Among the various sleeping pills and painkillers of a narcotic nature, “Thiopental sodium” occupies a special place. Instructions for use of this serious potent drug are of interest to many patients. What is this pharmacological agent? In what cases is its appointment justified? What is the mechanism of action of “Thiopental sodium” and how should it be used? Can the drug cause side effects and what to do in case of an overdose? The answers to these questions are given by the instructions for use of “Thiopental sodium”.
Briefly about the drug
Before purchasing the drug, it will be necessary to take the prescription “Thiopental sodium” in the Latin language from the doctor in charge. This drug has a strong narcotic effect, so it can not be purchased without a doctor’s prescription.
What is a medicine? At the pharmacological market, it is sold in the form of a light hygroscopic powder, from which a solution for intravenous administration can be prepared. The powder, one or half a gram, is packaged in glass bottles with a capacity of ten or twenty milliliters.
Briefly about the composition
The active ingredient of the pharmacological agent of interest to us is the substance of the same name - Thiopental sodium. This is how the name will be written in the recipe “Thiopental sodium” in Latin.
The active ingredient is a derivative of barbituric acid. Used as non-inhalation anesthesia. How is the desired effect of the drug achieved?
Effects on the body
What happens when a medicine enters the bloodstream? How does sodium thiopental affect the human body? The pharmacological group of this drug is anesthesia for intravenous administration with a general anesthetic and hypnotic effect of short action.
Once in the bloodstream, the active substance inhibits the respiratory and vasomotor centers, as well as the myocardium. Gradually, as a result of this effect, the blood pressure and pulse of the patient decrease, muscle relaxation is felt.
“Thiopental sodium” slows down the opening of channels that depend on exposure to gamma-aminobutyric acid, and also increases the time it takes for chlorine ions to enter the nerve cell. Also, the drug reduces the stimulating effect of amino acids such as glutamate and aspartate.
It is noteworthy that the drug that interests us has an anticonvulsant effect. This is achieved by increasing the threshold of excitability of neurons and blocking the conduct and distribution of convulsive impulses throughout the brain. Also, the drug reduces the intensity of certain processes occurring in the brain.
How long to wait for the action of "Thiopental sodium"? The drug when administered intravenously begins to act after thirty seconds, with rectal use - after eight to ten minutes.
How long does the medication last? As the instruction shows, the duration of anesthesia varies between twenty to thirty minutes. After this period, the patient wakes up. According to the instructions, “Thiopental sodium” does not cause drowsiness after waking up. The duration of the analgesic effect ends at the moment when the patient comes to his senses.
Pharmacokinetic features
When administered intravenously, the drug penetrates through the bloodstream into the brain, adipose tissue, liver, skeletal muscles and kidneys in forty-sixty seconds. Due to the fact that the active substance spreads rapidly throughout all body tissues, its effect passes soon enough.
Binding to plasma proteins of the drug averages eighty percent. With a single administration, the half-life of the active substance ranges from three to eight hours. In children, this process is the fastest - a little over an hour. This time period increases in women carrying babies (up to 26 hours), and in people suffering from obesity (about 27 hours).
The drug we are interested in is metabolized in the liver, excreted through the kidneys. It is noteworthy that the drug has a cumulative effect. This is possible with repeated administration of anesthesia. In this case, “Thiopental sodium” accumulates in fatty tissues.
In what cases is it justified to prescribe this anesthetic?
Indications for use of the drug
Most often, a medication is prescribed for short surgical interventions as a general anesthesia. In some cases, the drug acts as an introductory or basic anesthesia. That is, after its introduction, it will be necessary to use other, more potent drugs for anesthesia or anesthesia.
In some cases, “Thiopental sodium” can be used to treat a patient with epileptic status or increased intracranial pressure. Injections are sometimes prescribed as prophylaxis of brain hypoxia. This is usually justified in neurosurgical operations performed on the vessels of the brain, during cardiopulmonary bypass or carotid endarterectomy.
Of course, the medication has contraindications.
When you can not use the drug
Among the main contraindications of the drug, doctors note serious pathologies of the kidneys and liver, diabetes mellitus, asthma, collapse, severe exhaustion of the body, inflammatory diseases of the nasopharynx, fever, acute circulatory disorders, history of acute porphyria in both the patient and his relatives.
