Anesthetic, General (Inhalation Route, Parenteral Route, Rectal Route)
Original Article: http://www.mayoclinic.com/health/drug-information/DR602243
US Brand Names
Canadian Brand Names
General anesthetics normally are used to produce loss of consciousness before and during surgery. However, for obstetrics (labor and delivery) or certain minor procedures, an anesthetic may be given in small amounts to relieve anxiety or pain without causing unconsciousness. Some of the anesthetics may be used for certain procedures in a medical doctor's or dentist's office.
Propofol is used sometimes in patients in intensive care units in hospitals to cause unconsciousness. This may allow the patients to withstand the stress of being in the intensive care unit and help the patients cooperate when a machine must be used to assist with breathing. However, propofol should not be used in children in intensive care units.
Thiopental also is sometimes used to control convulsions (seizures) caused by certain medicines or seizure disorders. Thiopental may be used to reduce pressure on the brain in certain conditions. Thiopental also is used to help treat some mental disorders. Thiopental may also be used for other conditions as determined by your doctor.
General anesthetics are usually given by inhalation or by injection into a vein. However, certain anesthetics may be given rectally to help produce sleep before surgery or certain other procedures. Although most general anesthetics can be used by themselves in producing loss of consciousness, some are often used together. This allows for more effective anesthesia in certain patients.
General anesthetics are given only by or under the immediate supervision of a medical doctor or dentist trained to use them. If you will be receiving a general anesthetic during surgery, your doctor or anesthesiologist will give you the medicine and closely follow your progress.
Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, ketamine and thiopental are used in certain patients with the following medical conditions:
- Anesthesia in children (ketamine)
- Hypoxia, cerebral (shortage of oxygen supplied to the brain) (thiopental)
- Ischemia, cerebral (shortage of blood supplied to the brain) (thiopental)
- Sedation in children (ketamine)
This product is available in the following dosage forms:
Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Anesthetics given by inhalation and ketamine have been tested in children and have not been shown to cause different side effects or problems in children than they do in adults.
Although there is no specific information comparing use of etomidate in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in adults.
Although there is no specific information comparing use of thiopental administered intravenously in children with use in other age groups, using thiopental intravenously in children is not expected to cause different side effects or problems in children than it does in adults.
Propofol has been tested in children to produce loss of consciousness before and during surgery. It has not been shown to cause different side effects or problems in children than it does in adults. Propofol should not be used in critically ill children to help the children withstand the stress of being in the intensive care unit. Some critically ill children have developed problems with their body chemistries after receiving propofol, and a few children have died as a result of this. It is not known if propofol or the severe illnesses of the children caused this problem.
Elderly people are especially sensitive to the effects of the barbiturate anesthetics (methohexital and thiopental), etomidate, propofol, and anesthetics given by inhalation. This may increase the chance of side effects
Ketamine has not been shown to cause different side effects or problems in older people than it does in younger adults.
- For barbiturate anesthetics (methohexital and thiopental)—Methohexital has not been studied in pregnant women. However, it has not been shown to cause birth defects or other problems in animal studies. Studies on effects in pregnancy with thiopental have not been done in either humans or animals. However, use of barbiturate anesthetics during pregnancy may affect the nervous system in the fetus.
- For etomidate—Etomidate has not been studied in pregnant women. Although studies in animals have not shown etomidate to cause birth defects, it has been shown to cause other unwanted effects in the animal fetus when given in doses usually many times the human dose.
- For inhalation anesthetics (enflurane, halothane, isoflurane, methoxyflurane, and nitrous oxide)—Enflurane, halothane, isoflurane, methoxyflurane, and nitrous oxide have not been studied in pregnant women. However, studies in animals have shown that inhalation anesthetics may cause birth defects or other harm to the fetus. When used as an anesthetic for an abortion, enflurane, halothane, or isoflurane may cause increased bleeding. When used in small doses to relieve pain during labor and delivery, halothane may slow delivery and increase bleeding in the mother after the baby is born. These effects do not occur with small doses of enflurane, isoflurane, or methoxyflurane. However, they may occur with large doses of these anesthetics.
- For ketamine—Ketamine has not been studied in pregnant women. Studies in animals have not shown that ketamine causes birth defects, but it has caused damage to certain tissues when given in large amounts for a long period of time.
- For propofol—Propofol has not been studied in pregnant women. Although studies in animals have not shown propofol to cause birth defects, it has been shown to cause deaths in nursing mothers and their offspring when given in doses usually many times the human dose.
General anesthetics may cause unwanted effects, such as drowsiness, in the newborn baby if large amounts are given to the mother during labor and delivery.
Barbiturate anesthetics (methohexital and thiopental), halothane, and propofol pass into the breast milk. However, general anesthetics have not been reported to cause problems in nursing babies.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving any of the medicines in this class, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.
Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Arsenic Trioxide
- Chloral Hydrate
- Nitrous Oxide
- St John's Wort
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other Medical Problems
The presence of other medical problems may affect the use of medicines in this class. Make sure you tell your doctor if you have any other medical problems, especially:
- Malignant hyperthermia, during or shortly after receiving an anesthetic (history of, or family history of). Signs of malignant hyperthermia include very high fever, fast and irregular heartbeat, muscle spasms or tightness, and breathing problems—This side effect may occur again.
The dose medicines in this class will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
The dose of a general anesthetic will be different for different patients. Your doctor will decide on the right amount for you. The dose will depend on:
- Your age;
- Your general physical condition;
- The kind of surgery or other procedure you are having; and
- Other medicines you are taking or will receive before and during surgery.
For patients going home within 24 hours after receiving a general anesthetic:
- General anesthetics may cause you to feel drowsy, tired, or weak for up to a few days after they have been given. They may also cause problems with coordination and your ability to think. Therefore, for at least 24 hours (or longer if necessary) after receiving a general anesthetic, do not drive, use machines, or do anything else that could be dangerous if you are not alert.
- Unless otherwise directed by your medical doctor or dentist, do not drink alcoholic beverages or take other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness) for about 24 hours after you have received a general anesthetic. To do so may add to the effects of the anesthetic. Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; other sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; other barbiturates; medicine for seizures; and muscle relaxants.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:Rare
- Abdominal or stomach pain
- Back or leg pain
- Black or bloody vomit
- Headache (severe)
- Increase or decrease in amount of urine
- Loss of appetite
- Nausea (severe)
- Pale skin
- Unusual tiredness or weakness
- Weakness of wrist and fingers
- Weight loss (unusual)
- Yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:More common
- Shivering or trembling
- Blurred or double vision or other vision problems
- Dizziness, lightheadedness, or feeling faint
- Mood or mental changes
- Nausea (mild) or vomiting
- Nightmares or unusual dreams
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.