J Pain. 2012;28:172-174. [PMID: 21677564 DOI: 10.1097/ajp.0b013e31822364a8]

Recurrent Persistent Hiccups on Opioid Treatment: A Case Report and Literature Review

Hiccups are a rare but potentially debilitating side effect of opioid treatment, with only a handful of reported cases in the medical literature. The pathophysiological mechanism linking opioids and hiccups is unknown, and a lack of evidence exists concerning the optimal management of the condition. We report on a 64-year-old man diagnosed with advanced renal cancer and painful osteolytic metastases, presenting persistent hiccups while on opioid treatment. Hiccups recurred after multiple challenges with codeine, morphine and hydromorphone on separate occasions. Hiccups ceased only after opioid discontinuation, although various pharmacological treatments were tried to shorten the duration of hiccups. Eventually, fentanyl was introduced and was well tolerated by the patient, without any recurrence of hiccups. The chronological correlation between opioid initiation and the onset of hiccups, as well as opioid discontinuation and the termination of hiccups leads to the conclusion that a causal role of codeine, morphine and hydromorphone in this occurrence is likely. Individual susceptibility probably plays a central role in the development of opioid-related hiccups. Opioid rotation is a promising strategy in the management of opioid-related hiccups, particularly when the mere discontinuation of the opioid is not a viable option, such as in the oncology and palliative care field.

Tramadol-induced hiccups: a case-noncase study in the European pharmacovigilance database

Background

Hiccups are usually benign and self-limiting, but can sometimes be persistent. If left untreated, they can provoke severe discomfort, and even death. Hiccups can be idiopathic, organic, psychogenic, and caused by drugs. Although some case reports have suggested a possible association between tramadol and hiccups, to our knowledge, no study has analyzed this possible relationship. The aim of this study was to analyze whether a disproportionate number of cases of hiccups are reported for tramadol in the EudraVigilance database.

Methods

A case-noncase study was conducted to assess the association between hiccups and tramadol, calculating reporting odds ratios (RORs) from 1 January 1995 to 11 September 2020. Cases were selected using the preferred term 'Hiccups'. The noncases used as controls were all other adverse drug reaction reports recorded in EudraVigilance during the same period. Exposure was defined as exposure to tramadol among cases and noncases. To reduce the risk of confounding by indication, the RORs for tramadol compared with other opioids were obtained. Additionally, we performed a confirmatory analysis in the World Health Organization pharmacovigilance database, VigiBase^®.

Results

There were 3089 cases of hiccups in the 7,213,623 reports. Tramadol was involved in 50 cases. The ROR for tramadol exposure was 3.35 [95% confidence interval (CI) 2.53-4.43]. This association persisted when comparing tramadol with other opioids; ROR: 2.13 (95% CI 1.52-2.99). Disproportionality was also observed in VigiBase^®: ROR 1.69 (95% CI 1.47-1.93).

Conclusion

Our study confirms, for the first time, a possible signal for a tramadol-hiccups association. Nevertheless, observational analytical studies are needed to confirm these results.

Plain Language Summary

Evaluation of the relationship between the tramadol and the risk of hiccupsIntroduction: Hiccups are sudden involuntary contractions of the diaphragm. This involuntary contraction causes the vocal cords to close very briefly, which produces the characteristic sound of a hiccup. Hiccups are usually benign and self-limiting, but can sometimes be persistent. If left untreated, they can provoke severe discomfort, depression, disability, and in the most extreme cases, even death. Drugs are a rare cause of hiccups.Methods: This study investigated the possible association between tramadol and hiccups (an unmentioned adverse drug reaction in the Summary of Product Characteristics) in the European pharmacovigilance database (EudraVigilance) and a confirming analysis in the World Health Organization pharmacovigilance database (VigiBase).Results: Our analysis shows that hiccups is relatively more frequently reported in association with tramadol than with other medicinal products, with EudraVigilance and VigiBase confirming this association.Conclusion: Tramadol is an opioid analgesic indicated, alone or in combination with dexketoprofen or paracetamol for pain with various causes, so healthcare professionals and patients should be aware of this possible association.