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Physicians who prescribe viscous lidocaine preparations should be aware of the adverse effects and the high risk for overdose in pediatric patients. Owing to altered pharmacokinetics (increased absorption, decreased clearance, and prolonged half-life), doses that are innocuous for adults may present a significant potential toxic hazard in children. Lidocaine should not be used to treat painful mouth lesions in children until further safety data are available. Benzocaine may be considered as a safe alternative to lidocaine. Its low incidence of side effects makes it a safer choice for infants and children. If no other choices are appropriate, then very specific instructions should be given to parents. The amount, frequency, maximum daily dose, and mode of administration should be clearly communicated (eg, cotton pledget to individual lesions, one-half dropper to each cheek every four hours, or 20 minutes before meals). They should never be prescribed on a "PRN" basis.

Objective: To review the as-needed dosing of antipsychotic drugs. Because insufficient data are available to evaluate this therapy, alternative strategies in managing acute agitation in elderly patients are suggested., Data Sources: A MEDLINE search of English-language articles published between 1966 and June 1992 was used to identify studies and reviews of antipsychotic drugs administered in single doses or intermittently., Study Selection: Because of the paucity of data, all studies obtained were reviewed. Those addressing the use of drug holidays (chronic dosing with days without drug) were excluded., Data Extraction: No data are available regarding the efficacy of as-needed dosing of antipsychotics in elderly agitated patients; thus, data obtained from treating acutely psychotic patients are described, and differences between this population and elderly agitated patients are discussed., Data Synthesis: Antipsychotics are used frequently to control agitated behavior in elderly patients, although double-blind studies have not consistently demonstrated the superiority of active drug over placebo., Conclusions: Rigorous placebo-controlled trials of the safety and efficacy of as-needed dosing of antipsychotics are needed. As-needed dosing of any drug to control behavior should be reserved only for infrequent, sustained agitation that cannot be linked to an eliciting event. Orders for such dosing must include definitive, detailed directions for nursing personnel specifying target behaviors, maximum daily dosages, and monitoring parameters for assessing efficacy and adverse effects.

Objective: The purpose of this study was to determine the relative delivery of ciprofloxacin through a small-bore feeding tube (8 fr, 106 cm, Argyle)., Design: Ciprofloxacin 750-mg tablets were individually ground in a mortar and dissolved in 50 mL of water. Each resulting solution was drawn into a syringe and injected into a glass beaker (n = 10) or through a feeding tube into a beaker (n = 10) over one minute. Syringe apparati were flushed with two 60-mL portions of water. Aliquots from each of the 20 beakers were taken in triplicate, diluted 1:1000 with water, and assayed by HPLC., Results: Ciprofloxacin concentrations (mean +/- SD) for the samples without and with feeding tubes were 11.77 +/- 0.78 mumol/L and 12.16 +/- 0.65 mumol/L, respectively. The 3.3 percent difference is statistically significant (p = 0.04), but clearly is not clinically significant., Conclusions: Administration of crushed ciprofloxacin through a small-bore feeding tube in the manner described does not result in any measurable loss of drug delivered to the gastrointestinal tract.

We studied five children with carbamazepine overdose. Two patients had acute overdose without previous exposure to carbamazepine while three presented with acute-on-chronic overdose. Multiple doses of activated charcoal were administered to four patients. One acute-on-chronic patient did not receive any activated charcoal. The mean half-life of carbamazepine was as follows: a) Acute vs. Acute-On-Chronic overdose: 8.63 h vs. 12.01 h (p less than 0.05); b) No Activated Charcoal vs. 30-50 g Activated Charcoal vs. 60-90 g Activated Charcoal: 23.3 h vs. 10.17 h vs. 7.21 h (p less than 0.05); c) No Activated Charcoal vs. 2-3 doses vs. 7-12 doses: 23.3 h vs. 8.96 h vs 7.55 h (ns). Although the half-life of carbamazepine decreased in a linear relationship with the total amount of activated charcoal administered (r = -0.86), there was no relationship between the time to complete recovery and administration of multiple doses of activated charcoal. Although multiple doses of activated charcoal increased the clearance of carbamazepine in our patients with overdose, it was not associated with clinical benefits.

Measuring the monoethylglycine xylidide (MEGX) serum level 15-30 min after intravenous administration of lidocaine has been shown to be an accurate predictor of early success in liver transplants. This study evaluates the changes in the MEGX formation test associated with changes in liver mass and ethanol pretreatment in a rat model. Mean MEGX levels were significantly higher for the sham-operated group versus each of the partially hepatectomized groups at 15, 30, and 45 min after injection. No differences between mean MEGX levels for either of the surgically treated groups could be distinguished. Ethanol pretreatment and body weight had no effect on MEGX levels at any of the time points tested in this model.

Iofetamine hydrochloride I 123 permits cerebral blood perfusion imaging with single photon emission computed tomography (SPECT). SPECT is more widely available than positron emission tomography, and complements anatomic visualization with X-ray computed tomography (CT) or magnetic resonance imaging. Iofetamine is an amphetamine analog that is rapidly taken up by the lungs, then redistributed principally to the liver and brain. The precise mechanism of localization has not been determined, but is believed to result from nonspecific receptor binding. Brain uptake peaks at 30 minutes postinjection and remains relatively constant through 60 minutes. The drug is metabolized and excreted in the urine, with negligible activity remaining at 48 hours. When compared with CT in stroke patients, visualization may be performed sooner after symptom onset and a larger zone of involvement may be evident with iofetamine. Localization of seizure foci and diagnosis of Alzheimer's disease may also be possible. As CT has revolutionized noninvasive imaging of brain anatomy, SPECT with iofetamine permits routine cerebral blood flow imaging.