Propoxyphene-induced wide QRS complex dysrhythmia responsive to sodium bicarbonate--a case report

Propoxyphene overdose is known to cause widening of the QRS complex on ECG. We report a case of a 54-year-old female who ingested approximately 100 propoxyphene hydrochloride tablets in a suicide attempt. She developed a wide complex dysrhythmia which responded to sodium bicarbonate therapy. Propoxyphene-induced wide complex dysrhythmia responsive to sodium bicarbonate therapy has not been previously reported in the literature.

Effects of prenalterol on central hemodynamics and myocardial metabolism in experimental propoxyphene-induced shock

The hemodynamic and cardiometabolic effects of prenalterol were evaluated in propoxyphene-induced circulatory shock in 10 pentobarbital-anesthetized pigs. Circulatory shock (i.e. a systolic arterial blood pressure below 60 mmHg (8 kPa) and/or a cardiac index of less than 2.0 1 X min-1 X m-2) was induced by intravenous propoxyphene chloride 15 mg X min-1. Circulatory shock occurred after 26 +/- 3 mg X kg-1 of propoxyphene. During continuous infusion of propoxyphene, consecutive doses of prenalterol 0.5, 1.0, 2.0 and 4.0 mg i.v. were injected with an interval between increments of 8 min. The maximum effect of prenalterol was seen following the 2 mg dose. Increases were observed in mean arterial blood pressure, cardiac index, stroke volume index, left ventricular stroke work index, right ventricular stroke work index, maximum rate of rise of ventricular pressure, and total body oxygen consumption. Decreases were observed in pulmonary artery occlusion pressure, mean right atrial pressure and systemic vascular resistance, whereas heart rate and pulmonary vascular resistance remained unchanged. The cardiometabolic parameters: coronary sinus flow, coronary vascular resistance, myocardial oxygen consumption and extraction, remained low. Due to profound vasodilation, normal perfusion pressures were not reestablished. In conclusion, prenalterol improved cardiac performance by a significant positive inotropic action. However, pure inotropic stimulation was not sufficient to counteract the circulatory shock state during severe propoxyphene intoxication.

Ethanol does not increase lethality due to propoxyphene in rats

Male Wistar rats (210-330 g) were used as test animals. Propoxyphene (175 mg/kg) and ethanol (2 g/kg) were administered by gastric intubation, naloxone (2 mg/kg) by subcutaneous injection. Four groups, each consisting of 19 rats received either of the following drug treatments: Propoxyphene; ethanol + propoxyphene; naloxone + propoxyphene; and naloxone + ethanol + propoxyphene. The drugs were given in the sequence mentioned at the beginning of the experiment. Naloxone was also given 45 and 90 min later. Mortality was reduced to 42% in the group that received ethanol and propoxyphene as compared to 73% in the group that received propoxyphene only. Naloxone protected against lethality in both groups. A rise in the propoxyphene/norpropoxyphene (P/N) ratio due to an increase in the absolute concentrations of propoxyphene and a decrease in the absolute levels of norpropoxyphene in blood, brain and heart tissues was observed in the ethanol + propoxyphene group, compared to the propoxyphene group. Although these pharmacokinetic data indicate impaired propoxyphene metabolism in the presence of ethanol, ethanol did not enhance propoxyphene induced lethality. This is also contrary to suggestions from previous studies. Our results demonstrate that at least in one species and at one dose ratio (ethanol/propoxyphene) ethanol might reduce the lethality caused by propoxyphene alone. This suggests antagonism between the two drugs, probably in the central nervous system.