In addition, you can not use this medication as anesthesia for women who are breastfeeding, as well as for patients who are diagnosed with sodium thiopental intolerance or intoxication of various origins (due to an increased dose of alcohol, sleeping pills, painkillers, etc.).
With caution, it is recommended to prescribe this drug to pregnant women, children under twelve years of age, as well as people suffering from anemia, muscular dystrophy, chronic obstructive diseases of the respiratory system, obesity, severe ailments of the cardiovascular system (insufficiency, myocardial disease), and so on.
In addition to contraindications, the drug has a number of side effects, which will be discussed in the next subheading.
Negative reactions to the medication
Before using this product as an anesthetic, the attending physician will familiarize the patient with possible negative manifestations that may occur during the use of “Thiopental sodium”.
First of all, we are talking about dizziness and lethargy, as well as memory impairment. These symptoms are most often observed in the postoperative period after using anesthesia. This is due to dose-dependent inhibition of the central nervous system. What do patients say about thiopental sodium? In the reviews of this drug, people note that they have encountered such unpleasant phenomena as convulsive seizures, muscle twitching, drowsiness and anxiety. Quite rarely, patients were disturbed by such negative reactions to anesthesia as hallucinations, back pain, confusion, and so on.
Also, according to patients' reviews, after using the drug they were disturbed by interruptions in the rhythm of the heart, lowering pressure, collapse.
The respiratory system may negatively respond to the use of anesthesia with bronchospasm, difficulty breathing, sneezing or coughing.
After applying the medication, a person may be disturbed by abdominal pain, a feeling of nausea, and vomiting.
Among other unpleasant symptoms, patients note skin rashes, hives, redness of the epidermis, and hiccups.
Immediately upon administration of the drug, a person may experience soreness or burning at the injection site, redness on the skin at the injection site, desquamation, vasospasm.
How should an anesthetic be used to minimize the number and severity of the symptoms mentioned above?
General information
As mentioned above, the drug is administered intravenously. Manipulation should be carried out very carefully and slowly. Injections are carried out only in specialized conditions, that is, within the walls of medical institutions, where the necessary devices are located to maintain cardiac activity and respiration.
Children are allowed to use the drug rectally, that is, inject the solution into the rectum.
What is the required dose of thiopental sodium to provide good anesthesia? According to the instructions for use, adults are prescribed a 2-2.5% solution, however, in some cases, the dosage can be increased to five percent. Patients of advanced age, weakened people and children are administered a one percent solution.
How to dilute "Thiopental sodium" to the required dosage?
Solution recommendations
The powder is diluted with special sterile water for injection, a five percent glucose solution, or physiological sodium chloride solution. The prepared product must be used immediately after dilution. It is unacceptable to save it or freeze it.
To prepare a five percent solution, you need to dilute one gram of powder in twenty milliliters of injection water. To prepare 1.25% of the drug, it is recommended to add forty milliliters of water to 0.5 grams of powder.
How does the breeding process go? Everything is very simple.
The required amount of liquid is collected in a syringe, and then added to the bottle with powder, after which everything is thoroughly mixed by vigorously shaking the container with the medication. The medicine should completely dissolve and become transparent, otherwise it can not be used.
Specific dosage
And now let's talk about specific dosages of the drug that can be prescribed by an anesthetist. As an anesthesia for adults, at the first stage of anesthesia, a trial amount of the drug is administered - about 25-75 milligrams. Then, after a minute, the so-called basic dose is administered at the rate of three to five milligrams of the drug per kilogram of the patient’s body weight. On average, two hundred or four hundred milligrams of the drug. Typically, this dosage is divided into two to four times and injected into the vein every thirty to forty seconds to obtain the desired effect.
However, as mentioned above, “Thiopental sodium” is used not only as anesthesia. For the treatment of complex specific conditions, the drug is prescribed in such dosages:
- To stop a seizure, 75-125 milligrams of the drug is administered for ten minutes.
- To stop the seizures that arose against the background of local anesthesia, 125-250 milligrams are also prescribed for ten minutes.
- With brain hypoxia, the medication of interest to us is administered at a rate of 1.5-3.5 milligrams per kilogram of patient weight. The injection is carried out for a minute, until a temporary stop of blood circulation begins.
- In some cases, the drug can be used for drug analysis, when a person is introduced into a semi-unconscious state so that he answers the necessary questions. In such situations, one hundred milligrams of thiopental sodium is administered for one minute until the desired state is reached.
