A multiple drug intoxication involving cyclobenzaprine and ibuprofen

Acute Ibuprofen intoxication: report on a case and review of the literature

A fatality following the ingestion of ibuprofen is reported. Ibuprofen is a prototypical nonsteroidal anti-inflammatory drug widely prescribed as an analgesic, anti-inflammatory, and antipyretic agent. To date, there are few case reports of fatal overdose with ibuprofen, following ibuprofen self-poisoning or accidental overdose. We report the case of a 51-year-old man with medical history of psychiatric disease, who was brought to the emergency department by ambulance with a chief complaint of having taken large amounts of drugs in a suicide attempt.Multiple empty containers of medications (ibuprofen, meloxicam, celecoxib, risperidone, citalopram, ketorolac, bromazepam) were found at the scene. He died 4 hours after admission to the emergency department, despite vigorous supportive care. Toxicological analyses were performed using a gas chromatography/mass spectrometry technique. The estimated ibuprofen concentration in the plasma was 600 μg/mL; gastric content was 200 μg/mL for this compound. Our report describes results of the forensic investigation and discuss the review of the literature.

Cyclobenzaprine: a new look at an old pharmacological agent

Cyclobenzaprine is a tricyclic pharmacologic agent that has enjoyed considerable use since its availability. Most clinical usages have focused on the muscle relaxant properties, the mechanism of action being more recently redefined. Higher orders of the CNS are, nevertheless, affected, and the latter contributes to the spectrum of proclaimed side effects that are otherwise largely anticholinergic in nature. Cyclobenzaprine has a reasonable safety profile and overdoses are not as problematic as those for accepted tricyclic psychotherapeutic agents. Clinical studies have given supportive, albeit not conclusive, evidence for treatment roles in the short-term management of acute neck and back pain, and fibromyalgia. Further and more exacting science is warranted to explore the value of this drug in other neurological and psychiatric contexts.

Fatality after deliberate ingestion of sustained-release ibuprofen: a case report

INTRODUCTION

Ibuprofen is a nonsteroidal anti-inflammatory drug available over the counter and on prescription for the management of pain and inflammation. Severe toxicity is rare following deliberate self-poisoning with ibuprofen, and patients are usually either asymptomatic or develop only mild gastrointestinal toxicity. Although there have been nine other reported fatalities, co-existent factors have probably contributed to all of these deaths. We report here a fatality from isolated toxicity following self-poisoning with sustained-release ibuprofen.

CASE REPORT

A 26-year-old female presented after deliberate ingestion of up to 105 g sustained-release ibuprofen, with a reduced level of consciousness, severe metabolic acidosis and haemodynamic compromise. Despite intensive supportive management, gut decontamination with multidose activated charcoal and correction of the metabolic acidosis with sodium bicarbonate and haemofiltration, the patient did not survive. The ibuprofen concentration ante mortem on presentation in peripheral blood was 760 mg/l and the concentrations post mortem were 518 mg/l in peripheral blood, 74 mg/kg in liver extract and 116 mg/l in the gastric contents.

DISCUSSION

Most patients with ibuprofen poisoning are either asymptomatic or have mild gastrointestinal symptoms; severe poisoning with ibuprofen is rare. We report the first death related to isolated sustained-release ibuprofen poisoning.

Rhabdomyolysis: a manifestation of cyclobenzaprine toxicity

A case of cyclobenzaprine (flexeril) overdose and the resultant rhabdomyolysis is presented. A review of the range of clinical toxicity, management of overdose is described. The similarity of cyclobenzaprine to the tricyclic antidepressant class is emphasized; this report attempts to disseminate related information on this commonly prescribed centrally acting muscle relaxant.

Fatal blood and tissue concentrations of more than 200 drugs

Fatal drug concentrations in body fluids and tissue samples are presented for more than 200 drugs and chemicals of toxicologic interest. Additionally, a reference list is added with more than 600 original papers concerning intoxications with a lethal outcome. The data can be helpful for the interpretation and plausibility control in own cases of intoxication. However, they should be used with caution, because use of drug data without sufficient knowledge about the patient or victim, the circumstances of the case, and about toxicokinetics and toxicodynamics might give a wrong interpretation in a special case.

Torsade de pointes resulting from the addition of droperidol to an existing cytochrome P450 drug interaction

OBJECTIVE

To report a case of QT prolongation associated with concomitant cyclobenzaprine and fluoxetine administration followed by torsade de pointes potentiated by droperidol.

CASE SUMMARY

A 59-year-old white woman who had been receiving long-term fluoxetine and cyclobenzaprine therapy was admitted for Achilles tendon repair. Baseline QTc was prolonged at 497 msec. Prior to surgery, the patient received droperidol, an agent known to prolong the QT interval. During surgery the patient developed torsade de pointes, which progressed into ventricular fibrillation. On postoperative day 1, after cyclobenzaprine discontinuation, the QTc decreased toward normal (440 msec).

DISCUSSION

Cyclobenzaprine shares anticholinergic effects, tachycardia, and dysrhythmic potential with the tricyclic antidepressants (TCAs). Fluoxetine is a known inhibitor of the CYP2D6 isoenzyme (along with CYP3A4 and CYP2C) and has been shown to increase TCA serum concentrations. The combination of cyclobenzaprine and fluoxetine resulted in significant QT prolongation in our patient that progressed to torsade de pointes after preoperative droperidol administration. Resolution of QT abnormalities after cyclobenzaprine discontinuation provided further evidence of a drug-induced etiology. Other possible medical and drug-related causes of torsade de pointes are reviewed and ruled out.

CONCLUSIONS

Clinicians should be aware of the dysrhythmic potential of cyclobenzaprine and fluoxetine, monitor for other cytochrome P450 inhibitors, and avoid concomitant drugs known to prolong the QT interval.

Five-year multicenter retrospective review of cyclobenzaprine toxicity

Cyclobenzaprine (CBP) has a cyclic structure similar to amitriptyline. In overdose, CBP has been suggested to produce the cardiovascular and neurologic toxicity found with the cyclic antidepressants. To examine this possibility, a retrospective chart review of all cases of CBP exposure reported to five regional poison centers was performed for the years 1989-93. There were a total of 750 charts identified for CBP exposure, of which 523 had data sufficient for evaluation. There were 121 polydrug ingestions leaving 402 pure CBP ingestions. Ages ranged from 7 mo to 77 yrs, with a mean of 20 yrs; 26% were 6 yrs or less. Females comprised 63% of the patient group. No deaths occurred. Dysrhythmias beyond sinus tachycardia were infrequent, and none were life-threatening. No seizures occurred. Common effects were lethargy, sinus tachycardia, and agitation, and both hypertension and hypotension were seen. All symptomatic cases with a known time of ingestion were symptomatic within 4 h of ingestion. Doses ingested ranged from 5-1000 mg, with a mean of 133 mg. Asymptomatic and symptomatic patients had a mean dose ingested of 45 mg and 183 mg, respectively. Treatment was primarily gastrointestinal (GI) decontamination and supportive care. Other therapies required were mechanical ventilation, dopamine, fluid bolus, sedation, and foley catheter. Symptoms requiring treatment beyond GI decontamination did not occur with ingestions less than 100 mg. In conclusion, cyclobenzaprine does not appear to produce the life-threatening cardiovascular or neurologic effects of the cyclic antidepressants in doses less than 1 g. Lethargy and anticholinergic effects are prominent, though serious toxicity is infrequent.