What Are the Most Common Phenobarbital Side Effects?

Barbital is a colorless needle-like crystal or white powder. Melting point 188-192 ° C, soluble in hot water, ethanol, ether, chloroform. Dissolved in alkali hydroxide solution or alkali carbonate solution. Odorless and slightly bitter. This product can be used as a hypnotic drug. Due to safety, effectiveness, and resistance to repeated use, barbiturates have been used as a hypnotic drug. Barbitur tablets are one of the phase-out drugs announced by the Ministry of Health in September 1982. Barbital can be used as a hydrogen peroxide stabilizer; it is used to prepare buffer solutions, protein electrophoresis, and liver function tests.

It is an earlier-acting long-acting barbiturate hypnotic, which has different levels of central inhibitory effects such as sedation, hypnosis, anticonvulsions, and anesthesia. Its advantages are slow action and long maintenance time. Effective after 30 to 60 minutes after oral administration, and maintained for 6 to 8 hours. In addition, the combination of barbiturate and antipyretic analgesics can enhance the analgesic effect of the latter. ^[3]

Sedation and hypnosis; large doses can prevent convulsions and anesthesia. Effects appear slow and last long. ^[3]

1. Sedation: such as anxiety, irritability, hyperthyroidism, hypertension, functional nausea, pyloric spasm in children.

2. Sleep: Occasionally used for refractory insomnia, but after waking there are often after effects such as fatigue, sleepiness and so on.

3. Anti-convulsions: commonly used to fight convulsions caused by central stimulant poisoning or high fever, tetanus, encephalitis, cerebral hemorrhage and other diseases.

4. Anti-epilepsy: for the prevention and treatment of epilepsy, the effect appears quickly, and it can also be used for the status of epilepsy.

5. Administration before anesthesia.

6. Compatible with antipyretic and analgesics to enhance its effect.

7. Treatment of neonatal jaundice. Long-term use can cause morbid dependence. ^[3]

This product is a long-acting hypnotic drug with sedative, hypnotic, anticonvulsant and antiepileptic effects. It can also be used as an anesthetic before administration. When combined with antipyretic and analgesics, it can enhance the analgesic effect of the latter. These years have reported that this product can be used to prevent neonatal hyperbilirubinemia and cerebral nuclear jaundice, and can also treat cholestasis. After the addition of phenobarbital to patients with cerebral edema, cerebral edema and cerebral hernia improved quickly, blood pressure was easy to stabilize, and cerebral vasospasm and rebleeding were also reduced. Oral administration of this product combined with intramuscular chorionic gonadotropin treatment of primary infertility. Polycystic egg syndrome can also be treated to reduce the incidence of intracranial hemorrhage in preterm infants. Oral administration of this product can also increase the effect of papaverine on cerebral vasospasm and other diseases. ^[3]

Tablets: 0.01g, 0.015g, 0.03g, 0.1g each. Phenobarbital sodium for injection: 0.1g each. Barbiturates are a group of central inhibitors obtained by replacing barbituric acid at the C5 position. Substituents that are long and branched (such as isoprene barbitur) or double bonds (such as sercobarbital) are strong and short; substitution with a phenyl ring (such as phenobarbital) has stronger anticonvulsants Effect; O at the C2 position is replaced by S (such as thiopental), the fat solubility increases, intravenous injection takes effect immediately, but the maintenance time is short. Table 14-2 Comparison of barbiturate effects and uses

Subclass	drug	Effective time (hours)	Effect maintenance time (hours)	The main purpose
Long-lasting	Phenobarbital	0.5 1 0.5 1	6 8 6 8	Anticonvulsant sedation hypnosis
Medium effect	Pentobarbital	0.25 0.5 0.25 0.5	3 6 3 6	Anticonvulsant sedation hypnosis
Short-acting	Scobarbital	0.25	2 3	Anticonvulsant sedation hypnosis
Ultra short-lived	Thiopental sodium	iv immediately	0.25	Intravenous anesthesia

1. 0.3 0.6g, take 0.5 hours before bedtime.

2. Sedation: 0.3 ~ 0.9g per day, divided into 2 ~ 3 times.

3. Administration before anesthesia: 0.3g, taking 40 ~ 60min before operation.

4. Anticonvulsions: intramuscular injection with barbiturate sodium injection, 0.2g each time. Or enema with 5% solution, 0.5g each time. ^[3]

Similar to phenobarbital, there will be feelings of depression and dizziness in the morning after hypnosis; a few have rash and fever. Prolonged use can produce tolerance and dependence. Large doses can inhibit the respiratory center, and severe cases may die of respiratory paralysis. Patients with severely impaired liver, lung, and kidney function are prohibited. ^[3]

Prolonged use can produce tolerance and addiction. Repeated use should be alert to accumulation of poisoning. A few patients may develop allergic reactions such as rash, exfoliative dermatitis, and fever. It should not be stopped suddenly when used for anti-epilepsy, so as not to cause rebound phenomenon. Alcohol should be banned during medication, and those with liver and kidney dysfunction should be used with caution. Its sodium salt aqueous solution is unstable and should not be stored. The Ph value of the solution is 9.7. Mixing with drugs with a lower pH value often results in precipitation, so it should not be mixed with other drugs for injection. Sealed and protected from light.

