Fatal poisonings in Finland during the years 2004-2009

Fatal alcohol and drug poisonings in Finland during the years 2004-2009 were studied. Cases were divided into those that occurred outside the hospitals (the majority of cases) and those that occurred within the hospitals (the minority of cases). Differences and similarities between the two groups were analysed. The postmortem toxicological investigation of all sudden and unexpected deaths in Finland is centralised at the Department of Forensic Medicine, University of Helsinki. We examined each fatal poisoning separately and verified the cause and place of death as well as the age and sex of the deceased. Fatal poisonings, including suicides, have remained unchanged for many years from the same high level, that is, about 1200 cases annually (22/100,000 inhabitants). The number of patients dying in hospitals due to poisoning has also remained stable (55-70 patients/year). However, the toxic agents involved in such poisonings have changed and deaths due to opioids are now being more numerous. The number of fatal unintentional drug poisonings rose significantly from 191 to 341 (3-6/100,000 inhabitants, p < 0.001) during the study years, and the difference between poisonings caused by drugs or alcohol also changed significantly (p < 0.001). Diminishing substantially, the number of all fatal poisonings will be challenging because of the high percentage of suicides. However, a reduction in unintentional drug overdoses, which are presently on the rise, should be possible.

Developmental pharmacokinetics of ciclosporin--a population pharmacokinetic study in paediatric renal transplant candidates

AIMS

To use population pharmacokinetic modelling to characterize the influence of developmental and demographic factors on the pharmacokinetic variability of ciclosporin.

METHODS

Pharmacokinetic modelling was performed in NONMEM using a dataset comprising 162 pretransplant children, aged 0.36-17.5 years. Ciclosporin was given intravenously (3 mg kg(-1)) and orally (10 mg kg(-1)) on separate occasions followed by blood sampling for 24 h.

RESULTS

A three-compartment model with first-order absorption without lag-time best described the pharmacokinetics of ciclosporin. The most important covariate affecting systemic clearance (CL) and distribution volume (V) was body weight (BW; scaled allometrically), responsible for a fourfold difference in uncorrected ciclosporin CL and a sixfold difference in ciclosporin V. The other significant covariates, haematocrit, plasma cholesterol and creatinine, were estimated to explain 20-30% of interindividual differences in CL and V of ciclosporin. No age-related changes in oral bioavailability or in BW-normalized V were seen. The BW-normalized CL (CL/BW) declined with age and prepubertal children (<8 years) had an approximately 25% higher CL/BW than did older children. Normalization of CL for allometric BW (BW(3/4)) removed its relationship to age.

CONCLUSION

The relationship between CL and allometric BW is consistent with a gradual reduction in relative liver size, until adult values, and a relatively constant CYP3A4 content in the liver from about 6-12 months of age to adulthood. Ciclosporin oral bioavailability, known previously to display large interindividual variability, is not influenced by age. These findings can enable better individualization of ciclosporin dosing in infants, children and adolescents.

A randomized trial of rizatriptan in migraine attacks in children

OBJECTIVE

To examine the efficacy of rizatriptan and the consistency of treatment response in migraine attacks of children and adolescents.

METHODS

We conducted a double-blind, placebo-controlled three-way crossover trial in patients ages 6 to 17 years diagnosed with migraine in two pediatric hospital outpatient clinics. Two doses of rizatriptan and a matching placebo were administered at home during three attacks. Rizatriptan dose was 5 mg for those with a body weight of 20 to 39 kg, and 10 mg for those with a body weight of 40 kg or more. The primary efficacy endpoint was headache relief by two grades on a five-grade face scale at 2 hours.

RESULTS

Ninety-six patients used all three treatments, 10 used two, and 10 only the first. At 2 hours, the primary endpoint was reached twice as often after both treatments of rizatriptan (first 74%, n = 71/96; second 73%, n = 70/96) as after placebo (36%, n = 35/96) (p < 0.001). Already at 1 hour, rizatriptan was clearly more effective as headache relief was reported by 50% (n = 48/96) and 55% (n = 53/96) of children after the first and the second dose of rizatriptan, compared to 29% (n = 28/96) after placebo (p = 0.004). Rizatriptan was superior at 3 and 4 hours, and the other endpoints also favored rizatriptan. Efficacy of rizatriptan was constant over the two treated attacks, and the findings were similar in children using the dose of 5 and 10 mg. No serious adverse effects were observed.

CONCLUSIONS

Oral rizatriptan is effective and well-tolerated for migraine attacks in children over age 6 years.

