Barbiturates secobarbital

Frequently, a preoperative sedative is given to a patient 1 to 2 hours before the administration of general anesthesia.2,36 Sedatives are usually administered orally or by intramuscular injection, and are given while the patient is still in his or her room. This approach serves to relax the patient and reduce anxiety when arriving at the operating room. Commonly used preoperative sedatives include barbiturates (secobarbital, pentobarbital), opioids (butorphanol, meperidine), and benzodiazepines (diazepam, lorazepam) (Table 11-2). Different sedatives are selected depending on the patient, the type of general anesthesia used, and the preference of the physician. 

Methyprylon (Nodular) was introduced as a sedative and hypnotic in 1955. Its effects are nearly identical to the barbiturate secobarbital (Seconal) it acts by raising the... 

Short-acting Short-acting barbiturates (Secobarbital Seconal), pentobarbital (Nembutal) induce sleep... 

A single case report describes greatly increased sedation with severe CNS toxicity in a woman given pethidine after she took phe-nobarbital for two weeks. The analgesic effects of pethidine can be reduced by barbiturates. Secobarbital increases the respiratory depressant effects of morphine. Other barbiturates would also be expected to increase the CNS depressant effects of opioids. 

Although most anesthetics are achiral or are adininistered as racemic mixture, the anesthetic actions are stereoselective. This property can define a specific, rather than a nonspecific, site of action. Stereoselectivity is observed for such barbiturates as thiopental, pentobarbital, and secobarbital. The (3)-enantiomer is modestly more potent (56,57). Additionally, the volatile anesthetic isoflurane also shows stereoselectivity. The (3)-enantiomer is the more active (58). Further evidence that proteins might serve as appropriate targets for general anesthetics come from observations that anesthetics inhibit the activity of the enzyme luciferase. The potencies parallel the anesthetic activities closely (59,60). 

Allyl-5-(l-methylbutyl) barbituric acid (secobarbital Seconal)... 

Figure 11.19 SPME-CE analysis of urine samples (a) blank urine (a) directly injected and extracted for (b) 5 (c) 10 and (d) 30 min (b) Urine spiked with barbiturates, extracted for (e) 30 and (f, g) 5 min. Peak identification is as follows 1, pentobaitibal 2, butabarbital 3, secobarbital 4, amobarbital 5, aprobarbital 6, mephobarbital 7, butalbital 8, thiopental. Concenti ations used are 0.15-1.0 ppm (e, f) and 0.05-0.3 ppm (g). Reprinted from Analytical Chemistry, 69, S. Li and S. G. Weber, Determination of barbiturates by solid-phase microexti action and capillary electrophoresis, pp. 1217-1222, copyright 1997, with permission from the American Chemical Society.

The ultra-short-acting barbiturates include methohexital sodium (Brevi-tal) and thiopental sodium (Pentothal). These agents are used as anesthetics and are administered intravenously. Barbiturates with short-to-intermediate duration of action are used for their sedative-hypnotic effect in the treatment of anxiety. These medications include amobarbital (Amytal), butabarbital (Butisol), sodium pentobarbital (Nembutal), and secobarbital (Seconal). 

Death from overdose of barbiturates may occur and is more likely when more than 10 times the hypnotic dose is ingested. The barbiturates with high lipid solubility and short half-lives are the most toxic. Thus the lethal dose of phenobarbital is 6—10 g, whereas that of secobarbital, pentobarbital, or amo-barbital is 2-3 g. Symptoms of barbiturate poisoning include CNS depression, coma, depressed reflex activity, a positive Babinski reflex, contracted pupils (with hypoxia there may be paralytic dilation), altered respiration, hypothermia, depressed cardiac function, hypotension, shock, pulmonary complications, and renal failure. 

