The effect of methotrimeprazine on arterial blood gases in human volunteers

Methotrimeprazine for the management of End-Of-Life Symptoms in Infants and Children

Objective: This retrospective chart review assessed the efficacy, dose, and safety of methotrimeprazine in palliating end-of-life symptoms in children and infants. Methods: A retrospective chart review was conducted of 18 hospitalized pediatric patients who were treated with methotrimeprazine in their last two weeks of life. Data collected included age, diagnosis, symptoms, methotrimeprazine dose, route, efficacy, and any documented adverse effects. Results: Patients’ ages ranged from 16 days to 17 years. Underlying conditions included malignancies, trauma, and various neurodegenerative and congenital diseases. All patients (n=18) were treated for symptoms of agitation, delirium, or restlessness. Most patients also experienced respiratory secretions/congestion (n=15), pain (n=13), and/ or dyspnea (n=9). Less common symptoms included nausea/emesis (n=5) and spasticity (n=1). Methotrimeprazine dosages ranged from 0.02 mg/kg/dose to 0.5 mg/kg/dose. Routes of administration included intravenous (n=13), oral/gastrostomy tube (n=6), or subcutaneous (n=4). Sedation (n=6) was the only documented adverse effect, although when agitation was present, this was potentially an intended and perceived-to-be-beneficial effect. Conclusion: Methotrimeprazine, an old drug with diverse receptor activity and multiple routes of administration, appears to be an effective tool in treating complicated end-of-life symptoms in children and infants. This study provides a foundation for analysis with prospective and comparative trials, which may further quantify its benefit.

Effect of secobarbital and morphine on arterial blood gases in healthy human volunteers

Secobarbital is still widely used as a hypnotic and morphine as an analgesic perioperatively in surgical patients. Their combination is often used as a preanesthetic medication. Although their ventilatory depressant effect is recognized, the resulting blood gas changes have not been studied as yet adequately in a sufficiently large population of healthy volunteers. Therefore this study was undertaken. Thirty healthy volunteers who gave valid written consent were studied. Secobarbital 2.0 mg/kg intravenously caused a significant (P < .05) decrease in arterial oxygen pressure (PaO2), peaking at 10 minutes (n = 10; mean age, 23.4 years). Morphine, 0.2 mg/kg intravenously also caused a significant decrease in PaO2 at 5 minutes (n = 10; mean age, 26.3 years). The combination of the same doses of morphine and secobarbital caused a significantly (P < .01) greater decrease in PaO2 at 5 and 10 minutes than the sole administration of either drug (n = 10; mean age, 23.5 years). Arterial oxygen pressure remained significantly (P < .05) reduced for 30 minutes. Although the PaCO2 increases after secobarbital and morphine did not reach statistical significance, their combination caused a significant (P < .05) increase in PaCO2. Both secobarbital and morphine alone caused significant (P < .05) decrease in pHa at 30 minutes. Their combination caused a significant (P < .01) reduction in pHa from 5 minutes until 60 minutes. In conclusion, both secobarbital and morphine alone caused ventilatory depression. The duration of ventilatory depression was greater with the intravenous combination than with either drug alone.