Chronic amitriptyline overdose in a child

Amitriptyline, a tricyclic antidepressant, has a well-described toxicity profile, and acute ingestions are common in the pediatric toxicology world. However, little can be found in the literature regarding chronic overdose. We describe a case of a 6-year-old girl who was prescribed amitriptyline 30 mg nightly for sleep problems, but was mistakenly given 300 mg (15 mg/kg) nightly for over a month. She was noted to have mental status changes and difficulty reading several days after starting the medication. She presented to the local children's hospital in status epilepticus with significant cardiac conduction abnormalities on ECG. Her total amitriptyline/nortriptyline level was found to be 1676 ng/mL (normal therapeutic level 50-300 ng/mL). She was treated for several days with sodium bicarbonate. Within 24 h, her neurologic status improved and had returned to baseline within several days. Her ECG normalized, and she was discharged home, without apparent sequelae. A brief discussion of possible protective mechanisms (including pharmacogenomic) is presented.     

Orbital metastasis in patients with rhabdomyosarcoma: case series and review of the literature

We present 3 cases of children who developed recurrent rhabdomyosarcoma with metastases to the orbit and review the medical literature. Eight additional cases have previously been reported. Alveolar rhabdomyosarcoma was diagnosed in 7 cases. All 11 patients had stage 3 or 4 tumors at diagnosis, but none had orbital involvement initially. The mechanism of orbital recurrence is hematogenous in nature. Ten of the patients died; 7 of them succumbed with progressive disease within 6 months of the orbital recurrence.     

What constitutes optimal therapy for patients with rhabdomyosarcoma of the female genital tract?

BACKGROUND: Factors affecting outcome for rhabdomyosarcoma (RMS) of the female genital tract in patients treated on Intergroup Rhabdomyosarcoma Study Group (IRSG) protocols I-IV were evaluated to define optimal therapy. METHODS: Records of 151 patients with tumors of the female genital tract who were treated on IRSG protocols I-IV were reviewed for details regarding chemotherapy, surgery, radiotherapy (RT), and outcome. RESULTS: The overall 5-year survival was 82%, (87% for patients with locoregional tumors). Chemotherapy was primarily vincristine, actinomycin-D, and cyclophosphamide (VAC) based. Local therapy was surgery alone in 42% of patients, surgery plus RT in 19% of patients, biopsy plus RT in 12% of patients, and biopsy without RT in 21% of patients. The rate of hysterectomy decreased from 48% in IRS-I/II to 22% in IRS-III/IV with an increase in the use of RT from 23% in IRS-II to 45% in IRS-IV and continued excellent survival. Many patients with vaginal primary tumors received delayed RT or had it omitted on later studies with excellent outcome. For patients with localized embryonal/botryoid tumors, there were no significant differences in 5-year survival among patients with tumors at different sites or among patients treated on IRS-I-IV. In patients with Group I-III tumors, 43% of deaths were from toxicity. Analysis of prognostic factors, with toxic deaths censored, revealed that an age of 1-9 years at the time of diagnosis, noninvasive tumors, and the use of IRS-II or IRS-IV treatments were associated significantly with better outcome. Patients ages 1-9 years fared best (5-year survival of 98%) and patients outside of this age range especially benefited from the intensified therapy used in IRS-III or IRS-IV (5-year survival of 67% on the IRS-I/II vs. 90% in IRS-III/IV). CONCLUSIONS: Localized female genital RMS usually is curable with combination chemotherapy, a conservative surgical approach, and the use of RT for selected patients.     

Treatment of orbital rhabdomyosarcoma: survival and late effects of treatment--results of an international workshop.

PURPOSE: Orbital rhabdomyosarcoma (RMS) historically has been associated with an excellent survival rate. The majority of patients are cured with the use of both chemotherapy and radiation therapy, but a significant number experience important late sequelae of treatment. In an attempt to determine optimal therapy in relation both to cure and to sequelae, the experience of the four international collaborative groups (Intergroup Rhabdomyosarcoma Study Group [IRSG], International Society of Paediatric Oncology [SIOP] Sarcoma Committee, German Collaborative Soft Tissue Sarcoma Group [CWS], and Italian Cooperative Soft Tissue Sarcoma Group [ICG] studies) was shared at an international workshop. PATIENTS AND METHODS: A total of 306 eligible patients were identified from group records (186 from IRS, 43 from SIOP MMT, 40 from CWS, and 37 from ICG). Median age was 6.8 years, and median follow-up was 6.5 years. Eighty percent of patients received radiation therapy (RT) as part of primary therapy, but there were significant differences in the use of RT between the individual groups (93% in IRSG, 76% in ICG, and 70% in CWS, but only 37% in the SIOP MMT group). RESULTS: At 10 years, event-free and overall survival for the whole cohort were 77% (range, 71% to 81%) and 87% (range, 82% to 92%), respectively. There was no difference in overall survival between the collaborative groups regardless of differences in the use of initial RT. In total, 34 (12%) of 273 survivors had not received RT, although this varied between the different groups (41% in the SIOP MMT group, 20% in CWS, 7% in ICG, and 6% in IRSG). There was no difference in overall survival for the whole cohort regardless of whether radiotherapy was used as part of initial therapy (86% at 10 years for both). CONCLUSION: These data suggest that a subset of patients with orbital RMS can be cured without systematic local therapy, although the total burden of treatment (primary therapy and treatment for relapse) must be taken into account when assessing the implications for late sequelae.     

Pharmacological zinc and phytase supplementation enhance metallothionein mRNA abundance and protein concentration in newly weaned pigs

The swine industry feeds pharmacological zinc (Zn) to newly weaned pigs to improve health. Because most swine diets are plant-based with a high phytic acid content, we hypothesized that adding phytase to diets could reduce the amount of Zn required to obtain beneficial responses. The role of metallothionein (MT) in Zn homeostasis could be important in this positive response. Thus, the goal of this study was to investigate the effect of dietary Zn and phytase on relative MT mRNA abundance and protein concentration in newly weaned pigs. Diets containing adequate (150 mg Zn/kg) or pharmacological concentrations of Zn (1000 or 2000 mg Zn/kg), as zinc oxide, with or without phytase [0, 500 phytase units (FTU)/kg, Natuphos, BASF] were fed in a 3 x 2 factorial design. Plasma and tissue minerals were measured in pigs killed after 14 d of dietary intervention. Hepatic and renal relative MT mRNA abundance and protein were greater (P < 0.05) in pigs fed 1000 mg Zn/kg with phytase, or 2000 mg Zn/kg with or without phytase vs. the remaining treatments. Intestinal mucosa MT mRNA abundance and protein were greater (P < 0.05) in pigs fed 2000 mg Zn/kg with phytase than in pigs fed 2000 mg Zn/kg alone or 1000 mg Zn/kg with phytase. Pigs fed 1000 mg Zn/kg plus phytase or 2000 mg Zn/kg with or without phytase had higher plasma, hepatic, and renal Zn than those fed the adequate Zn diets or 1000 mg Zn/kg. We conclude that feeding 1000 mg Zn/kg with phytase enhances MT mRNA abundance and protein and Zn absorption to the same degree as 2000 mg Zn/kg with and without phytase.