ECG abnormalities in co-proxamol (paracetamol/dextropropoxyphene) poisoning.

Abstract

OBJECTIVES:

1) To investigate ECG changes following co-proxamol (paracetamol 325 mg and dextropropoxyphene 32.5 mg) overdose in comparison to co-codamol (paracetamol and codeine) or co-dydramol (paracetamol and dihydrocodeine) in a prospective study. 2) To examine the relationship between estimated dextropropoxyphene dose and ECG changes in a larger patient population.

BACKGROUND:

Co-proxamol is a common cause of drug-induced death and hospital admission in the United Kingdom. ECG changes following dextropropoxyphene have been reported in animals and man, including QRS prolongation.

METHODS:

The prospective study was conducted on 15 patients and controls with overdose. A retrospective study of a cohort of 159 co-proxamol overdoses from a combined data set from Edinburgh and Newcastle, Australia was also conducted. The measured or estimated "four hour" plasma paracetamol level was used as a surrogate of the amount of dextropropoxyphene ingested.

RESULTS:

In the prospective study co-proxamol overdose caused statistically significant QRS prolongation (mean [95% CI] 99.36 [96.19, 102.53] msec), compared to the other combination opioid-paracetamol products (82.84 [80.81, 84.88] msec) but no effect on PR or QTc. QRS duration increase was evident soon after exposure and remained prolonged and stable over the following 24 h. In the retrospective cohort study a dose dependency of effect on QRS was documented, although the correlation coefficient relating paracetamol level to effect was relatively weak (r = 0.338, Sig. [2-tailed] 0.003, n = 74).

CONCLUSIONS:

QRS is significantly prolonged in co-proxamol overdose, and this prolongation is dose dependent. These findings have clinical relevance to the management of patients with co-proxamol poisoning.

• Authors: R Afshari, S Maxwell, A Dawson, D N Bateman
• Journal: Clinical toxicology (Philadelphia, Pa.) (Clin Toxicol (Phila)) Vol. 43 Issue 4 Pg. 255-9 ( 2005) ISSN: 1556-3650 [Print] England
• PMID: 16035201 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Analgesics, Non-Narcotic
• Analgesics, Opioid
• Drug Combinations
• Acetaminophen
• dihydrocodeine
• Dextropropoxyphene
• Codeine

Topics

• Acetaminophen (poisoning)
• Adult
• Analgesics, Non-Narcotic (poisoning)
• Analgesics, Opioid (poisoning)
• Codeine (analogs & derivatives, poisoning)
• Dextropropoxyphene (poisoning)
• Drug Combinations
• Drug Overdose
• Electrocardiography (drug effects)
• Female
• Hemodynamics (drug effects)
• Humans
• Male
• Prospective Studies
• Retrospective Studies