Circulatory shock following intravenous propoxyphene poisoning. An experimental study of cardiac function and metabolism in pentobarbital-anesthetized pigs

The effects of continuously administered intravenous propoxyphene chloride (15 mg X min-1) on ECG, systemic, pulmonary and coronary circulations and myocardial oxygenation were investigated in eight pentobarbital-anesthetized pigs. Circulatory shock, defined as a systolic blood pressure below 60 mmHg (8.0 kPa) and a cardiac output of approximately 2.0 l X min-1 X m-2, occurred after 675 to 2025 mg propoxyphene chloride. At the time when shock occurred plasma concentrations of propoxyphene ranged from 9.6 to 15.3 micrograms X ml-1 which is within the range of the lethal concentration observed in man. Statistically significant decreases were observed for the following variables: maximum rate of rise of left ventricular pressure dP/dt (-90%), mean arterial pressure (-73%), heart rate (-46%), cardiac index (-58%), stroke volume index (-22%), left ventricular stroke work index (-85%), right ventricular stroke work index (-63%) and systemic vascular resistance (-50%). Mean pulmonary arteriolar occlusion pressure increased (+42%), whereas mean right atrial pressure and pulmonary vascular resistance remained unchanged. The arteriovenous oxygen difference increased (+53%) and total body oxygen consumption decreased (-35%). The following coronary variables decreased: coronary sinus blood flow (-57%), coronary vascular resistance (-65%), myocardial oxygen consumption (-68%), myocardial oxygen extraction (-26%) and myocardial lactate extraction (-28%). Prolongation of the ECG PQ and QRS intervals were recorded shortly before shock appeared, and all animals were in sinus rhythm till the last minute before death. The results indicate that intravenously administered propoxyphene besides being a powerful negative inotropic and chronotropic agent, is also a potent systemic and coronary vasodilator.

Lack of evidence of increased lethality due to propoxyphene overdose in the presence of ethanol in male Wistar rats

The primary purpose of the present investigation was to evaluate if the presence of ethanol increased lethality induced by propoxyphene. A secondary aim was to study the effect of naloxone on propoxyphene lethality alone, and on the concomitant administration of propoxyphene and ethanol. Male Wistar rats (210-330 g) were used as test animals. Propoxyphene (175 mg/kg) and ethanol (2 g/kg) were administered by gastric intubation, naloxone (2 mg/kg) by subcutaneous injection. Four groups, each consisting of 19 rats, received either of the following drug treatments: Propoxyphene, ethanol + propoxyphene, naloxone + propoxyphene, and naloxone + ethanol + propoxyphene respectively. The drugs were given in the sequence mentioned at the beginning of the experiment. Naloxone was also given 45 and 90 min later. Mortality was reduced to 42% in the group that received ethanol and propoxyphene compared to 73% in the group that received propoxyphene only. Naloxone protected against lethality in both groups. Some animals died despite naloxone administration, possibly due to a nonopioid cardiotoxic effect of propoxyphene or its metabolite. An increase in the propoxyphene/norpropoxyphene (P/N) ratio due to an increase in the absolute concentrations of propoxyphene and a decrease in the absolute levels of norpropoxyphene in blood, brain, and heart tissues was observed in the ethanol + propoxyphene group, compared to the propoxyphene group. In the animals which died, the highest P/N ratio was observed in brain tissue and the lowest in heart muscle. Despite the pharmacokinetic data obtained in this investigation indicating impaired propoxyphene metabolism in the presence of ethanol, ethanol did not enhance propoxyphene-induced lethality.(ABSTRACT TRUNCATED AT 250 WORDS)

Liquid chromatographic determination of propoxyphene and norpropoxyphene in plasma and breast milk

A sensitive and specific high-performance liquid chromatographic (HPLC) procedure was developed for determination of propoxyphene and norpropoxyphene in plasma and breast milk. The compounds were isolated from the biological specimen by extraction, the organic phase was evaporated to dryness, and the residue was redissolved in mobile phase [acetonitrile: 0.002 M H2SO4 (1:1)]. The resultant solution was then injected into an HPLC system utilizing a C18 reversed-phase analytical column and a variable-wavelength detector set at 205 nm. Under these conditions the method has a sensitivity of 20 ng/mL using 1 mL of plasma or milk. The within-run coefficient of variation for both compounds varied between 6.2 and 8.9% within the concentration range tested. Applicability of the method was demonstrated in a nursing mother who received multiple oral doses of propoxyphene.