Migraine attacks and sleep in children

Falling asleep as a means of ending migraine attack was studied in 133 4-16-year-old children in out-patient settings. Children registered 999 migraine attacks in headache diaries using a visual analogue scale (VAS) in 409 attacks and a five-face scale in 590 attacks. The distribution of maximal pain intensity was similar on both scales; on VAS 88% assigned grades between 63 and 100, and on the face scale 93% assigned grades of 4 or 5. Children fell asleep during 33% of the attacks (n = 329), in 64% of these within the first hour (n = 209). Of the children, 68% (n = 91) had fallen asleep at least once during an attack. Falling asleep was more common in children under 8 years of age than in older children. In those under 8 years, 62% (95% confidence interval (CI) 49-75%) of attacks were resolved by sleep, in those aged 8-12 years 34% (26-41%), and in children >12 years 24% (15-33%) (ANOVA, P<0.0001). Pain was relieved without sleep in 43% (n = 431) of attacks, in 38% of these (n = 383) within the first 4 h. The data on migraine resolution were missing for 24% (n = 239) of the attacks, most often because the attack exceeded the 5-h observation period. This study confirms that migraine attacks in children are extremely painful and often resolve during an interval of sleep in children under 8 years of age.

Patient recruitment--European perspective

A considerable number of patients have to be recruited in a clinical trial to obtain solid results. In pediatric studies, patient recruitment is frequently problematic. In the simple common childhood illnesses, the number of recruitable patients is certainly large, but they may be hard to reach, and the imbalance between potential benefit and inconvenience of participation may reduce motivation to enroll. In severe diseases, the balance may be right, but the available number of patients may be small. Good communication with the child and family, as well as the motivation of colleagues to admit, is another key element in success. Proper study design, including realistically identified sources of patients, reasonable inclusion, and exclusion criteria, also are required.

The efficacy of lamotrigine in children and adolescents with refractory generalized epilepsy: a randomized, double-blind, crossover study

PURPOSE

We report a double-blind, placebo-controlled crossover study of lamotrigine (LTG) as add-on treatment in therapy-resistant, generalized epilepsy in children and adolescents (n = 30).

METHODS

Twenty patients had Lennox-Gastaut syndrome. Each patient acted as his or her own control. LTG and placebo were randomly added to existing antiepileptic medication (AEDs). The LTG dosage was individualized in an open phase preceding the placebo/treatment phase. Patients who responded to LTG in the open phase went on to the double-blind phase. "Responders " were defined as patients with a >50% seizure reduction or less severe seizures or both, or improved behavior or improved motor skills or both. "Nonresponders" were defined as children who showed no positive effects of LTG with plasma levels of < or = 10 microg/ml or children who had adverse events during the open phase.

RESULTS

There was a clear statistically significant reduction of seizure frequency in LTG compared with placebo treatment. None of the children studied showed abnormal biochemical or hematologic findings, or changes in plasma levels of concomitantly administered AEDs.

CONCLUSIONS

LTG is a well-tolerated and effective treatment in children with intractable generalized epilepsies, including those with Lennox-Gastaut syndrome. The study design allowed a double-blind placebo-controlled assessment of LTG although the participating children used 19 different AED combinations at entry.

Kidney function after 1:1 conversion to the cyclosporine microemulsion formulation in children with liver allografts

BACKGROUND

One-to-one (mg:mg) conversion from the conventional to the microemulsion formulation of cyclosporine (CsA) is advocated as a simple way to use the new therapeutic regimen. However, the potentially harmful effects of the conversion on kidney function in nonrenal transplant recipients are poorly known.

METHODS

Renal effects of the conversion were prospectively investigated in 22 pediatric liver transplant recipients (mean age, 8.4 years; mean time from transplantation, 3.2 years). Patients were followed for 12 months. Pharmacokinetic studies were performed at baseline and 5 days and 6 and 12 months after conversion.

RESULTS

Peak concentration, minimum concentration, average steady state concentration, and area under the concentration-versus-time curve increased by 60-130% after conversion. Graft losses, progressive deterioration of graft function, and acute rejection episodes did not occur. The mean glomerular filtration rate (GFR) was 103 ml/min/1.73 m2 at baseline and 100 ml/min/1.73 m2 after 12 months. However, 6 of the 22 patients showed at least a 15% (range, 16-38%) decrease in GFR between baseline and 6 months (P<0.01). They had a significantly higher increase in average steady state concentration between baseline and 6 months than the six patients with the best outcome in GFR during the same time period (164 ng/ml vs. 53 ng/ml, P<0.05). At this point (6 months), target CsA trough levels were reduced by 20-30%, while the mean area under the concentration-versus-time curve remained above that obtained at baseline. The GFR of three of the six patients subsequently improved.

CONCLUSIONS

One-to-one conversion can be performed safely in liver transplant recipients if strict follow-up is feasible.

