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Biomedical subjects

Joshua G Schier

Publications and source records attributed to Joshua G Schier.

11 recordsLinked to original sources

Preparing for chemical terrorism: stability of injectable atropine sulfate.

OBJECTIVE: A massive nerve agent attack may rapidly deplete in-date supplies of atropine. The authors considered using atropine beyond its labeled shelf life. The objective was to determine the stability of premixed injectable atropine sulfate samples with different expiration dates. METHODS: This was an in-vitro study using gas chromatography and mass spectrometry (GC/MS). Four atropine solutions (labeled concentration of 400 microg/mL) ranging from in date to 12 years beyond expiration (exp) and an additional sample of atropine sulfate (labeled concentration of 2,000 microg/mL) obtained from a World War II era autoinjector were assayed for atropine stability. Standards of atropine sulfate and tropine were prepared and quantified by GC/MS. Study samples were prepared by adding a buffer solution to free the base, extracting with an isopropanol/methylene chloride mixture and followed by evaporating the organic layer to dryness. Pentafluoropropionic anhydride and pentafluoropropanol were then added as derivatization reagents. Study samples were heated, the derivitization reagents were evaporated, and the remaining compound was reconstituted in ethyl acetate for injection into the GC/MS. RESULTS: All solutions were clear and colorless. Atropine concentrations were as follows: in date, 252 microg/mL; 2001 exp, 290 microg/mL; 1999 exp, 314 microg/mL; 1990 exp, 398 microg/mL; and WW II specimen, 1,475 microg/mL. Tropine was found in concentrations of <10 microg/mL in all study samples. CONCLUSIONS: Significant amounts of atropine were found in all study samples. All samples remained clear and colorless, and no substantial amount of tropine was found in any study sample. Further testing is needed to determine clinical effect.

Antidotes↗

Efficacy of Crotalidae polyvalent antivenin for the treatment of hognosed viper (Porthidium nasutum) envenomation.

Envenomation from pit vipers native to North America can be treated successfully with either of the 2 commercially available antivenoms licensed in the United States. However, envenomations from imported snakes held in zoos or private collections often pose unique challenges to management because of the lack of specific antivenom and the unclear efficacy of the available licensed products. We report the case of a 37-year-old man who was envenomated on his left hand by his pet hognosed viper (Porthidium nasutum ). He had swelling at the wound site that progressively worsened over 3 to 4 hours. His symptom progression included the structural motor impairment of his fingers and a sensory deficit. Treatment with 8 vials of Antivenin (Crotalidae) polyvalent was associated with a halt of extremity swelling and restoration of neurologic and motor function of his hand. Limited experimental evidence provides support for antigenic cross-reactivity between Antivenin (Crotalidae) polyvalent and P nasutum venom.

Adult↗

Ephedrine-induced cardiac ischemia: exposure confirmed with a serum level.

The temporal association of symptoms consistent with ephedrine toxicity after ingestion of ephedrine-containing dietary supplements is heavily relied upon to confirm exposure. Few reports in the literature attempt to associate toxicity with serum levels of these drugs. We report a case of ephedrine-induced cardiac ischemia confirmed by a plasma level. A 22-year-old woman ingesting an ephedrine- and caffeine-containing product for 2 days presented with multiple symptoms, including palpitations, nausea, tremulousness, abdominal pain, and vomiting. The initial electrocardiogram (ECG) revealed a normal sinus rhythm with 1 mm of ST segment depression in leads V3 and V4, along with inverted T waves in leads V1-V4. Her symptoms and ST segment depression resolved over several hours with medical management. The amplitude of her T wave inversions notably diminished with therapy; however, they did not completely resolve. Troponins at presentation and the following morning were negative, and an echocardiogram showed only trace tricuspid regurgitation. A serum ephedrine level, drawn approximately 6 to 7 hr after ingestion, was 150 ng/mL. She was discharged from the hospital after being instructed to avoid ephedrine-containing products.

Adult↗

Fatality from administration of labetalol and crushed extended-release nifedipine.

OBJECTIVE: To report a case in which a crushed extended-release (XL) nifedipine tablet contributed to a patient fatality. CASE SUMMARY: A 38-year-old woman with multiple medical problems presented to the hospital in acute respiratory distress and was diagnosed with acute pulmonary edema and pneumonia. After initial stabilization, her medications were changed to oral hydralazine, labetalol, and nifedipine XL. These medications were crushed and administered through a nasogastric tube. The patient developed worsening bradycardia with hypotension and experienced asystolic cardiac arrest. She was resuscitated; however, the following morning, another dose of labetalol and nifedipine XL was crushed and administered through the nasogastric tube. She again developed worsening bradycardia with hypotension and ultimately died. DISCUSSION: The administration of a crushed nifedipine XL tablet resulted in the patient's severe hypotension. The concurrent administration of labetalol prevented a compensatory heart rate increase. The repeat administration of nifedipine XL in the same manner underscores a fundamental problem in healthcare worker communication and drug delivery system comprehension. Use of the Naranjo probability scale indicated a highly probable relationship between the patient's hypotension and the nifedipine and labetalol therapy. CONCLUSIONS: Simultaneous administration of a beta-blocker and a calcium-channel blocker may produce synergistic effects. The release characteristics of oral controlled-release medications are destroyed when crushed, resulting in the rapid bioavailability of the total drug amount. The importance of education and communication among nurses, physicians, and pharmacists regarding the mechanism of action of controlled-release medications and their administration needs to be emphasized.

Administration, Intranasal↗

Desiccant-induced gastrointestinal burns in a child.

Desiccants are commonly composed of non-toxic chemicals such as silica gel. A 2-y-old male unintentionally ingested the contents of a desiccant packet found in a container of imported Chinese cookies. He presented with vomiting, drooling and inability to drink. A caustic injury to his tongue and phaynx was noted. He improved over the next 12 h and was discharged a day later. The packet was found to contain caustic lime Although patients who ingest desiccant packets generally develop no clinical effects, ingestion of packets containing strong alkali may prove consequential. Providers should be aware of the potential for this toxicity before dismissing desiccant exposures as benign.

Burns, Chemical↗