Relación entre niveles de carbamazepina en saliva y plasma: Estudio piloto / Saliva and plasma levels of carbamazepine have a poor correlation: a pilot study

Abstract: Carbamazepine is one of the most commonly used anticonvulsants for the treatment of epilepsy and its plasma concentrations must be monitored periodically to obtain a useful and safe clinical effect. There is not a good relationship between the dose of the carbamazepine and their effects in humans, but the effects of this drug have been well correlated with its plasma levels. Aim: To measure the correlation between plasma and saliva levels of carbamazepine in children with epilepsy. Material and Methods: Saliva and plasma levels of carbamazepine were measured by using instrumental planar chromatography in 11 epileptic children aged 8 to 15 years treated with the drug for at least six months. Results: The mean saliva/plasma ratio was 0.18±0.05 and the mean of carbamazepine concentration in saliva, expressed as a percentage of concentrations in plasma, was 17.97±5.40. There was a poor linear correlation (r =0.37) between the concentrations of carbamazepine in both fluids. Conclusions: In this group of epileptic children the correlation between saliva and plasma carbamazepine levels was weak.

Características del uso de Sildenafil en una muestra de pacientes a nivel de farmacias comunitarias de Concepción, Chile / Features of subjects purchasing Sildenafil at community pharmacies in Concepción, Chile

Background: Erectile dysfunction is a public health problem. Millions of men worldwide experience this condition, affecting their quality of life. Sildenafil, a phosphodiesterase type 5 inhibitor, is the treatment of choice for erectile dysfunction. Aim: To study the characteristics of Sildenafil use among costumers of community pharmacies in Concepcion Chile. Material and methods: A structured interview about Sildenafil use was applied to subjects purchasing the drug in community pharmacies and that consented to participate. Results: One hundred thirty eight males were studied. Forty six percent of patients were fifty years old or older. Most (47.1%) used Sildenafil for one year or more and 60.5% had no adverse events. Among those experiencing side effects, headache was experienced by 38.9%, flushing by 16.6% and gastrointestinal effects by 16.7%. Ninety percent of patients had a good evaluation of the drug in terms of benefits and tolerance. Thirty two percent of the subjects, had diseases associated to erectile dysfunction. Among these, 45% had diabetes mellitus, 29.5% had hypertension, and 18.2% had prostatic diseases. In 54% of cases, the drug was prescribed by a physician. Twenty two percent of patients experienced changes in the effect of the drug when it was simultaneously used with other drugs or meals. Thirty four percent of patients used other drugs. Among these, 43.3% were using antihypertensives, and 26.7% were using antidiabetic drugs. Conclusions: Considering the elevated age and the number of associated disease of patients using Sildenafil, the use of the drug under medical prescription must be emphasized to avoid untoward effects.

Estudio de la estabilidad química de comprimidos de ácido acetilsalicílico mediante un control de estanterías en farmacias de Concepción, Chile / Chemical stability of acetylsalicylic acid tablets during storage in pharmacies at Concepción, Chile

Background: The chemical stability of a pharmaceutical product depends, among other factors, on environmental factors during transport, storage and manipulation of the product. Aim: To study the chemical stability of acetylsalicylic acid (AAS) tablets during ten months of storage in five pharmacies of Concepci-n, Chile. Material and methods: Tablets were randomly collected at the beginning of the study and at the third, sixth and tenth month. Quantitative analyses of AAS tablets was carried out by instrumental thin layer chromatography (HPTLC). Results: AAS in tablets was between 99 and 109 percent at the beginning of the study, between 76 and 110 percent at three months, between 71 percent and 112 percent at six months and between 86 and 110 percent at ten months of storage. Conclusions: There was a progressive decrease in the content of acetylsalicylic acid in tables during storage, but it remained between the limits accepted by the United States Pharmacopoeia (USP) (90-110 percent)