Cyclosporin pharmacokinetics in paediatric transplant recipients

Cyclosporin is an essential component of the antirejection drug protocol used in the long term management of paediatric organ transplant recipients. This article looks at the pharmacokinetics of cyclosporin in paediatric kidney, heart, liver and bone marrow transplant recipients and critically evaluates its relationship to pharmacokinetic data in adult transplant recipients. There are limited data on the pharmacokinetics of cyclosporin in paediatric transplant recipients (14 publications provide the database) as compared with the adult transplant population. Study design, analytical methodology and age ranges of the individuals differ between studies, making comparative interpretation of pharmacokinetic data difficult. However, significant trends are noteworthy and these may influence dose administration guidelines and therapeutic monitoring standards for cyclosporin in the paediatric organ transplant recipient. The bioavailability of the oral formulations of cyclosporin is highly variable as with the adult population, but there appears to be a correlation between cyclosporin bioavailability and age with both the traditional oral formulation (Sandimmun) and the new microemulsion formulation (Neoral) in young liver transplant patients. Bowel length, presystemic metabolism in the gut wall, type of transplant and time since transplant are contributing factors in the variation of bioavailability patterns in paediatric transplant patients. The volume of distribution of cyclosporin does not appear to differ between paediatric and adult transplant recipients, but systemic clearance is comparatively higher in the paediatric population. In general, paediatric patients require higher doses of cyclosporin to achieve target blood concentrations of the drug which are equivalent to the values used in the adult population. Younger patients (less than 8 years of age) may be managed more effectively with a 3 times daily administration schedule rather than the twice daily schedule which is universally used for cyclosporin in the transplant population. The comparatively higher doses and more frequent administration schedule used in paediatric transplant recipients are the consequence of age-related differences in bioavailability and the possibility of increased metabolic clearance of the drug in younger patients.

Sumatriptan for migraine attacks in children: a randomized placebo-controlled study. Do children with migraine respond to oral sumatriptan differently from adults?

Oral sumatriptan is an effective acute treatment for migraine in adults, but its efficacy in children is still undetermined. Twenty-three children, aged 8.3 to 16.4 years, took both sumatriptan and placebo in a randomized, double-blind, placebo-controlled, crossover trial. The primary endpoint was a > or = 50% decrease in pain intensity on a 100-mm visual analogue scale at 2 hours. Other endpoints of efficacy were pain intensity difference (PID), showing pain relief at each time point; summed pain intensity differences (SPIDs), estimating overall pain relief; and preference. Two hours after sumatriptan, 7 of 23 reached the primary endpoint, and after placebo, 5 of 23 (difference 9%, 95% CI for difference, -21 to 38%; p = ns). Within 2 hours, the headache disappeared completely in 5 of 23 children after sumatriptan and in 2 of 23 children after placebo (p = ns). Median PIDs were slightly better for sumatriptan between 0.5 and 4 hours (p = ns). Median SPIDs increased almost identically up to 2 hours. Thereafter, median SPIDs for placebo remained practically constant, whereas for sumatriptan, the improvement continued. At 4 hours, the median SPID for sumatriptan was 2.4 times as high as for placebo. However, the maximum differences between median SPIDs at 4 hours (38.5, 95% CI, -75.8 to 57.5; Wilcoxon signed rank test, p = 0.4) or at any other point were not statistically significant. Of the 23 children, 13 preferred sumatriptan and 2 placebo (sign test, p = 0.004). The failure of this and previous controlled studies suggests that the response of children to sumatriptan may be different from adults.

Oral dihydroergotamine for therapy-resistant migraine attacks in children

Twelve children with migraine symptoms that did not respond to conventional analgesics completed a double-blind, placebo-controlled, cross-over study of two doses of oral dihydroergotamine (DHE) for acute treatment. The primary endpoint was reduction of headache by > or = 2 grades on a 5-grade scale at 2 hours. After DHE, 7 of the 12 children reached the primary endpoint, and 2 reached the primary endpoint after placebo [difference 42%; 95% confidence interval (CI) 14%-70%]. Five of the 7 were pain-free after DHE (3 with 20 micrograms/kg; 2 with 40 micrograms/kg); none was pain-free after placebo. Headache recurred in 2 of the 5. Although headache recurrence limits the efficacy of oral DHE, it may be useful in the acute treatment of migraine in selected children.

Methylprednisolone exposure, rather than dose, predicts adrenal suppression and growth inhibition in children with liver and renal transplants

Some patients receiving glucocorticoids develop adverse effects even with very low doses, whereas others fail to achieve the desired effects with the usual therapeutic doses. We hypothesized that glucocorticoid exposure, rather than the dose, would predict the development of adverse effects in children receiving long-term glucocorticoid treatment. Sixteen liver and 10 renal transplant recipients on triple immunosuppression were studied. Serum total methylprednisolone (MP) and cortisol were determined before and up to 10 h after peroral MP administration. Heights were recorded 6 months before and after the study day. The MP dose (in milligrams per kilogram) was not correlated with the serum cortisol concentration or with the change in height SD score. The area under the serum MP time vs. concentration curve was inversely related to the serum cortisol concentration and to the height SD score, and was the best predictor of both adrenal function and growth. Dosing according to area under the serum MP time vs. concentration curve in children receiving long-term glucocorticoid treatment may substantially reduce the incidence of adverse effects without affecting therapeutic efficacy.