Secobarbital exhibits the same pharmacologic properties as other members of the barbiturate class. Most nonmedical use is with short-acting barbiturates, such as secobarbital. Although there may be considerable tolerance to the sedative and intoxicating effects of the drug, the lethal dose is not much greater in addicted than in normal persons. Tolerance does not develop to the respiratory effect. The combination of alcohol and barbiturates may lead to fatalities because of their combined respiratory depressive effects. Similar outcomes may occur with the benzodiazepines. Severe withdrawal symptoms in epileptic patients may include grand mal seizures and delirium. 

A few barbiturates also contain an allylic group at C(5), e.g., allobarbi-tal (10.64, R = allyl), alphenal (10.64, R = Ph), aprobarbital (10.64, R = i-Pr), and secobarbital (10.64, R = 1-methylbutyl). These compounds were substrates of the epoxide-diol pathway in rats and guinea pigs. The relative... 

Barbiturates. The hrst barbiturate, barbital, was introduced in 1903 and was followed a few years later by phenobarbital. The barbiturates effectively relieve anxiety, but they are never used as anxiolytics today due to toxicity and abuse concerns. However, several barbiturates, including phenobarbital (Luminal), secobarbital (Seconal), and pentobarbital (Nembutal), remain available and are occasionally used to treat epilepsy and rarely to manage acute alcohol withdrawal. 

Secobarbital Secobarbital, 5-aUyl-5-(l-methylbutyl)barbituric acid (4.1.14), is also synthesized by the same standard schema of reacting a-allyl-a-(l-methylbutyl)-malonic ester with urea [14]. 

The CNS depressants include barbiturates, nonbarbiturate sedatives, and the benzodiazepines. As the medical use of barbiturates decreased, primarily because of their high addiction liability and the danger of acute lethality, the use of the benzodiazepine anxiolytics increased. The most commonly abused barbiturates are secobarbital, pentobarbital, and amobarbital. Pheno-barbital is not generally abused, because of its slow onset of action. The most commonly abused anxiolytics include diazepam, chlordiazepoxide, midazolam, lo-razepam, and flurazepam. These drugs are readily attainable from illicit sources. 

Cyclic thioureas such as 2-thiouracil 1118 (R = H), its 6-methyl 1118 (R = Me) and 6-propyl derivatives 1118 (R = Pr), as well as thiobarbital 1119 are effective agents against hyperthyroidism, while thiamylal 1120 is used as an anesthetic. A large number of barbituric acid derivatives have hypnotic or sedative effects, and allobarbital 1121 (R = R = allyl), aprobarbital 1121 (R = allyl, R = r-Pr), cyclobarbital 1121 (R = Et, R = 1-cyclohexenyl), pentobarbital 1121 (R = Et, R = 2-pentyl), phenobarbital 1121 (R = Et, R = Ph), propallyonal 1121 (R = isopropyl, R = 2-bromoallyl), and secobarbital 1121 (R = allyl, R = 2-pentyl) are all examples of N-unsubstituted barbiturates, while hexobarbital 1122 represents an N-methylated derivative. 

Contraindications History of manifest or latent porphyria, marked liver dysfunction, marked respiratory disease in which dyspnea or obstruction is evident, and hypersensitivity to secobarbital or barbiturates... 

Sedatives (also called hypnotics, sedative-hypnotics, minor tranquilizers, antianxiety agents) Secobarbital (barbiturate) Glutethimide (nonbarbiturate hypnotic) Diazepam (benzodiazepine antianxiety agent) Chloral hydrate (miscellaneous hypnotic) alcohol ( substance )... 

Barbiturates amobarbital sodium pentobarbital sodium phenobarbital secobarbital sodium... 

Barbiturate drugs like pentobarbital (Nembutal ), secobarbital (Seconal ), amobarbital (Amytal ), and phenobarbital are extremely potent sedatives that induce sleep, mostly non-REM sleep. However, barbiturates actually decrease the amount of REM sleep a person gets. Thus, if a person took a barbiturate as a sleep aid nightly for a week, the total amount of REM sleep would be significantly less than if he or she was not taking the drug. Then, when the person stopped taking the barbiturate, he or she would experience a severe REM... 

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