Anesthetics, General (Systemic)
Before Receiving This Medicine
In deciding to use a medicine, the risks of taking the medicine must be
weighed against the good it will do. This is a decision you and your doctor
will make. For general anesthetics, the following should be considered:
Allergies - Tell your doctor if you have ever had any unusual or
allergic reaction to barbiturates or general anesthetics. Also tell your health
care professional if you are allergic to any other substances, such as foods,
preservatives, or dyes.
For barbiturate anesthetics (methohexital and
- 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.
- 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
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.
- 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.
- 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
Breast-feeding - 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.
Children - 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.
Older adults - 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
Ketamine has not been shown to cause different side effects or problems
in older people than it does in younger adults.
Other medicines - 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
general anesthetics, it is especially important that your health care professional
know if you are taking any other medicine
any of the following:
“Street” drugs, such as amphetamines (“uppers”),
barbiturates (“downers”), cocaine, marijuana, phencyclidine (PCP
or “angel dust”), and heroin or other narcotics - Serious,
possibly fatal, side effects may occur if your medical doctor or dentist gives
you an anesthetic without knowing that you have taken another medicine
Other medical problems - The presence of other medical
problems may affect the use of general anesthetics. 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