Ibuprofen or acetaminophen for the acute treatment of migraine in children: a double-blind, randomized, placebo-controlled, crossover study

Efficacy of drugs for the acute treatment of migraine in children has not so far been studied in well controlled trials. We conducted a study to evaluate the efficacy of acetaminophen and ibuprofen. Eighty-eight children, aged 4.0 to 15.8 years, with migraine participated in a double-blind crossover study. Three attacks per child were treated in random order with single oral doses of 15 mg/kg acetaminophen, 10 mg/kg ibuprofen, and placebo at home. The primary end point, reduction in severe or moderate headache (grade > or = 3 on a scale of 1 to 5) by at least two grades after 2 hours, was reached twice as often with acetaminophen and three times as often with ibuprofen as with placebo. Ibuprofen was twice as likely as acetaminophen to abort migraine within 2 hours. In the intent-to-treat analysis, children improved twice as often with ibuprofen and acetaminophen as with placebo. Both ibuprofen and acetaminophen are effective and economical treatments for severe or moderate migraine attacks in children. Ibuprofen gave the best relief.

Pharmacokinetic interactions between lamotrigine and other antiepileptic drugs in children with intractable epilepsy

PURPOSE

We wished to determine the oral pharmacokinetics of lamotrigine LTG and to assess possible interactions with other AEDs in an unselected population of children. Concentration data in plasma and in CSF for lamotrigine as well as for the other AEDs are presented.

METHODS

Thirty-one children, children and young adults aged > 2 years with intractable generalized epilepsy despite adequate duration and dose of at least three conventional AEDs were studied.

RESULTS

There was a linear relation between the dose administered and the maximal plasma concentration, indicating that saturation of absorption or elimination mechanisms did not occur in the dose range studied. The median elimination half-life (t1/2) in patients receiving concomitant valproate (VPA) was 43.3 h; in patients receiving carbamazepine (CBZ) and/or phenobarbital (PB), it was 14.1 h; and in patients receiving both VPA and CBZ/ PB or other antiepileptic drugs (AEDs), it was 28.9 h. No clinically important changes in the plasma levels of CBZ, VPA, valproate, ethosuximide, or PB were observed in the follow-up period (2-12 months). No dose adjustments of concomitant AEDs were necessary. The plasma concentration of clonazepam (CZP) was reduced when LTG was introduced.

CONCLUSIONS

The complex interaction between LTG and other AEDs in children with intractable epilepsy makes therapeutic drug monitoring (TDM) desirable.

Comparison of conventional oral cyclosporine and cyclosporine microemulsion formulations in children with a liver transplant

We studied 22 children (mean age: 8.42 years, range: 1.9-15.6 years) with a liver transplant to compare the pharmacokinetics of oral cyclosporine (CsA) microemulsion to the conventional formulation. The CsA treatment (mean dose: 5.9 mg/kg/day, range: 3.0-11.7 mg/kg/day) was converted 1:1 on a milligram-to-milligram basis to the microemulsion formulation. Five days after the conversion, the mean peak blood CsA concentration was higher (microemulsion: 963 ng/ml, range: 518-1864 ng/ml; conventional: 431 ng/ml, range: 98-888 ng/ml; P<0.0001) and it was reached faster (median time of peak concentration: 1.6 hr vs. 2.9 hr, range: 1.0-3.0 hr vs. 1.9-4.0 hr; P=0.0009). The absorption lasted on the average 19% longer after the conventional formulation. The area under the concentration versus time curve (AUC) was larger after the microemulsion formulation in all but one patient (P=0.001) by a mean factor of 1.80 (range: 0.72-3.04). The trough CsA level after the microemulsion formulation was more closely related to peak concentration (r2=0.86 vs. 0.45) and AUC (r2=0.84 vs. 0.47); thus, therapeutic drug monitoring may be more useful. After 6 months on the new formulation, the results for the whole group were similar, but in five children the AUC was comparable to the AUC obtained with the conventional formulation. No rejections occurred, and the liver and kidney functions remained unchanged. A 1:1 conversion can be safely performed in children, based on a 6-month follow-up. However, the total drug exposure changes in significant ways, which, on a long-term basis, may improve the immunosuppression in an underimmunosuppressed patient, but may increase the risk for dose-related adverse effects in others.

