Drug-induced prolongation of the QT interval
Cases of intentional overdose have been reported in connection with taking loperamide. Abuse and misuse of loperamide as an opioid substitute have been described in individuals with opioid dependency. Cases of drug withdrawal syndrome have been observed following discontinuation in individuals overdosing on loperamide (Ref. 2).
Incident data |
Description |
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Year: 2022 Age: Age: 35 Sex: Female Medicinal product: Loperamide Indication: Chronic diarrhoea ADR: QT prolongation; overdose; drug dependency; opiate withdrawal symptoms |
The case literature (Ref. 1) reports a female patient with severe existing mental health issues and moderate intellectual disability who developed a substance use disorder while taking loperamide for chronic diarrhoea. With daily consumption of up to 60 mg per day, tests of the patient's metabolisation profile were carried out, which found strongly reduced CYP3A and p-glycoprotein activity. These are heavily involved in loperamide metabolisation and transport. The resulting increased bioavailability of loperamide in this patient may therefore have contributed to the substance use disorder. She developed loperamide dependency after overdose, with QT prolongation and opioid withdrawal symptoms. |
Year: 2015 Age: 46 Sex: Male Medicinal product: Loperamide Indication: Irritable bowel syndrome ADR: Overdose |
Male patient with loperamide dependency after overdose in the context of irritable bowel syndrome, taking up to 120 tablets (240 mg) daily, with occasional somnolence and a strong thirst. Acute diarrhoea, intestinal colic and anxiety on discontinuation of treatment, probably connected with the clinical picture of withdrawal syndrome.
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Ref. 1) Crettol S et al.: Opioid Use Disorder Associated With Low/Moderate Dose of Loperamide in an Intellectual Disability Patient With CYP3A and P-Glycoprotein Reduced Activity. Front Psychiatry.
Ref. 2) Medicinal product information (swissmedicinfo.ch)
Loperamide can be abused as an intoxicant. Prolongation of the QT interval and the QRS complex and/or severe ventricular arrhythmia, including torsades de pointes, have occurred in individuals who have intentionally overdosed on loperamide.
In the event of an overdose, ECG monitoring should be carried out with regard to prolongation of the QT interval. Treatment is symptomatic. Naloxone can be administered as an antidote in the event of CNS symptoms following overdose.
