Antipsychotics: Contraindications and Cautions
抗精神病药：禁忌和注意事项
Antipsychotic drugs are contraindicated in the presence of underlying diseases that could be exacerbated by the dopamine-blocking effects of these drugs. They are also contraindicated in the following conditions, which can be exacerbated by the drugs: central nervous system (CNS) depression, circulatory collapse, Parkinson disease, coronary disease, severe hypotension, bone marrow suppression, and blood dyscrasias. Prolongation of the QTc interval is a contraindication to the use of mesoridazine, thioridazine, and ziprasidone, all of which can further prolong the QTc interval, leading to increased risk of serious cardiac arrhythmias. Antipsychotics are contraindicated for use in elderly patients with dementia because this use is associated with an increased risk of cardiovascular events and death. In 2005, the U.S. Food and Drug Administration (FDA) issued a public health advisory regarding the use of antipsychotics after postmarketing studies showed that when these drugs were used to control behavioral symptoms of dementia in older adults, the patients being treated experienced increased cardiovascular events and death. None of these drugs is approved for this use, but it was common practice in many settings to use them, off-label, to establish behavioral control of patients with dementia. The manufacturers of all of these drugs sent out “Dear Health Care Provider” letters to remind health care providers that this is not an approved use and to alert them of the risk for death if they used the drug in this way. Antipsychotics now have a black-box warning on the prescribing information outlining this safety information and contraindication.
Caution should be used in the presence of medical conditions that could be exacerbated by the anticholinergic effects of the drugs, such as glaucoma, peptic ulcer, and urinary or intestinal obstruction. In addition, care should be taken in patients with seizure disorders because the threshold for seizures could be lowered; in patients with thyrotoxicosis because of the possibility of severe neurosensitivity; and in patients with active alcoholism because of potentiation of the CNS depression.
Other situations that warrant caution include myelography within the last 24 hours or scheduled within the next 48 hours because severe neuron reaction to the dye used in these tests can occur and pregnancy or lactation because of the potential of adverse effects on the fetus or neonate; antipsychotic agents should be used only if the benefit to the mother clearly outweighs the potential risk to the fetus or baby. Because children are more apt to develop dystonia from the drugs, which could confuse the diagnosis of Reye syndrome, caution should be used with children younger than 12 years of age who have a CNS infection or chickenpox. The use of antipsychotics may result in bone marrow suppression, leading to blood dyscrasias, so care should be taken with patients who are immunosuppressed and those who have cancer.
underlying diseases – 基础病
dopamine-blocking effects – 多巴胺阻滞效应
mesoridazine – n. 美索达嗪
thioridazine – n. 硫利达嗪
ziprasidone – n. 齐拉西酮
advisory – n. (情况)报告
postmarketing – a. 售后
off-label – a. 标签外使用的
thyrotoxicosis – n. 甲状腺毒症
neurosensitivity – n. 神经敏感性
potentiation – n. 增强，强化
warrant – v. 成为…的根据，使有（正当）理由
myelography – n. 脊髓造影
dystonia – n. 张力失常
dyscrasia – n. 体液不调，恶液质
1. A client is prescribed with sertraline (Zoloft). To guarantee a safe administration of the medication, a nurse would administer the dose:
A. As needed only for depressions.
B. Early in the morning.
C. Take on an empty stomach.
D. At bedtime. 2. The male client diagnosed with schizophrenia is prescribed ziprasidone. Which statement to the nurse indicates the client understands the medication teaching?
A. “I need to keep taking this medication even if I become impotent.”
B. “I should not go out in the sun without wearing protective clothing.”
C. “This medication may cause my breast size to increase.”
D. “I may have trouble sleeping when I take this medication.”
1. D. At bedtime.
Sertraline (Zoloft) is an antidepressant. It may be administered in the morning or evening, but giving it in the evening is more favored since drowsiness is one of the side effects. 2. D. “I may have trouble sleeping when I take this medication.”
Ziprasidone (Geodon), an atypical antipsychotic, is well tolerated, but the most common side effect is difficulty in sleeping, perhaps because of the histamine antagonist blockade effect of the drug. This comment indicates the client understands the teaching.
当前位置：