Effect of age on the fulfilment of the IHS criteria for migraine in children at a headache clinic

In a headache clinic, 247 children suffering from severe recurrent headaches were studied in relation to the IHS criteria for migraine. Of the 247, 163 had migrainous headache, with 100 (67.5%) of these having migraine in accordance with the IHS criteria. The remaining 53 (32.5%) had headache attacks fulfilling all but one of the IHS criteria. Coverage of the IHS criteria for migraine was 93%. Symptoms of unilateral headache, aggravation by physical activity, and nausea showed the greatest differences in frequency between those with migraine and those with probable migraine. All children with aura fulfilled criteria for migraine. Children with migraine with aura (11.8, 95% CI: 11.0-12.6 years) were older than those without aura (10.1, 9.4-10.8 years; p = 0.001). Children with pulsating headache were slightly older than children without pulsating headache. No differences in age were detected with other IHS criteria.

Neonatal Candida parapsilosis outbreak with a high case fatality rate

A Candida parapsilosis outbreak of 58 cases in a neonatal intensive care unit lasted for 55 months. Patients infected by or colonized with C. parapsilosis were mainly very low birth weight infants (birth weight < 1500 g). Their mean birth weight was 817 g and their mean gestational age was 28 weeks. Statistical analysis including logistic regression confirmed that prematurity was the main risk factor. The analysis also suggested that C. parapsilosis infection (or colonization) was associated with a poor prognosis. In infants with gestational age < 29 weeks the risk for death in C. parapsilosis-infected patients was 16-fold greater than in those with no C. parapsilosis infection. The case fatality rate of C. parapsilosis patients was higher than that of the controls (9 of 23 vs. 1 of 40; P < 0.0001). The outbreak was most likely a result of cross-infection because C. parapsilosis could be isolated only from the patients and from the hands of four nurses immediately after they had cared for a colonized patient. Cessation of the outbreak was temporally associated with long term parenteral fluconazole (6 mg/kg/day) prophylaxis.

Flunarizine of limited value in children with intractable epilepsy

Fourteen ambulatory children and adolescents with intractable epilepsy were studied in an open phase II study to investigate the pharmacokinetics and pharmacodynamics of flunarizine as an add-on treatment. Flunarizine was given in increasing doses starting with 0.1-0.3 mg/kg/day until effect was observed or a steady-state plasma concentration of 50-60 ng/ml was reached. Treatment was continued for 3 months at steady state. Pharmacokinetics were determined during the immediate posttreatment period. Positive antiepileptic effect (> or = 50% reduction in seizure frequency) was observed in 4 of 14 patients (29%; 95% CI: 52-5). Independently of antiepileptic effect, 10 of 14 parents (71.4%; 95% CI: 95-48) observed positive cognitive effects. In all patients treatment was withdrawn due to either lack of effect or weight gain. Flunarizine was rapidly absorbed; mean time of peak concentration (Tmax) was 2.7 hours (range: 1-8). The mean terminal half-life was 23.2 days (range: 7-48), the total plasma clearance of flunarizine per fraction of the dose absorbed (CLp/F) was 0.28 ml/min/kg (range: 0.07-042), and the volume of distribution of flunarizine per fraction of the dose absorbed (Vd/F) was 187 L/kg (range: 99-348). We conclude that flunarizine (0.1-0.3 mg/kg/day) seems to be of limited antiepileptic value in children with intractable epilepsy. The pharmacokinetic profile of flunarizine complicates its clinical use.

Maternal drug treatment and human milk banking

We studied prospectively during one year temporary drug use by mothers donating breast milk to assess the problem of drug treatment of donors. Sixty-four of the 284 mothers (22.5%) had to abstain from donating due to medication. The indication was infection in 50/56 treatments (89.3%). Antimicrobial agents were prescribed 44/52 times (84.6%). The channelling of milk from mothers in early phases of lactation to premature and newborn infants was identified as a special risk situation, if mothers on medication are not excluded. The limited number of such donors leads to use of milk unpooled or pooled to small volumes with increased risk for adverse effects to babies as a consequence. We recommend a wash-out period of 5 half-lives of the drug after the last ingested dose. For the majority of drugs in this study, with some important exceptions, a wash-out period of 1 day was sufficient.

Pharmacokinetics of fluconazole in very low birth weight infants during the first two weeks of life

OBJECTIVE

To find a dose of fluconazole for very low birth weight infants during an outbreak of Candida parapsilosis.

METHODS

Twelve premature infants (mean gestational age, 27.4 weeks; mean birth weight, 912 gm) receiving fluconazole prophylactically from the first day of life were enrolled in an open phase I-II pharmacokinetics, safety, and tolerance trial. Up to 5 doses of 6 mg/kg were administered intravenously every 72 hours during the first 2 weeks of life. Pharmacokinetic characteristics of fluconazole were determined after the first, third, and fifth doses.

