Contraindication, Adverse Effects, and Interaction of Barbiturates
巴比妥酸盐类药的禁忌、不良效应和药物相互作用
1. Contraindications and Cautions 禁忌与注意事项
Contraindications to barbiturates include allergy to any barbiturate and a previous history of addiction to sedative/ hypnotic drugs because the barbiturates are more addicting than most other anxiolytics. Other contraindications are latent or manifest porphyria, which may be exacerbated; marked hepatic impairment or nephritis, which may alter the metabolism and excretion of these drugs; and respiratory distress or severe respiratory dysfunction, which could be exacerbated by the CNS depression caused by these drugs. Pregnancy is a contraindication because of potential adverse effects on the fetus; congenital abnormalities have been reported with barbiturate use.
Use with caution in patients with acute or chronic pain because barbiturates can cause paradoxical excitement, masking other symptoms; with seizure disorders because abrupt withdrawal of a barbiturate can precipitate status epilepticus; and with chronic hepatic, cardiac, or respiratory diseases, which could be exacerbated by the depressive effects of these drugs. Care should be taken with lactating women because of the potential for adverse effects on the infant.
As previously stated, the adverse effects caused by barbiturates are more severe than those associated with other, newer sedatives/hypnotics. For this reason, barbiturates are no longer considered the mainstay for the treatment of anxiety. In addition, the development of physical tolerance and psychological dependence is more likely with the barbiturates than with other anxiolytics.
The most common adverse effects are related to general CNS depression. CNS effects may include drowsiness, somnolence, lethargy, ataxia, vertigo, a feeling of a “hangover,” thinking abnormalities, paradoxical excitement, anxiety, and hallucinations. GI signs and symptoms such as nausea, vomiting, constipation, diarrhea, and epigastric pain may occur. Associated cardiovascular effects may include bradycardia, hypotension (particularly with IV administration), and syncope.
Serious hypoventilation may occur, and respiratory depression and laryngospasm may also result, particularly with IV administration. Hypersensitivity reactions, including rash, serum sickness, and Stevens–Johnson syndrome, which is sometimes fatal, may also occur.
Increased CNS depression results if these agents are taken with other CNS depressants, including alcohol, antihistamines, and other tranquilizers. If other CNS depressants are used, dose adjustments are necessary.
There often is an altered response to phenytoin if it is combined with barbiturates; evaluate the patient frequently if this combination cannot be avoided. If barbiturates are combined with monoamine oxidase (MAO) inhibitors, increased serum levels and effects occur. If the older sedatives/hypnotics are combined with MAO inhibitors, patients should be monitored closely and necessary dose adjustments made.
In addition, because of an enzyme induction effect of barbiturates in the liver, the following drugs may not be as effective as desired: oral anticoagulants, digoxin, tricyclic antidepressants (TCAs), corticosteroids, oral contraceptives, estrogens, acetaminophen, metronidazole, phenmetrazine, carbamazepine, beta-blockers, griseofulvin, phenylbutazones, theophyllines, quinidine, and doxycycline. If these agents are given in combination with barbiturates, patients should be monitored closely; frequent dose adjustments may be necessary to achieve the desired therapeutic effect.
barbiturate – n. 巴比妥酸盐
addiction – n. 成瘾
latent – a. 潜伏的，潜在的
porphyria – n. 卟啉病
paradoxical – a. 反常的，矛盾的，异常的
mask – n. v. 帽子，掩盖
withdrawal – n. 戒断，戒断症
precipitate – v. 促成，使突然发生
status epilepticus – 癫痫状态
mainstay – n. 主流，唯一依靠
depression – n. 抑制
somnolence – n. 多寐
hangover – n. 宿醉，残余
Stevens–Johnson syndrome --斯-约二氏综合征
tranquilizer – n. 镇静剂
TCAs -- tricyclic antidepressants三环抗抑郁剂
Metronidazole – n. 甲硝唑
phenmetrazine -- n. 芬美曲秦
carbamazepine – n. 卡马西平
griseofulvin – n. 灰黄霉素
phenylbutazone – n. 保泰松
1. A client with a history of abusing barbiturates abruptly stops taking the medication. The nurse should give priority to assessing the client for:
A. Depression and suicidal ideation
B. Tachycardia and diarrhea
C. Muscle cramping and abdominal pain
D. Tachycardia and euphoric mood 2. Honey, a 23-year old client complains of substernalchest pain and states that her heart feels like “it’s racing out of the chest”. She reports no history of cardiac disorders. The nurse attaches her to a cardiac monitor and notes sinus tachycardia with a rate of 136 beats/minutes. Breath sounds are clear and the respiratory rate is 26 breaths/minutes. Which of the following drugs should the nurse question the client about using?
A. Barbiturates
B. Opioids
C. Cocaine
D. Benzodiazepines
奥医教育ISPN / NCLEX-RN “在线自测”题库，复习练习效果检验一站完成
答案 Key to Questions
1. B. Tachycardia and diarrhea
Barbiturates create a sedative effect. When the client stops taking barbiturates, he will experience tachycardia, diarrhea, and tachypnea. Answer A is incorrect even though depression and suicidal ideation go along with barbiturate use; it is not the priority. Muscle cramps and abdominal pain are vague symptoms that could be associated with other problems. Tachycardia is associated with stopping barbiturates, but euphoria is not. 2. C. Cocaine
Because of the client’s age and negative medical history, the nurse should question her about cocaine use. Cocaine increases myocardial oxygen consumption and can cause coronary artery spasm, leading to tachycardia, ventricular fibrillation, myocardial ischemia, and myocardial infarction. Option A: Barbiturate overdose may trigger respiratory depression and slow pulse. Options B and D: Opioids can cause marked respiratory depression, while benzodiazepines can cause drowsiness and confusion.
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