Acute propoxyphene self-poisoning in 222 consecutive patients

The course of severe propoxyphene self-poisoning in 222 consecutive patients is presented. On admission, 73% of the patients had neurological symptoms, 10% had convulsions, 45% were in respiratory failure, and impaired circulation was present in 48%. A mortality rate of 8% was observed. Twelve patients arrived in asystole of whom six were resuscitated without sequelae. The overdose was accidental in 13 patients, one of whom died. Early medical intensive care was found mandatory for a good prognosis. Before discharge from the ICU we recommend an observation-period free of cardiovascular symptoms for 24 h.

Left bundle branch block associated with propoxyphene hydrochloride poisoning

Described is the case of a patient who developed left bundle branch block following acute propoxyphene hydrochloride overdosage. The left bundle branch block was transient and associated with no permanent sequelae. Previously documented cardiac abnormalities, specific narcotic antagonist therapy, and animal studies correlating cardiac toxicity of propoxyphene hydrochloride with its potent local anesthetic action are discussed.

[Myopathy caused by propoxyphene: report of 2 cases with muscle histochemistry]

The cases of a 43 years old-man with gout and a 24 years-old woman with severe back pain who developed dextro-propoxyphene addiction during pain treatment are reported. They had severe edema and fibrosis of skin, subcutaneous tissue and muscle involving the upper and lower limbs. ESR was elevated, CPK and LDH were normal. EMG in proximal muscles showed decreased duration and voltage of potentials, excess of short polyphasics and increased recruitment (BSAP), with positive waves and fibrillations; distal muscles had fasciculations, fibrillations, positive waves, normal voluntary potentials, decreased recruitment. Lymphography indicate delayed progression of contrast media and obstruction in the thighs. Muscle biopsy on fresh-frozen section and histochemistry showed extensive connective tissue proliferation with intense acid and alkaline phosphatase activity in the perimysial and endomysial area, infiltration of lymphocytes near and around small vessels and capillaries. There were perifascicular and type II fiber atrophy. After discharge the patients returned to propoxyphene addiction and the symptoms who subsided during drug withdrawal come back again. New admission, new drug withdrawal and they were discharged free of symptoms and pathologic changes.

Cardio-respiratory toxicity of propoxyphene and norpropoxyphene in conscious rabbits

The toxic effects of alpha-d-propoxyphene (P) and its primary metabolite alpha-d-norpropoxyphene (NP) were compared to intravenous infusions (100 min.) of equimolar doses of P and NP (80 micronmol/kg equivalent to 30 mg/kg P HCl) in conscious rabbits. During P infusion severe respiratory depression and convulsions were seen in all animals, and six of the nine animals died. During NP infusion, however, only minimal respiratory depression was seen and all the animals survived. Considerable prolongation of the QRS complex and cardiac arrhythmias like intermittent A-V block and ventricular extrasystoles were seen in the ECG during both P and NP infusion, while the arterial blood pressure was unchanged. In P injection experiments (6 mg/kg P HCl), ECG changes preceded reduction in respiratory rate and during NP infusion only minor changes were seen in arterial blood gases, demonstrating that the ECG changes produced by P and NP are independent of respiratory depression. The ECG changes were found to be similar to those reported in quinidine intoxication. The QRS prolongation was markedly correlated with plasma concentrations during and after P and NP infusion. The results of the present investigation favour the hypothesis that the contribution of NP to the toxicity of oral P overdosage in man is ascribed to its cardiotoxic action whereas P is responsible for the CNS toxicity (respiratory depression and convulsions) as well as cardiotoxicity.

Plasma protein binding of d-propoxyphene in normal subjects and anephric patients

The free fraction of d-propoxyphene in the plasma of normal subjects is 0.24 +/- 0.02 (mean +/- S.D.) and is not concentration dependent in the usual therapeutic and toxic conentration range. Renal failure and relatively high concentrations of d-norpropoxyphene, the major metabolite of d-propoxyphene, have no significant effect on the plasma protein binding of d-propoxyphene.