Acompanhamento farmacoterapêutico de pacientes com câncer de pulmão, em tratamento no HCI/INCA

RESUMO

...Muitos pacientes com doenças que ameaçam a vida, como o câncer, não selimitam ao tratamento prescrito pelo médico assistente e, na esperança da cura, buscam tratamentos alternativos cujos resultados são de difícil avaliação (Beijnen e Schellens, 2004). No anseio da cura ou mesmo do alívio de sintomas, se automedicam por repetição de prescrições anteriores ou por indicação de parentes ou amigos (Arrais et al., 1997) e usam substâncias de efeito indeterminado como fitoterápicos e produtos naturais (Turolla e nascimento, 2006). Esse cenário, apesarde presumido, não pode ser avaliado precisamente, uma vez que freqüentemente não é relatado pelo paciente ao seu médico assistente (Rockwell et al., 2005).Assim, pouco se sabe sobre a prevalência de uso de produtos alternativos e do risco da ocorrência de reações adversas decorrentes de interações medicamentosas (Elmer et al., 2007). Na vigência da quimioterapia antineoplásica, devido à estreitamargem terapêutica, a possibilidade dessas associações cria um quadro maior de incertezas, pela possibilidade de potencialização de toxicidades, elevando-as a graus inaceitáveis (Oates, 2006; Rockwell et al., 2005).Dentro desse contexto, a intervenção do farmacêutico pode representarrecurso poderoso na identificação dessas interações (Weideman,1999; Batlle, 2002; ASPH, 1995; Ikeda et al., 2005, Chumney e Robinson, 2006), as quais pioram a qualidade de vida do paciente, interferem no tratamento e podem ser fatais (Mcleod, 1998). Em nosso estudo, o farmacêutico se colocou em contato direto com o paciente em tratamento quimioterápico antineoplásico, para identificação do uso de medicamentos prescritos e não prescritos, incluindo medicamentos alopáticos e fitoterápicos e de produtos naturais e para caracterização da ocorrência de reações adversas clinicamente significativas, buscando a proposição de uma prática quecontribua para melhoria da assistência ao paciente, com relação a prevenção emanejo das reações adversas.

ABSTRACT

Patients with lung cancer demand special care not only because of the symptoms and complications due to the progression of the disease, but also because of agerelated comorbidities, continuous use of drugs and use of non-authorized products for intended therapeutical purposes. Because of the narrow safety range of chemotherapy agents, these drug associations may lead to increased toxicities. The main objective of our study was to evaluate the safety of the chemotherapy treatment used for patients with lung cancer in HCI/INCA, in order to improve the quality of the oncologic care. We developed a methodology of pharmacotherapeutic follow-up in order to characterize the frequency and the severity of clinically significant adverse events and to identify the use of prescribed and non-prescribed products, including conventional drugs, phytotherapy and non-authorized therapeutical products. The strategy of pharmacotherapeutic follow-up was based on patient interviews, consults to the patient’s clinical records and laboratory exams and consults to the clinical staff, with no intervention on the definition of clinical conducts. We evaluated 62 patients who were treated exclusively with chemotherapy protocols combining cisplatin or carboplatin to etoposide. The patients had median age of 61years-old (95%CI 59-64), with previous history of tobbacco use (85%) and presence of comorbidities (61%), hypertension being the most frequent (40%). Most patients had advanced disease, with non-small cell lung cancer being predominant (84%) and adenocarcinoma the most frequent hystologic type (56%). Comparing the protocols with carboplatin or cisplatin, we found significant difference on the frequency of emesis, which was more frequent in the group treated with cisplatin, and thrombocitopenia, which was more frequent in the group treated with carboplatin. However, the protocols did not differ on the risk of severe toxicities (grades III or IV). Therefore, we evaluated the global risk of the chemotherapy treatment, regardless of the platinum agent used. We found increased relative risk of hematological toxicities (neutropenia, febrile neutropenia, anemia and thrombocitopenia), gastrointestinal toxicities (constipation, nausea, emesis, mucositis, abdominal pain and diarrhea) and dermatological toxicities (alopecia, itching e desquamation). There was also increased risk of severe toxicities (grades III or IV) for neutropenia (68%), febrile neutropenia (27%) and constipation (34%). The drugs used previously to the chemotherapy treatment included analgesics (42%), opioid analgesics (40%), anti-hypertensives (40%), antiulcer e antacids (39%). Non-prescribed drugs were reported by 24% of the patients, laxatives being the most frequently used (14%). During the chemotherapy treatment, there was a significant increase in the use of the following agents antiemetic (100%), propellant (64%), anti-ulcer and antacid drugs (43.5%), antimicrobial agents (39%), axatives (37%), opioid analgesics (21%) and anxyolitics (21%). We also found increase on the use of non-prescribed drugs (24%), laxatives presenting the higher increase (17%). Taken together, these results suggest that the pharmacological support to adverse events should be improved, particularly with relation to the revention of febrile neutropenia and to the prevention and treatment of constipation. The methodology developed here may contribute for implantation of the practice of pharmaceutical care in HCI/INCA.