1. After-effects such as dizziness and drowsiness may occur after medication, and prolonged use can produce tolerance and addiction. Repeated use should be alert to accumulation of poisoning. 2. A small number of patients may develop allergic reactions such as rash, drug fever, and exfoliative dermatitis. 3. For long-term use in the treatment of epilepsy, do not stop the medicine suddenly, so as not to cause seizures, and even the state of epilepsy. 4. General application of 5 to 10 times the amount of hypnosis can cause moderate poisoning, 10 to 15 times can cause severe poisoning, blood concentration is higher than 8 ~ 10mg / 100ml, there is danger to life. The symptoms of acute poisoning are drowsiness, which leads to superficial breathing, greatly reduced ventilation, and eventually death due to respiratory failure. 5. Use with caution or forbidden for severe pulmonary dysfunction (such as emphysema), bronchial asthma, and brain injury with suppressed respiratory center; use with caution for patients with poor liver and kidney dysfunction, and with cirrhosis or severe liver dysfunction. 6. First aid for poisoning of this product or other barbiturates: If the product is taken orally for less than 3 hours, a large amount of warm isotonic saline or 1: 2000 potassium permanganate solution can be used for gastric lavage. ^[3]

Barbiturates are universal central inhibitors. With the dose from small to large, sedative, sleeping, anticonvulsant and anesthetic effects occur one after another. At 10 times the amount of hypnosis, it can inhibit breathing and even cause death.

Barbiturates mainly inhibit multisynaptic responses, reduce facilitation, and enhance inhibition at non-narcotic doses. This effect is mainly seen in synapses transmitted by GABAergic nerves. It enhances GABA-mediated Cl influx and weakens glutamate-mediated depolarization. But unlike benzodiazepines, barbiturates increase Cl inflow by prolonging the opening time of the chlorine channel, causing hyperpolarization. At higher concentrations, it inhibits Ca-dependent action potentials, inhibits Ca-dependent transmitter release, and exhibits a pseudo-GABA effect, which can directly increase Cl inflow without GABA.

Such drugs require anti-anxiety effects at sedative doses. Because this class of drugs is far less safe than benzodiazepines and is more prone to dependence, it is now rarely used for sedation and hypnosis. Only phenobarbital and pentobarbital are still used to control the status of epilepsy; thiopental is occasionally used for minor anesthesia or intravenous anesthesia during endoscopy.

Barbiturates inhibit the pontine reticular structure and reduce REM sleep. Even if the drug is stopped for a short period of time, it may cause a rebound in REM sleep, which is manifested as a continuous nightmare and uncomfortable feeling. Therefore, once a barbiturate is taken, it tends to be taken continuously, and it is more difficult to stop, so it is easy to form dependence. Dependants are mostly taking drugs that act for a short period of time, such as Scopolamine, Ammeter, and Pentobarbital. The general addictive dose is 4 to 50 times the therapeutic amount. This class of drugs has cross-resistance with alcohol. Drinking with barbiturates can accelerate addiction. Sometimes it can be addictive at a time.

(1) Addiction effect. After taking the medicine, it can relieve the tension and anxiety, and produce a sense of drowsiness and forgetfulness, which leads to a strong desire to continue taking the medicine, and even reaches the point of not taking the medicine, forming a strong psychological dependence. At the same time, patients often develop symptoms of chronic poisoning.

(2) Chronic poisoning.

Main manifestations are: ataxia, unstable gait, unclear speech, awkward movement, poor discrimination, nystagmus; slow understanding, difficult thinking, poor memory, and wrong judgment; emotional instability, irritability, Mood and stubbornness, stubbornness, and conflict with others; Unscrupulous living, untidy clothing, unscrupulous behavior, hypersexuality, and poor moral concepts; Poisonous psychosis can occur.

(3) Withdrawal symptoms.

Awake period: several hours to 24 hours after drug withdrawal. Presentation of fatigue, anxiety, decreased blood pressure, orthostatic collapse, absence of seizures, tachycardia, insomnia, etc.

Spasticity period: It is more common about 1 to 3 days after withdrawal of the drug, especially on the second day. Seizures are common and even persistent. At the same time, there are insomnia, coarse tremor, and hyperkinesia. EEG examination found abnormalities.

delirium period: often appear immediately after the convulsive period. Delirium is the most important at night, which is mainly manifested by disturbance of consciousness and uncoordinated psychomotor excitement. If accompanied by high fever, it can be life-threatening. Usually after 5 days, the delirium disappears, and a major spasm can still occur on the 7th day. Sometimes this period can last for about 2 weeks.