RESULTS

The mean peak and trough concentrations after the 3 doses were 5.5 and 2.6 micrograms/ml, 12.8 and 4.3 micrograms/ml, and 10.0 and 2.9 micrograms/ml (p = 0.0002 and p = 0.07), respectively. The mean fluconazole half-lives were 88.6 hours (n = 7), 67.5 hours (n = 9), and 55.2 hours (n = 4; p = 0.3). The mean total clearance corrected for weight (CL/kg) was 0.18 ml/min/kg (n = 7), 0.33 ml/min/kg (n = 7), and 0.52 ml/min/kg (n = 4; p = 0.02), and the mean volume of distribution 1.18 L/kg (n = 7), 1.84 L/kg (n = 7), and 2.25 L/kg (n = 4; p = 0.05). Weight-corrected clearance increased with postnatal age (r = 0.61; p = 0.007).

CONCLUSIONS

With the used fluconazole dose (6 mg/kg every 3 days), the mean serum peak and trough concentrations increased during the first week but decreased during the second week. After the first week we suggest a dose of 6 mg/kg every 2 days, or even daily.

Medical charcoal for a child's poisoning at home: availability and success of administration in Finland

In a prospective study, 174 families were interviewed over the telephone to find out whether the treatment of their child's poisoning with medical charcoal was successfully completed. The majority (103; 59.2%) of the families had no charcoal at home. The mean delay in administration for those who had to obtain charcoal was 41.6 min; significantly longer than the 24.5 min taken for those who had charcoal at home (P < 0.001). The treatment succeeded in all but five of the 102 patients given charcoal at home. Thus for mild poisoning in young children, the administration of activated charcoal at home, under the guidance of a Poison Information Centre, could be a rapid and safe first-aid treatment. Presently the widespread unavailability of charcoal in the home in Finland causes an unnecessary delay in treatment that could be of clinical importance.

Inositol supplementation in premature infants with respiratory distress syndrome

BACKGROUND

Inositol influences cellular function and organ maturation. Feeding premature infants inositol-rich breast milk increases their serum inositol concentrations. Whether inositol supplementation benefits infants receiving fluids for parenteral nutrition, which are inositol-free, is not known.

METHODS

We carried out a placebo-controlled, randomized, double-blind trial to determine the effects of administering inositol (80 mg per kilogram of body weight per day) during the first five days of life to 221 infants with respiratory distress syndrome who were receiving parenteral nutrition (gestational age, 24 to 32 weeks; birth weight, less than 2000 g). All the infants were treated with mechanical ventilation and some with surfactant as well. The primary end point was survival at 28 days without bronchopulmonary dysplasia.

RESULTS

The 114 patients given inositol had significantly lower mean requirements for inspiratory oxygen (P less than 0.01) and mean airway pressure (P less than 0.05) from the 12th through the 144th hour of life than did the 107 infants given placebo. Eighty-one infants given inositol and 51 given placebo survived without bronchopulmonary dysplasia (71 vs. 55 percent; P = 0.005). In the 65 infants given surfactant, however, inositol had no effect on the degree of respiratory failure. Thirteen infants given inositol and 21 given placebo had retinopathy of prematurity (13 vs. 26 percent; P = 0.022); none of the infants given inositol had stage 4 disease, whereas 7 of those given placebo did (0 vs. 9 percent; P = 0.012). Among the infants given placebo, those who had poor outcomes (death, bronchopulmonary dysplasia, or stage 4 retinopathy of prematurity) had lower serum inositol concentrations during days 2 through 7 than those who had good outcomes (P less than 0.01).

CONCLUSIONS

The administration of inositol to premature infants with respiratory distress syndrome who are receiving parenteral nutrition during the first week of life is associated with increased survival without bronchopulmonary dysplasia and with a decreased incidence of retinopathy of prematurity.

Evidence for pre-hepatic metabolism of oral cyclosporine in children

1. The pharmacokinetics of cyclosporine were investigated before renal transplantation in 20 children aged 1.1 to 16.8 years. Cyclosporine was given as a single oral dose (10 mg kg-1) or as a 4 h i.v. infusion (3 mg kg-1). 2. The blood drug concentration was measured by both specific and nonspecific monoclonal radioimmunoassays. 3. The mean oral availability of cyclosporine was 20.6% (range 10.8-34.1%). 4. The mean ratio of AUCs measured by nonspecific and specific r.i.a. was 1.96 (range 1.4-2.7) after oral administration and 1.43 (range 1.1-2.0) after i.v. administration. The mean difference between the ratios was 38.5% (P = 0.0001). The ratio of AUCnonspecific to AUCspecific was inversely related to blood drug clearance (r = 0.57; P = 0.009). 5. The findings are suggestive of presystemic, pre-hepatic metabolism of cyclosporine which could contribute to the low, and highly variable bioavailability of this drug.

Accidental astemizole overdose in young children

6 cases of accidental astemizole poisoning in children have been reported to the Finnish Poison Information Center. The children were aged 1 year 7 months to 3 years 4 months and had taken doses of 2.5 to 16.7 mg/kg, at least twelve times that recommended. In 2 children the overdose was verified by measurement of drug concentrations. Despite measures to prevent drug absorption prolonged QTc-interval, a sign of cardiac toxicity, was found in all 5 children on whom an electrocardiogram was available for analysis, and severe ventricular arrhythmias developed in 1. Young children with accidental astemizole overdose should be carefully monitored in hospital. Similar precautions may be justified in cases of overdose with other selective H1-histamine receptor antagonists.

