PubMed Health⌕ Search

Biomedical subjects

S H Fuller

Publications and source records attributed to S H Fuller.

5 recordsLinked to original sources

INR elevation associated with diarrhea in a patient receiving warfarin.

OBJECTIVE: To report a case of international normalized ratio (INR) prolongation in a patient receiving warfarin who experienced several episodes of diarrhea. CASE SUMMARY: A 56-year-old white woman, previously controlled on warfarin therapy (INR 2.5-3.5) after aortic valve replacement, experienced six episodes of INR elevation, each associated with an acute bout of diarrhea lasting from one to four days. The patient had not received additional warfarin or new medications (including nonprescription medications and herbal remedies) prior to the episodes. The patient had no obvious signs of bleeding (except bruising on 1 episode) or signs of infection determined through physician evaluation of the patient and her stools. In addition, she had no diagnosis of liver disease or acute or chronic malabsorption. The patient did report that her dietary intake decreased to 25-50% of normal during these episodes of diarrhea, which may result in decreased vitamin K ingestion. DISCUSSION: This is one of the first case reports documenting a trend of INR elevation specifically with episodes of diarrhea. Since most of the common reasons for acute INR elevation have been eliminated, diarrhea with decreased oral intake are the most probable causes for these observed changes in the INR. Several reports suggest that acute diarrhea results in malabsorption of vitamin K, which can predispose patients taking warfarin to INR elevations, but in many of these reports patients had other risk factors for INR elevation. Although the effect of diarrhea on vitamin K absorption and the INR is difficult to quantify, the INR elevation reported here seemed to be directly associated with the duration of each diarrheal episode. CONCLUSIONS: Diarrhea episodes in patients receiving warfarin can result in prolongation of the INR and possible bleeding. Patients who experience diarrhea or decreased oral intake resulting in elevated INRs should have their INRs evaluated more frequently and their warfarin doses adjusted appropriately.

Acute Disease↗

Management of acetaminophen toxicity.

Acetaminophen poisoning is a significant medical problem in the United States and is frequently managed by family physicians. The primary clinical effect of acetaminophen poisoning is hepatotoxicity that occurs after ingestion of large single doses of acetaminophen or after ingestion of smaller doses in patients with hepatic metabolism that is altered by drugs or concurrent medical conditions. Hepatocellular damage is probably caused by accumulation of the toxic intermediate metabolite N-acetyl-p-benzoquinoneimine when hepatic glutathione stores are depleted. Treatment of acetaminophen poisoning consists of preventing gastrointestinal absorption of the drug, use of the antidote N-acetylcysteine and supportive care.

Acetaminophen↗

Vancomycin-induced histamine release and "red man syndrome": comparison of 1- and 2-hour infusions.

Vancomycin-induced "red man syndrome" (RMS) is mediated in part by histamine release, and its severity is correlated with the area under the plasma histamine concentration-time curve. Ten adult male volunteers participated in a randomized, double-blind, two-way crossover trial (1-week washout interval between regimens) to determine the effect of 1- and 2-h infusions of vancomycin (1.0 g) on histamine release and on the frequency and severity of RMS. The severity of RMS was classified a priori as mild, moderate, or severe from a combined score of pruritus and extent of erythema. Serial concentrations of histamine in plasma and concentrations of vancomycin in serum were measured at baseline and during and after each infusion. Of 10 subjects, 8 had evidence of RMS during the 1-h infusion (3 mild, 3 moderate, and 2 severe), whereas only 3 of the 10 subjects (all mild) had RMS during the 2-h infusion (P less than 0.05). The 1-h infusion was associated with a significantly greater peak concentration of histamine in plasma (1.8 +/- 0.7 versus 1.0 +/- 0.3 ng/ml, P = 0.004) and a greater total release of histamine (74.3 +/- 54.1 versus 36.4 +/- 22.6 ng.min/ml, P = 0.017) than was the 2-h infusion. These data suggest that administration of vancomycin over 2 h reduces the frequency and severity of RMS and the amount of histamine released compared with those after a 1-h infusion in healthy volunteers.

Adult↗

Stability of carbamazepine suspension after repackaging into four types of single-dose containers.

The stability of carbamazepine in commercially available suspension that had been repackaged in various single-dose containers was studied. Carbamazepine suspension was repackaged in 2-mL and 8-mL aliquots in amber glass vials, polypropylene vials, and amber polypropylene syringes and in 2-mL aliquots in amber glass oral syringes. Containers were stored at room temperature and continuously exposed to fluorescent light for up to 12 weeks. Samples from each container type and volume were assayed for carbamazepine content by high-performance liquid chromatography at various intervals during storage. Carbamazepine concentrations in the samples were compared with the carbamazepine concentration in the original manufacturer's container. The pH of the samples was also determined, and the suspensions were inspected for color, odor, and large particles. There was no significant decrease in carbamazepine concentration of more than 10% in samples stored for up to eight weeks. After 12 weeks, significant decreases in concentration were observed in all but one container type. No changes in color, odor, or consistency were observed during the 12 weeks, and there were no significant changes in pH. In commercially available suspension repackaged in volumes corresponding to common pediatric doses, carbamazepine (20 mg/mL) is stable for at least eight weeks when stored at room temperature in the containers tested.

Carbamazepine↗