How propofol works
In general, the aim of anesthesia is to eliminate pain (analgesia) and consciousness (hypnosis) for the duration of an operation. Furthermore, the muscles should relax and natural reflexes should be suppressed (vegetative attenuation). At the beginning of anesthesia, loss of consciousness is induced with a hypnotic (sleeping pill) such as propofol.
How exactly propofol develops its sleep-like effect is not fully understood. The active ingredient can switch off nerve cells for a short time and thus inhibits certain regions of the brain, namely the hippocampus, which is responsible for memory, and a region of the cerebral cortex (prefrontal cortex), which is responsible for short-term and long-term memory and the ability to make decisions. Propofol also prevents the spinal cord from transmitting signals.
Propofol is administered as an anesthetic directly into a vein (intravenously) and is therefore referred to as an injection anesthetic. Other injection anesthetics include barbiturates, etomidate and ketamine. There are also anesthetics for inhalation, known as inhalation anesthetics (such as isoflurane, sevofulran and desflurane). Injection anesthetics work faster than inhalation anesthetics and are therefore very suitable for starting anesthesia.
Absorption and excretion of propofol
This is referred to as total intravenous anesthesia. In the liver and kidneys, the active substance is quickly biochemically metabolized and broken down and then excreted. Half of it is eliminated from the body after around two hours. A small amount of propofol can also escape via the air we breathe.
When is Propofol used?
Propofol is the most commonly used intravenous anesthetic for adults and children. It is very well tolerated: patients describe falling asleep and waking up comfortably. Vomiting and nausea, which often occur after an operation, are very rare with propofol.
In anesthesia medicine, propofol is administered artificially for:
- Induction of anesthesia
- Sedation of adults during surgical procedures
- Sedation during targeted (interventional) procedures, for example during endoscopy
The active substance is also used as a treatment for epilepsy (anticonvulsant).
How propofol is used
This prevents unwanted reflexes, for example when the surgeon cuts into the skin. Even higher concentrations of propofol are required to suppress stress reactions triggered by the pain, such as an increase in blood pressure and heart rate. If the anesthetic is used in too low a dosage, the patient may regain consciousness during anesthesia.
Because propofol has no pain-relieving (analgesic) effect, an additional painkiller (analgesic) must always be administered, for example the powerful opioid fentanyl. However, a corresponding agent to relax the muscles (muscle relaxant) is also always required. The dosage is calculated based on the patient’s age and body weight as well as the duration of use.
What side effects does Propofol have?
Like any medication, Propofol can have side effects. These include
- Slowed breathing (respiratory depression) to respiratory arrest (apnea)
- Release of the messenger substance histamine and thus intolerance reactions
- Increased infections due to weakening of the immune system
Pain may occur directly at the injection site during the injection.
What should be considered when using Propofol?
Propofol is considered to be very well tolerated. Propofol can be used in newborns from the 31st day of life. However, it is only suitable for long-term sedation in intensive care units for patients older than 16 years.
It should also be noted that propofol can slow the heartbeat and lower blood pressure. Particular caution is therefore required for patients with cardiovascular insufficiency or reduced blood volume (hypovolemia).
Some substances such as the strong painkiller fentanyl or benzodiazepines can prolong and intensify the effect of propofol.
Propofol during pregnancy
The anesthetic can easily pass through the placenta to the unborn child. However, a mutagenic effect has not yet been observed. According to current knowledge, the drug does not cause any malformations (no teratogenic risk). In higher doses, however, it probably has a negative effect on the child’s circulatory system.
According to experts at the Charité hospital in Berlin, propofol can nevertheless be used throughout pregnancy in certain situations. Doctors use it, for example, to induce general anesthesia before a caesarean section.
Doctors generally only give anesthetics during pregnancy if it is necessary. It is best to tell the doctor about your concerns and ask for detailed information about the necessity and risks.
Propofol during breastfeeding
Propofol passes into breast milk in very small quantities when given to breastfeeding mothers. According to the Pharmacovigilance and Advisory Center for Embryonal Toxicology at the Charité in Berlin (embryotox), however, this does not justify an additional break in breastfeeding.
Clinical experience has so far shown no side effects in breastfed children after anesthesia of their mothers.
However, some manufacturers of the drug Propofol recommend a 24-hour break from breastfeeding. It is best to clarify this with your doctor – they can give you an individual assessment.
How to obtain medication with Propofol
Propofol is available on prescription in the form of ampoules or vials. The active ingredient is usually dissolved in an emulsion of soybean oil. The required dosage is determined and administered by a doctor.
How long has Propofol been known?
Propofol was first synthesized around 1970 and tested in a clinical study by the physicians Kay and Rolly in 1977. It was not until 1989 that it was finally approved on the market in Germany for anesthesia and in 1993 for sedation in intensive care medicine.
The drug gained sad notoriety following the death of Michael Jackson. He died of an overdose of propofol in 2009.