Pharmacokinetically determined cyclosporine dosage in young children

To account for the individual variability in cyclosporine pharmacokinetics and the non-existence of dosing recommendations in young children, we studied the pharmacokinetics of cyclosporine before renal transplantation in ten children aged 1.1-2.5 years, to determine the appropriate individual dose. Our aim was to reach a steady-state cyclosporine blood level of 200-300 micrograms/l, 8 h after a dose in the first days after renal transplantation. Cyclosporine was given as a single oral dose (10 mg/kg) or as a 4-h i.v. infusion (3 mg/kg), and the blood concentration was determined for 24 h by a specific monoclonal radioimmunoassay. The mean terminal cyclosporine half-life (t1/2) was 9.3 h (range 2.8-20.4), blood clearance 10.8 ml/min per kilogram (range 6.8-22.7) and volume of distribution 2.8 l/kg (range 1.4-4.7). The bioavailability of oral cyclosporine was low; the mean amount absorbed was 21.8% of the administered dose (range 11-35). The mean calculated dose needed to attain the intended predose blood cyclosporine level of 200-300 micrograms/l at steady-state was 5 mg/kg per day for i.v. and 21 mg/kg per day for oral administration. In view of the short t1/2, we used three doses/day. The validity of the predicted doses is shown by the mean cyclosporine doses used during the first 10 days after transplantation, which were 93.5% of the calculated oral and 96.6% of the calculated i.v. doses. The observed mean cyclosporine concentration during the same period was 196 micrograms/l.

Surfactant proteins in the diagnosis of fetal lung maturity. II. The 35 kd protein and phospholipids in complicated pregnancy

The major surfactant protein with a molecular weight of 35 kd and also saturated phosphatidylcholine and phosphatidylglycerol were analyzed in specimens of amniotic fluid; 68 were from cases of maternal diabetes, 41 from preeclampsia or maternal hypertension, 26 from premature rupture of the fetal membranes, and 45 from normal pregnancies. The relationship between the individual surfactant components was studied after covariance adjustment for the length of gestation. In severe early-onset preeclampsia, the 35 kd surfactant protein/saturated phosphatidylcholine ratio was significantly higher than in the other pregnancies. In diabetic pregnancies (classes B to D without preeclampsia), the phosphatidylglycerol/saturated phosphatidylcholine ratio was lower than in the other pregnancies. Isolated surfactant complex showed similar abnormalities. In severe early-onset preeclampsia and insulin-dependent diabetes without vascular disease, the phosphatidylglycerol/saturated phosphatidylcholine ratio correlated negatively with fetal growth. In four samples of amniotic fluids from cases of severe early-onset preeclampsia, the 35 kd protein falsely predicted lung maturity. All had abnormally high 35 kd protein/saturated phosphatidylcholine ratios (greater than 2 SD of controls). According to the present results, the 35 kd protein may give a false mature test result in severe preeclampsia.

Changes in trimethoprim pharmacokinetics after the newborn period

The pharmacokinetics of trimethoprim administered orally or intravenously were investigated in six infants aged 1.7 months to 1.1 years. In these infants trimethoprim had a mean half life of 4.6 hours; this was comparable with the values found in young and school age children (3.8 and 5.4 hours respectively) and about a quarter of the half life in newborns. The volume of distribution (1.5 l/kg) was smaller than in newborns but larger than in young or school age children (0.9 and 1.1 l/kg respectively). The plasma clearance in these infants (3-3 ml/min/kg) was slightly larger than in newborns or in either group of older children (2.9 and 2.4 ml/min/kg respectively). Thus the most dramatic changes in trimethoprim pharmacokinetics seem to occur during the first two months of life. A reduced daily dose of trimethoprim is necessary during the first two months only. An increased daily dose, by addition of a third dose each day, is recommended from two months.

Trimethoprim in the treatment of acute urinary tract infections in children

In the first study to assess the effect of trimethoprim in the treatment of acute urinary tract infections in children, we compared it with sulphisoxazole. Eighteen girls, mean age 5.3 years, were treated with trimethoprim 6 mg/kg/day. Seventeen girls, mean age 5.0 years, treated with sulphisoxazole 150-200 mg/kg/day for 10 days served as controls. All infections were cured. Three patients in each group had reinfections during the 6 months of follow-up. In each group, one of the reinfections occurred within 2 weeks after the end of the treatment. One patient developed a rash from sulphisoxazole and so required drug change. No other adverse effects were observed. We conclude that trimethoprim is as effective as sulphisoxazole in the treatment of simple acute urinary tract infections of children and recommend it, in the dosage used, as an alternative first-choice drug, especially for patients who have had side effects from sulphonamides or nitrofurantoin.

