An overview of Barbital

Barbital, also known as barbitone, is the first commercial Barbital. From 1903 to the mid-1950s, Barbital were used as hypnotics. The chemical name of Barbital is diethylmalonylurea or diethylbarbituric acid. In the presence of sodium ethoxide, the flonarone can be obtained by reacting the 2,2-diethyl-substituted malonate with urea, or by adding iodoethane to the silver salt of the malonylurea. Barbital are an odorless, slightly bitter white crystalline powder.

Synthesis history

Barbital was first synthesized in 1902 by German chemists Emil Fischer and Josef, BaronvonMering. Their discovery was first published in 1903. 1904 Bayer company will barbiturate trade name as "flona". Schering later sold barbiturate sodium (a soluble salt of Barbital) under the trade name Medinal, calling it "insomnia caused by nerve stimulation," which is usually sold in capsules. The recommended dose is 10 to 15 grains (0.65 to 0.97 grams) and a lethal dose of 3.5 to 4.4 grams. But there are also improper administration of lethargy as long as ten days later later recovered the case.

Chemical properties

1, weak acid

(1) the hydrolysis of Barbital: the basic structure of the imide structure, with the alkaline solution that is azeotropic hydrolysis of ammonia.

(2) the hydrolysis of sodium barbiturate: in the case of moisture absorption, the sodium salt of this class of drugs can also be hydrolyzed into a void substance.

2, hydrolysis reaction

3, and heavy metal ions reaction

(1) reaction with a silver salt

(2) Reaction with copper salt (Zwikker reaction) When the imide structure is dissolved in pyridine, the enolate isomerization is easy to occur, and the structure of the enolate structure is in agreement with the copper pyridine solution to form a stable coordination compound.

Barbiturate Corydalis color, thiobarbital was green.

(3) Reaction with cobalt salt (Parri test) Reaction conditions:

① anhydrous conditions ② common reagents: anhydrous ethanol or methanol, cobalt acetate, cobalt nitrate or cobalt oxide; ③ alkaline: isopropylamine or pyridine.

(4) the reaction with the mercury salt (occurred in 1)

With mercury nitrate or mercuric chloride test solution reaction, resulting in white mercury salt precipitation, precipitation can dissolve in ammonia solution, precipitation dissolved.

Classification of Barbital

Overview Barbital commonly used in clinical medicine, according to their duration of action can be divided into four categories:

(1) long-acting class, including barbital and phenobarbital (Rumil), the role of time 6-8 hours;

(2) medium effect class, including isobarbital (amitol), the role of time 3-6 hours;

(3) short-acting class, including the Secretary may barbital (speed can sleep), the role of time 2-3 hours;

(4) ultra-short-acting class, mainly thiopental sodium, the role of time in less than 2 hours.

The use of Barbital

The product is a long-acting hypnotics, with sedative, hypnotic, anticonvulsant and antiepileptic effect.

Can also be used as pre-anesthesia administration, combined with antipyretic analgesics can enhance the analgesic effect of the latter.

Reported in recent years, the goods can be used to prevent neonatal hyperbilirubinemia and cerebral nuclear jaundice, but also treatment of cholestasis disease. Cerebral edema patients with phenobarbital, cerebral edema hernia improved quickly, blood pressure and stability, cerebral vasospasm and rebleeding is also reduced.

Oral administration of the goods with the intramuscular injection of chorionic gonadotropin treatment of primary infertility. Polycystic ovary syndrome can also be treated to reduce the incidence of intracranial hemorrhage in premature infants.

Oral administration of this product can increase the papaverine on cerebral vasospasm and other diseases.

Clinical manifestations

1. mild poisoning: drowsiness, but easy to wake up, speech is unclear, feeling insensitive, there are judgments and disorientation, a variety of reflection exists, temperature, pulse, respiration, blood pressure were normal.

2. Moderate poisoning: sleeping, a strong push to wake up, but not all awake, can not ask, spin into the coma. Tendon reflex, breathing slower but shallow, normal blood pressure, corneal reflex, pharyngeal reflex is still there may be a lips, fingers or nystagmus.

3. Severe poisoning: deep coma, early may have limb rigidity, hyperreflexia, ankle clonidine, plan test positive foot, late systemic relaxation, a variety of reflex. Pupillary light reaction exists, sometimes dilated pupils, and sometimes narrow, shallow breathing slow, irregular or tidal breathing, pulmonary edema can occur (short-acting poisoning occurs), late due to hypostatic pneumonia and dyspnea even more . Pulse rate, blood pressure, severe shock, oliguria, or urinary retention, azotemia, etc., and ultimately may be due to respiratory center paralysis, shock or long-term coma complicated with pulmonary infection and death.

Treatment principles

1. Gastric lavage: medication does not exceed three hours, available 1: 4000 potassium permanganate solution gastric lavage.

2. Sleeping or coma, close observation, careful care.

3. intravenous infusion of glucose and intravenous furosemide, to promote the excretion of barbiturates.

4. To maintain blood pressure treatment and anti-infection, supportive therapy.

5. Excited respiratory center treatment.

6. critically ill hemodialysis treatment.