We Must Judge Analgesic Effect of Analgesic Medicine
Author(s): Katsuhiro Toda
Analgesic medicine that does not provide analgesic effect in each patient is merely a toxic substance for the patient. The judgement of analgesic effect after analgesic medicine administration is the most basic of pharmacological treatment for pain. The judgment is classified into four categories: improvement, invariance, deterioration, and obscureness. If the patient's answer is ambiguous, it should be considered invariance. If the judgement is impossible because of ambiguous answer of the patient, we should discontinue the medicine or increase the dose to judge the analgesic effect. If it’s invariance or deterioration and the initial dose is maximum dose, we should switch to another medicine. If it’s invariance or deterioration and the initial dose is not maximum dose, we should increase the dose. If it’s improvement and patient satisfies the pain, the dose should be maintained. If it’s improvement and patient does not satisfy the pain, we have two options. If the initial dose is maximum dose, another medicine should be added. If the initial dose is not maximum dose, the dose should be maintained. The period from initiation of pharmacological treatment to judgement of analgesic effect varies depending on the medicine. In case of nonsteroidal antiinflammatory drugs or acetaminophen, the period is less than 1 week. If the initial dose of the medicine for neuropathic pain is maximum dose, the period is usually 4 weeks. If the initial dose of the medicine (such as amitriptyline) for neuropathic pain is not maximum dose, I increase daily dose every 1 week.