Trimethoprim pharmacokinetics in children with renal insufficiency

We studied the pharmacokinetics of trimethoprim in 14 children (two neonates) with renal insufficiency. They were 1 week to 16.4 years old and had glomerular filtration rates (GFR) between 10.8 to 72.3 ml/min/1.73 m2. The half-life (t1/2) of trimethoprim was inversely related to the GFR. The relation followed a power curve (correlation of t1/2 with GFR: r = -0.86; P less than 0.001). The slower elimination rate was mainly the result of lowered renal clearance of trimethoprim. The volume of distribution (Varea) was, in most patients, in the upper normal range for children. In some of the patients, chiefly infants with severe renal insufficiency, the Varea was larger than normal. In some individuals the pharmacokinetics of trimethoprim deviated from that to be expected from the GRF. We recommend reduced daily doses of trimethoprim if the GFR is less than 30 ml/min/1.73 m2. The reduction should be proportional to the reduction in GFR and primarily take the form of a prolonged dose interval.

Inositol supplementation in respiratory distress syndrome: relationship between serum concentration, renal excretion, and lung effluent phospholipids

Inositol or placebo was given to 48 small preterm infants with respiratory distress syndrome (mean birth weight 1365 g, gestational age 30.1 weeks) between 48 hours and 10 days of age. The dose of inositol, 40 mg/kg every 6 hours, was at least as high as amounts received in full preterm human milk feedings. Serum inositol concentration increased between days 2 and 3 from a mean of 566 mumol/L to 823 mumol/L in the infants given supplement and fell from 451 mumol/L to 292 mumol/L in the controls. On day 16, serum inositol values remained higher in the infants given supplement than in those given placebo (mean 334 mumol/L vs 146 mumol/L, P = 0.014). The infants who developed bronchopulmonary dysplasia had significantly higher renal inositol clearance, lower inositol intake, and lower serum inositol concentrations. Inositol supplementation increased the saturated phosphatidylcholine/sphingomyelin ratio in tracheal aspirates. According to these results, supplementation with inositol in preterm infants leads to a rise in serum inositol concentration and improvement in the surfactant phospholipids. Inositol deserves further study as a dietary supplement for immature preterm infants who do not receive full human milk feeds.

Age differences in trimethoprim pharmacokinetics: need for revised dosing in children?

The pharmacokinetics of trimethoprim was studied in children (nine girls 1.05 to 3.57 years old and nine girls 7.55 to 9.70 years old) with urinary tract infections and 12 healthy adults (27.07 to 44.62 years old) to investigate any age-related changes. Serum and urine concentrations were measured during 24 hours. The groups did not differ in the time or the height of the peak serum concentration. Thereafter the children had lower serum concentrations. They had a shorter elimination half-life (means: 1 to 3 years, 3.7 hours; 8 to 10 years, 5.4 hours; adults, 11.2 hours), because of the smaller volume of distribution (0.86 l/kg; 1.08 l/kg; 1.31 l/kg) and higher total clearance (2.8 ml/min/kg; 2.4 ml/min/kg; 1.4 ml/min/kg). The higher clearance in children was mainly nonrenal (metabolism). Calculation of the pharmacokinetic variables per unit of body surface area modified the age differences considerably. Compared with present dosage recommendations, trimethoprim in larger daily doses per kilogram of body weight for the children is suggested. The daily dose should be increased primarily by shortening the dose interval.

Determination of trimethoprim in pediatric samples by high-performance liquid chromatography

We describe and evaluate modifications to a known high-performance liquid chromatography assay of trimethoprim. The sensitivity, specificity and wide range of linearity (0.11-690 mumol/l) of this method make it suitable for analysing samples with large variations in volume and concentration. We have used it to study the pharmacokinetics of trimethoprim in children, including newborns. Automated injection is a useful option if the sample volume is not limited. The recovery (at 3.44 mumol/l) of the method was 99.8% with a coefficient of variation of 6.8% for manually injected samples. The corresponding results for automated injection were 97.9% and 12.8%.

Food and guar decrease absorption of trimethoprim

Absorption of trimethoprim suspension 3 mg/kg has been studied in 12 healthy adult volunteers when given alone, with food or with food and guar, using a randomised Latin-squares study design. Serum and urine trimethoprim concentrations were followed for 24 h. The mean peak serum concentration was higher when fasting subjects were treated (mean: 2.35, 1.84 and 1.97 micrograms/ml for the fasting, food and food + guar groups, respectively; ANOVA p less than 0.001 for the difference between fasting and non-fasting values). The times of the peak serum concentrations did not differ. Food ingestion decreased the area under the curve by 22.2%, as did food + guar. For maximal efficacy trimethoprim should be administered between meals.