Children and drug
Although they try not to use the medication to treat small patients, if anesthesia is necessary, the drug is prescribed in a dosage of three to five milligrams per kilogram of weight. The drug is administered jet intravenously for three to five minutes once. This dosage applies to babies up to a year.
Children from one year to twelve years old are given a drug at the rate of five to eight milligrams per kilogram of body weight.
A five percent solution of “Thiopental sodium” is prescribed rectally. The dosage of the medicine is calculated as follows: 0.04-0.05 grams for one year of life of a small patient (if the child's age does not exceed three to seven years).
Usage Cautions
Since “Thiopental sodium” is a serious potent drug for general anesthesia, only professionals should administer it based on the appointment of an anesthetist. The specialist makes a decision regarding the dosage of the drug, not only on the basis of the duration and depth of the necessary anesthesia, as well as the individual sensitivity of the patient.
The drug can only be administered intravenously. If the solution enters the artery, it can cause vessel thrombosis, necrosis, and even gangrene.
How to determine in time that the medication has entered the artery? This can be detected if a conscious patient complains of a burning sensation in the vessel. If the person is in an unconscious state, then the incorrect administration of anesthesia will be indicated by a darkening of the epidermis, transient blanching or spotted cyanosis. In this case, it is urgent to stop the manipulation, and to introduce the solution of “Heparin” at the site of the lesion. Anticoagulant therapy should also be carried out and the brachial plexus blockade should be carried out.
If the drug has come under the skin, it is necessary to introduce a local anesthetic, as well as to warm the surface of the epidermis. This activates blood circulation and will contribute to the resorption of the infiltrate.
When prescribing the drug, one should take into account the fact that people suffering from alcoholism give in poorly to its effect, so the anesthetic effect can be short-lived.
With the action of the medication, that is, the introduction of general anesthesia, it is necessary to ensure patient access to oxygen.
When using the drug for medicinal purposes, you must be aware that it is addictive.
An overdose of an anesthetic
This is very rare, but it is still important to know the unpleasant symptoms that accompany the introduction of too high a dose of the drug. What should I look for?
First of all, the patient's blood pressure may drop sharply, tachycardia, respiratory depression, bronchospasm may appear. Even pulmonary edema and cardiac arrest are possible.
In such cases, as experienced anesthetists say, it is important to administer bemegride, which is the antipode of “Thiopental sodium,” in time. To eliminate unwanted symptoms, appropriate therapy is used. For example, when you stop breathing, oxygen or mechanical ventilation is prescribed, with convulsions, diazepam is administered, and so on. In some exceptional cases, muscle relaxants may be needed.
Interaction with other medicines
According to the instructions, “Thiopental sodium” is able to reduce the effect of contraceptives, coumarin derivatives (indirect anticoagulants), glucocorticosteroids and griseofulvin. It is strictly forbidden to take this medication with muscle relaxants, ascorbic acid, atropine, antibiotics, tranquilizers, tubocurarine chloride, scopolamine, ephedrine and so on.
If you use an anesthetic together with antihypertensive drugs, ganglion blockers or diuretics, then a sharp decrease in pressure is possible. The same is possible with the parallel appointment of the drug and diazoxide that interests us.
Taking antidepressants and analeptics lowers the effect of “Thiopental sodium.” H1-histamine-blockers and drugs that block tubular secretion (it can be, for example, probenecid) increase the effect of an anesthetic medication.
Reviews about “Thiopental sodium”
Many people agree that this tool is really effective and efficient, especially when it comes to anesthesia for the period of surgical intervention. The drug practically did not cause side effects, it was tolerated relatively easily even by children.
However, there are cases when the use of the drug caused strong side effects and negative reactions of the body to the introduction of anesthesia. It is difficult to find out what this was connected with: the negligence of doctors, the individual sensitivity of the patient, or the negative characteristics of the anesthetic itself.
Be that as it may, the use of this drug is necessary only for medical purposes and only in specialized medical resuscitation institutions.
Analogs of “Thiopental sodium”
Among the main substitutes for the medication we are interested in, it is necessary to distinguish such as Pentotal and Thiopental KMP. These funds have the same active substance and are a powder for the preparation of an injection solution. Therefore, it is not surprising that the instructions for using these medications are almost identical.