Phenytoin serum concentration monitoring during pregnancy and puerperium in Mexican epileptic women.

Phenytoin serum concentrations were evaluated in 88 epileptic women at different stages of pregnancy and 40 women during postnatal periods. In addition, concentrations were determined from the umbilical cords of 27 neonates. On average, the dose of phenytoin was increased by 130 +/- 54 mg in 67% of the patients in order to control seizures. In 76% of the women during pregnancy and 95% in the postnatal periods, dose adjustment was achieved for the control of the seizures. Therapeutic clinical concentrations ( < 9.9 micrograms/ml) were found in 64% of the patients, with an average of 7.2 +/- 1.8 micrograms/ml during pregnancy and 6.2 +/- 2 micrograms/ml in 90% of the women during the postnatal period. The average phenytoin concentration reached with doses of 100, 200, 300, 400 and 500 mg were 3.3, 5.7, 8.4, 10.8, and 14.1 microliters/ml, respectively, without statistically significant differences among the pharmacokinetic parameters measured during pregnancy, between pregnancy and the postnatal period. The proportion between fetal and maternal phenytoin concentration was 0.37 +/- 0.28. Hydantoin fetal syndrome was seen in 8% of the neonates, without a statistically significant difference among patients with or without seizures. No relation was found between the concentration of phenytoin during pregnancy and the hydantoin fetal syndrome. The study shows that low concentrations of phenytoin can control seizures during pregnancy and the postnatal period and the need to relate serum phenytoin concentrations with the clinical state of pregnant women who suffer seizures.

[Nifedipine in gynecology and obstetrics]. / Nifedipina en ginecología y obstetricia.

Nifedipine has both vasodilator and relaxant actions in arterial smooth muscle and other tissues, like uterus. The goal of this review is describe the potential uses of this calcium antagonist in two clinical features in pregnancy. First, in premature labor, nifedipine is an appropriate alternative related with beta-mimetic or prostaglandin synthetase inhibitors agents, with good tocolytic properties and safe for both mother and baby. Second, in the treatment of hypertension in pregnancy or preeclampsia, where, according literature, nifedipine would be a valuable therapeutic gun. It is exposed the nifedipine advantages and disadvantages in pregnancy found by the authors from the reports reviewed here. It is analyzed the ethics of nifedipine use in pregnancy. Moreover, it is pointed out the nifedipine clinical usefulness in the treatment of primary dysmenorrhea and it is analyzed some nifedipine hemodynamic aspects on uterine blood flow.

[Post-dosage loading concentrations of theophylline and pharmacokinetic study after the fifth maintenance dosage in premature newborns with apnea]. / Concentraciones de teofilina postdosis de impregnación y estudio farmacocinético en la quinta dosis de mantenimiento en recién nacidos pretérmino con apneas.

From a group of 50 premature newborns with central and mixed apnea, 34 received a loading dose of 4.3 mg/kg intravenous theophylline (group I) and 16 received 6 mg/kg orally (group II); the maintenance dose was 0.86 and 1 mg/kg every eight hours, respectively. Mean maximum serum concentrations after the loading dose were 5.8 +/- 2.3 mcg/mL in 25 newborns from group I, and 6.6 +/- 1,3 mcg/mL in 8 newborns from group II (P less than 0.20). Mean maximum concentration after the fifth maintenance dose was 7.5 +/- 1.7 mcg/mL in 26 newborns from group I, and 5.8 +/- 1.4 mcg/mL in 16 newborns from group II (P = 0.001); mean minimum concentration was 5.3 +/- 1.6 mcg/mL and 4.5 +/- 1.4 mcg/mL, respectively (P greater than 0.10). Mean clearance was 30.21 +/- 11.03 and 27.1 +/- 7.7 mL/kg/h; mean apparent distribution volume was 0.5 +/- 0.25 and 0.76 +/- 0.32 L/kg; elimination rate constant was 0.049 +/- 0.04 and 0.040 +/- 0.03/h-1 for both groups respectively, with significant differences between groups only in the apparent distribution volume (P less than 0.001). Half-life time (T1/2) was from four to 118 hours. The study population was divided into three groups according to half-life time: those with a half-life time of lesser than 20 hours (47.6%); an intermediate half-life time of from 20 to 30 hours (23.8%); and a long half-life time of more than 31 hours (28.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Relation between dose, plasma concentration and therapeutic effect of theophylline in children with sleep apnea]. / Relación entre la dosis, concentración plasmática y efecto terapéutico de teofilina en niños con apnea del sueño.

The plasma concentration of theophylline was determined in twelve children with infantile sleep apnea (average age 48.5 days). The purpose of the study was to correlate concentrations with the dosages given, the therapeutic response and any adverse effects which could arise. In addition, other pharmacokinetic values were found, half-life (t 1/2) and clearance concentrations (Clss). The oral maintenance dose used was 4 mg/kg/24 h. The serum concentration of theophylline was determined by a homogeneous immunoassay enzyme technique (EMIT). A bad correlation was found (r = 0.45) between the oral dosage given and the plasma concentrations found. This was probably due to variations in the clearance of the drug. Yet, plasma concentrations fell between 3.0 and 12.6 micrograms/mL, enough to satisfactorily control apneic episodes in all the children included in the study without undesirable side-effects. Only one patient had some trouble in falling asleep and showed signs of irritability. The half-life was 13.30 +/- 7.46 hours and Clss was 36.64 +/- 12.98 mL/h/kg. In general, our results correlate with those reported in the literature. The accuracy of the pharmacokinetic parameters with two samples is reliable, therefore avoiding the use of multiple sampling in this group of children.

[Indications and contraindications for analgesics and antibiotics in pediatric dentistry]. / Indicaciones y contraindicaciones de analgésicos y antibióticos en odontología pediátrica.

A general overview upon most used products in odontopediatrics is presented; the factors which influence the determination of the adequate doses in children and some useful recommendations in dental clinical practice are described. The most prescribed products in pediatric odontology are summarized into two groups: a) benzodiazepine, for anxiety and lidocaine, aspirin and acetaminophen, dipirone and naproxen, for pain; and b) penicillin, erythromycin, for treatment of infections. Doses, pharmacologic effects, clinical indications, side effects and contraindications of the chemicals mentioned are described. Also, the article presents some of the aspects which justify the use, in our country, of certain medicaments prescribed in other nations reporting, the recommendations in order to prevent the use of other chemicals because of their lack of therapeutical advantages over the ones of first choice.