药物的作用可分为治疗作用和副作用；副作用是无助于治疗效果的行为。有些副作用是中性的；其他经历过的不良或不愉快则被记录为不良影响。有些药物作用对某些疾病有治疗作用，但对另一些疾病则不利；或急性疾病期间的治疗和维持治疗期间的不良反应。例如，当三环类抗抑郁药用于治疗抑郁症时，抗胆碱能作用可能是不利的，但当该药物用于治疗腹泻性肠易激综合征时，抗胆碱能作用可能是治疗性的。在临床实践中，可以利用药物的副作用或不良反应来控制麻烦的症状。例如，低剂量曲唑酮的镇静作用可能对某些失眠患者有用。在此背景下，研究人员检验了与奥氮平和米氮平相关的食欲和体重增加是否可以有效治疗与癌症和癌症化疗相关的厌食症和恶病质。该主题很重要，因为 30%-50% 的癌症患者可能存在恶病质（晚期癌症患者的患病率较高），而且恶病质的存在与疾病进展和死亡的较高风险相关。许多随机对照试验（RCT）检查了药物干预措施，例如孕激素、皮质类固醇、阿拉莫林和医用大麻治疗癌症相关恶病质；大多数结果令人失望。最近的一项随机对照试验发现，奥氮平（2.5 毫克/天，持续 12 周）可改善接受化疗的局部晚期或转移性癌症患者的食欲、体重、其他营养参数和生活质量。然而，另一项随机对照试验发现，米氮平（30 毫克/天，持续 8 周）对癌症和厌食症患者没有带来营养或人体测量方面的益处。结论是奥氮平而非米氮平值得在患有厌食症和恶病质的癌症患者中进行进一步研究。© 版权所有 2024 Physicians Postgraduate Press, Inc.

Drugs have actions that may be classified as therapeutic effects and side effects; side effects are actions that do not contribute to therapeutic benefit. Some side effects are neutral; others, experienced as undesirable or unpleasant, are recorded as adverse effects. Some drug actions are therapeutic for some disorders and adverse for others; or therapeutic during acute illness and adverse during maintenance treatment. As an example, anticholinergic action may be adverse when a tricyclic antidepressant is used to treat depression but therapeutic when the drug is used to treat irritable bowel syndrome with diarrhea. In clinical practice, side or adverse effects of a drug may be leveraged to manage troublesome symptoms. As an example, the sedative effect of a low dose of trazodone may be useful for some patients with insomnia. With this background, studies have examined whether the increase in appetite and weight associated with olanzapine and mirtazapine may be effective against anorexia and cachexia associated with cancer and cancer chemotherapy. The subject is important because cachexia may be present in 30%-50% of patients with cancer (with higher prevalence in patients with more advanced cancer) and because the presence of cachexia is associated with a higher risk of disease progression and mortality. Many randomized controlled trials (RCTs) have examined pharmacologic interventions such as progestins, corticosteroids, anamorelin, and medical cannabis for cancer related cachexia; most results have been disappointing. A recent RCT found that olanzapine (2.5 mg/d for 12 weeks) improved appetite, weight, other nutritional parameters, and quality of life in patients with locally advanced or metastatic cancer treated with chemotherapy. Another RCT, however, found that mirtazapine (30 mg/d for 8 weeks) brought no nutritional or anthropometric gain in patients with cancer and anorexia. It is concluded that olanzapine but not mirtazapine merits further investigation in patients with cancer who have anorexia and cachexia.© Copyright 2024 Physicians Postgraduate Press, Inc.