RESUMO

Many foods interact with drugs and may cause changes in the pharmacological effects of the co-administered therapeutic agent. The enzyme CYP3A4, which belongs to the cytochrome P450 enzyme complex, is responsible for the metabolism of most drugs currently on the market and is involved in many drug interactions. Hence, the interaction of this enzyme with juices of some fruits, such as grapefruit, can affect the pharmacokinetics of various drugs. However, native fruits from the Amazon region have not yet been the target of this type of research. We determined total polyphenols and flavonoids of the Amazonian fruits açaí (Euterpe precatoria), buriti (Mauritia flexuosa), camu-camu (Myrciaria dubia), cubiu (Solanum sessiliflorum), cupuaçu (Theobroma grandiflorum), jenipapo (Genipa americana), and taperebá (Spondias mombin) and evaluated the effects of each fruit juice on CYP3A4 activity, using the star fruit (Averrhoa carambola) juice as positive control. Açaí juice presented the highest content of total polyphenols and flavonoids (102.6 ± 7.2 µg gallic acid equivalent (GAE) per mL and 7.2 ± 0.6 µg quercetin equivalent (QE) per mL, respectively). All juices were able to inhibit the activity of CYP3A4. There was no residual activity of the drug-metabolizing enzyme for açai, buriti, cubiu, camu-camu, and taperebá juice, while for cupuaçu, jenipapo and the positive control, the residual activity was 44.3, 54.3 and 20.2%, respectively. Additional studies should identify the phytocompound(s) responsible for this inhibition activity, to clarify the mechanisms involved in this phenomenon.(AU)

Muitos alimentos interagem com medicamentos e podem causar alterações nos efeitos farmacológicos do agente terapêutico coadministrado. A enzima CYP3A4, que pertence ao complexo enzimático do citocromo P450, é responsável pelo metabolismo da maioria dos medicamentos atualmente no mercado e está envolvida em muitas interações medicamentosas. Assim, a interação dessa enzima com sucos de algumas frutas, como a toranja, pode afetar a farmacocinética de vários medicamentos. No entanto, frutas nativas da região amazônica ainda não foram alvo desse tipo de pesquisa. Determinamos polifenóis e flavonoides totais dos frutos amazônicos de açaí (Euterpe precatoria), buriti (Mauritia flexuosa), camu-camu (Myrciaria dubia), cubiu (Solanum sessiliflorum), cupuaçu (Theobroma grandiflorum), jenipapo (Genipa americana) e taperebá (Spondias mombin) e avaliamos os efeitos de cada suco de fruta sobre a atividade de CYP3A4, utilizando o suco de carambola (Averrhoa carambola) como controle positivo. O suco de açaí apresentou o maior teor de polifenóis totais e flavonóides (102,6 ± 7,2 µg equivalente de ácido gálico (GAE) por mL e 7,2 ± 0,6 µg equivalente de quercetina (QE) por mL, respectivamente). Todos os sucos foram capazes de inibir a atividade de CYP3A4. Não houve atividade residual da enzima metabolizadora de fármacos para os sucos de açaí, buriti, cubiu, camu-camu e taperebá, enquanto para cupuaçu, jenipapo e o controle positivo, a atividade residual foi de 44,3, 54,3 e 20,2%, respectivamente. Estudos adicionais devem identificar o(s) fitocomposto(s) responsável(is) por esta atividade de inibição, para esclarecer os mecanismos envolvidos neste fenômeno.(AU)

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RESUMO

Topiramate (TPM) is a second-generation antiepileptic drug (AED), acting on drug-resistant epilepsy. The aim of the study was to evaluate the influence of the dose, use of other AEDs on TPM plasma concentration (Cp ), and frequency of epileptic seizures. A cross-sectional analytical study was developed with patients aged 18-60 years, for diagnosis of drug-resistant epilepsy, using TPM in monotherapy or associated with other AEDs. The following variables were analyzed: age, frequency of epileptic seizures, pharmacotherapeutic regimen with its respective doses, adherence to medication treatment, and adverse events score. Thirty-seven patients were included, 83.8% of the patients presented Cp below the therapeutic range. Multiple linear regression estimated that the increase of 1.0 mg/kg/d promoted an increase of 0.68 µg/mL in TPMCp , while the use of inducers predicted a reduction of 2.97 µg/mL (P < .001). Multiple Poisson regression predicts that an increase of 1.0 µg/mL in TPMCp decreased the patient's chance of presenting seizures, and patients using AED inducers were about ten times more likely to present seizures than those who do not use (P < .001). In addition, for patients using AED inducers with Cp below the therapeutic range, the mean number of seizures per month was greater than those with Cp within the therapeutic range. The prescribed dose and the use of AED inducers influence Cp of TPM, likewise the low Cp of first-line AEDs and of the adjuvant in the treatment, TPM, as well as low TPM dose seem to affect the control of epileptic seizures.

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