Efeitos determinados pela amitriptilina, administrada pela via subaracnóidea, sobre a medula e as meninges: estudo experimental em cães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação da participação de adrenoceptores α1 no efeito antinociceptivo da amitriptilina em um modelo de dor neuropática

Tricyclic antidepressants, such as amitriptyline, are inhibitors of serotonin and norepinephrine neuronal reuptake and this action has been implied in changes in pain threshold supporting its use to alleviate neuropathic pain. Although is known that 1 adrenoceptors participate in the antinociceptive effect of amitriptyline it is unclear which receptor subtype is the target for the increased synaptic levels of norepinephrine resultant from the inhibition of neuronal uptake. Paradoxically, several tricyclic antidepressants including amitriptyline also behave as antagonists of 1 adrenoceptors with different affinities for its subtypes: these drugs have 10 to 100-fold higher affinities for 1A than for 1B and 1D adrenoceptors. This work investigated the involvement of 1 adrenoceptors subtypes in the antinociceptive effect of the amitriptyline in a constriction of the sciatic nerve in rats by determining the effects of subtype selective 1 adrenoceptors antagonists. Fifteen days later, mechanical hyperalgesia was analyzed in a Randall-Selitto test. The 1A-selective antagonist RS100329 was the most potent antagonist of the contractions of the rat prostate, whereas the 1D-selective antagonist BMY 7378 (up to 100g/Kg) was unable to affect these contractions. The antagonist prazosin, BMY 7378 and 5-methyl urapidil inhibited the antinociceptive effect of the amitriptyline. However, the highly selective 1A adrenoceptor antagonist RS100329 was unable to affect the antinociception induced by amitriptyline. These results point out that 1B and/or 1D adrenoceptors, but not 1A, are involved in the antinociceptive effects of amitriptyline

Medicamentos inadequados para idosos na estratégia da saúde da família

The ageing process can change the pharmacodynamics and pharmacokinetics parameters. Therefore, some medications are considered potentially inappropriate (PIM) for the elderly people, since they can increase the likelihood of occurrence of adverse drug events. The objectives are to estimate the frequency of use of PIM in the elderly people, with potentially hazardous drug interactions (PHDI) and to evaluate the impact of pharmaceutical intervention (PI) for the prescription of safer therapeutic alternatives. A cross-sectional study was performed in a Health Family Strategy (region of Araraquara, SP), between January and February/2012. The medical records of patients aged ≥60 years, that use at least one drug, were consulted for identification of PIM, according to the Beers criteria. The MPI identified were classified considering the Anatomical Therapeutic Chemical Classification System (ATC) and the essentiality of the drug (safety, effectiveness, quality and cost parameters) The inclusion criteria were met by 358 elderly, being that 93 of them (26%) had taken at least one PIM. Of the 114 different drugs prescribed for elderly, ten were classified as PIM, of which four of them act on the central nervous system, four on cardiovascular system and two on the digestive tract. Seven MPI are essential medicines, belonging to national list of essential drugs (RENAME-2010). Fourteen drug interactions were identified, of which two are PHDI (fluoxetine/amitriptyline and digoxin/hydrochlorothiazide).After the PI, there was no change in medical prescriptions of patients with PIM use or with DI. Medical prescriptions of elderly attended in the Health Family Strategy show pharmacotherapeutic safety problems, of which may be responsible for health hazardous for this age group. Although the intervention carried out by letter had been ineffective for the adherence of doctors in prescribing safe alternatives, wide dissemination of the lists that contain PIM and PHDI is need, as well as the inclusion of safer equivalents in RENAME, in order to contribute for rational use of drugs.