The barbiturates are nonselective central nervous structure depressants which are primarily used as sedative hypnotics and also anticonvulsants in subhypnotic doses. The barbiturates and their sodium salts are subject to manage under the Federal Controlled Substances Act

The sodium salts of amobarbital, pentobarbital, phenobarbital, and secobarbital are accessible as sterile parenteral solutions.

Barbiturates are substituted pyrimidine derivatives in which the basic structure common to these drugs is barbituric acid, a substance which has no central nervous system (CNS) activity. CNS activity is obtained by substituting alkyl, alkenyl, or aryl groups on the pyrimidine ring.

Pentobarbital Sodium Injection, USP is a sterile resolution for intravenous or intramuscular injection. Each mL contains pentobarbital sodium 50 mg, in a vehicle of propylene glycol, 40%, alcohol, 10% v/v and water for injection, to volume buy sodium pentobarbital uk. The pH is accustomed to approximately 9.5 with hydrochloric acid and/or sodium hydroxide.

Pentobarbital Sodium Injection, USP is a short-acting barbiturate, chemically nominated as sodium 5-ethyl-5-(1-methylbutyl) barbiturate.

Barbiturates are capable of producing all levels of CNS mood adjustment from excitation to mild sedation, to hypnosis, and deep coma. Overdosage can produce death. In elevated enough therapeutic doses, barbiturates induce anesthesia.

Barbiturates discourage the sensory cortex, decrease motor movement, alter cerebellar function, and produce drowsiness, sedation, and hypnosis.

Barbiturate-induced sleep differs from physiological sleep. Sleep laboratory studies have demonstrated that barbiturates reduce the amount of time spent in the rapid eye movement (REM) phase of sleep or dreaming phase. Also, Stages III and IV sleep are decreased. Following abrupt cessation of barbiturates used regularly, patients may experience markedly increased dreaming, nightmares, and/or insomnia. Therefore, withdrawal of a single therapeutic dose over 5 or 6 days has been recommended to lessen the REM rebound and disturbed sleep which contribute to drug withdrawal syndrome (for example, decrease the dose from 3 to 2 doses a day for 1 week).

In studies, secobarbital sodium and pentobarbital sodium have been create to lose most of their effectiveness for both inducing and maintaining sleep by the end of 2 weeks of continued drug administration at fixed doses. The short-, intermediate-, and, to a lesser degree, long-acting barbiturates have been broadly prescribed for treating insomnia. Although the clinical literature abounds with claims that the short-acting barbiturates are superior for producing sleep while the intermediate-acting compounds are more effective in maintaining sleep, controlled studies have failed to demonstrate these differential effects. Therefore, as sleep medications, the barbiturates are of limited value beyond short-term use buy pentobarbital sodium

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Barbiturates have little analgesic action at subanesthetic doses. Rather, in subanesthetic doses these drugs may increase the reaction to hurting stimuli. All barbiturates reveal anticonvulsant activity in anesthetic doses. However, of the drugs in this class, only phenobarbital, mephobarbital, and metharbital have been clinically demonstrated to be effective as oral anticonvulsants in subhypnotic doses.

Barbiturates are respiratory depressants. The degree of respiratory depression is dependent upon dose. With hypnotic doses, respiratory sadness produced by barbiturates is similar to that which occurs during physiologic sleep with slight decrease in blood pressure and heart rate.

Studies in laboratory animals have exposed that barbiturates source decline in the tone and contractility of the uterus, ureters, and urinary bladder. However, concentrations of the drugs required to manufacture this result in humans are not reached with sedative-hypnotic doses.

Barbiturates are absorbed in varying degrees following oral, rectal, or parenteral administration. The salts are more swiftly absorbed than are the acids.

The onset of action for oral or rectal administration varies from 20 to 60 minutes. For IM administration, the onset of action is slightly quicker. Following IV administration, the onset of action ranges from approximately directly for Pentobarbital Sodium to 5 minutes for phenobarbital sodium. Maximal CNS depression may not occur until 15 minutes or more after IV administration for phenobarbital sodium.