Hallucinations and delusions: Schizophrenia-like hallucinations and delusions can occur, accompanied by horror, and can last for a long time, up to about two months.

Period of emotional instability: emotional instability, changeability, irritability, and reduced endurance can last for weeks to months.

Barbiturates: These drugs are derivatives of barbiturates. Its role is to inhibit the function of the central nervous system, mainly to block the conduction of the brainstem reticular structure to activate the system upwards, reduce the impact of afferent impulses on the cerebral cortex, thereby causing sedative and hypnotic effects. Barbiturates have the same effect in 4 books. But the effect is different and the duration is different. High fat solubility is easy to enter the human brain tissue through the blood-brain barrier. The effect is fast and strong. Low fat solubility is slow to enter the human brain tissue. The effect is also slow.

I. Phenobarbital, also known as Lumina: Phenobarbital has an inhibitory effect on the central nervous system. With the increase of the dose, it can produce sedative, hypnotic and anticonvulsant effects. Its effect lasts 6-8 hours. It can shorten people's sleep time and prolong sleep time, but accompanied by multiple dreams. Can be used for anxiety, insomnia and pre-anesthetic administration, combined with antipyretic and analgesics can increase its analgesic effect. Larger doses have anticonvulsant effects, and are used for large episodes of narcotic pain and tetanus. In addition, it can treat neonatal brain nucleus jaundice because it can induce liver microsomal glucuronyltransferase, promote the combination of bilirubin and grape glucuronide, and reduce the plasma bilirubin concentration.

Usage and Dosage: 15-30 mg orally for adults outside the town. 3 times a day. 30-100 mg for hypnotic adults each time, before bedtime; 250 mg for extreme doses, 500 mg per day. Toxic side effects: There are often persistent effects such as drowsiness, dizziness, and depression. Occasionally allergic reactions such as rash, exfoliative dermatitis, motor dysfunction, jaundice, toxic hepatitis, etc. Acute poisoning may occur beyond the dose site, causing symptoms such as lethargy, respiratory depression, tachycardia, decreased blood pressure, shock, etc., and eventually die due to anesthesia of the respiratory center. Preparations and specifications: 30 mg / tablet, 100 mg / tablet. Note: long-term application can produce tolerance and dependence. Repeated application or excessive dose can accumulate poisoning. It is necessary to control the use. Elderly patients should be reduced, liver and kidney dysfunction, respiratory dysfunction, craniocerebral injury and phyllophylopathy should be disabled. It can enhance the central inhibitory effect of other middle frame inhibitors. Valproate can inhibit phenobarbium The metabolism of betto should be reduced in the latter when combined.

2. Isoprenebarbital, also known as Amitole: This product has a similar effect to phenobarbital, its fat solubility is high, it is easy to penetrate the blood-brain barrier, and its effect is faster. Medicine, sleep for 15-30 minutes, for simple insomnia and sedation during anxiety and tension. The injection is mainly used for anticonvulsants, such as the rescue of children with epilepsy and high fever and epilepsy. Usage and Dosage: Sedative adults take 20-40 mg orally each time, 2-3 times a day. Hypnotic adults 100-200 mg, take before bedtime. Toxic effects: same as phenobarbital. Preparations and specifications: tablets, 100 mg / tablet. Note: This product is addicted to prolonged use and should not be used for a long time. The injection is unstable and should be used now. Other precautions are the same as phenobarbital.

3. Sodium pentobarbital: This product has the same effect as isobarbital, and is a medium-effect drug. Effective 15 minutes after oral administration and maintained for 3-6 hours. Clinically used for hypnosis and effective for all types of insomnia. Administration before anesthesia can prevent convulsions.

Usage and Dosage: Hypnosis: Adults take 100-200 mg orally each time. Toxic effects: same as phenobarbital. Preparations and specifications: tablets, 50 mg / tablet Note: Isoprene barbiturate. 4) Scopolamine is also known as scobarbital sodium. This product is a short-acting barbiturate, which has a similar effect to phenobarbital, but it has a fast onset of action. It will sleep in 15-20 minutes after oral administration and maintain 3 About hours. It is used clinically for insomnia with difficulty sleeping, but also for tension, anxiety, excessive excitement, sedation before anesthesia and before surgery. Usage and Dosage: Sedative adults take 50 mg orally each time, 3 times a day. 100-200 mg of hypnotic adult, taken before bedtime. Toxic effects: same as phenobarbital. Preparations and specifications: capsules, 100 mg / capsule. Note: Continuous application is easy to produce tolerance. When applied for 1-2 weeks, the hypnotic effect is significantly reduced, and long-term use can also produce dependence. Use should be strictly controlled. Others are similar to phenobarbital.

The commonly used drugs for clinical treatment of insomnia and more dreams are Yangxue Anshen Tablets, Jieyu Anshen Granules, Ye Ning Granules and so on.