Halothane has hepatotoxicity, as it is converted into free radicals, initiators of lipid peroxidation, in the liver, and also forms metabolites (fluoroethanol) that covalently bind to biomacromolecules. The incidence of hepatitis is 1 case per 10 000 anesthesia in adult patients. In children, liver damage develops much more rarely.
It causes muscle relaxation, so it should be used with caution in patients with myasthenia gravis and / or with simultaneous use with aminoglycoside antibiotics.
During anesthesia, there may be an increase in blood flow in the vessels of the brain and / or an increaseintracranial pressure. These effects are usually more pronounced in the presence of intracranial neoplasms. To counteract these effects in neurosurgery, moderate hyperventilation is used.
There is a risk of arrhythmias in children.
Use with caution when taking cardiac glycosides.
Treatment with MAO inhibitors should be discontinued 2 weeks before surgery.
It is necessary to cancel levodopa 6-8 hours before the start of general anesthesia.
When gynecological operations should be taken into account that halothane can cause a decrease in the tone of the myometrium and, as a consequence, an increased risk of bleeding.
Halothane relaxes the myometrium, so it is used in obstetric practice only in cases when the relaxation of the uterus is indicated.
Patients with chronic alcoholism for anesthesia require large doses.
The possibility of developing malignant hyperthermia should be remembered with insufficient muscle relaxation at the beginning of anesthesia, as well as in the occurrence of fasciculations in response to the introduction of ditiline (suxamethonium).
The monitoring of the patient's condition in anesthesia is carried out by monitoring the pulse, blood pressure (measured manually or automatically,direct and indirect methods), continuous ECG recording, oxygen content in the blood (observing the color of the skin and mucous membranes, using a pulse oximeter or a blood test), body temperature, pupil response, diuresis rate, blood gas analysis, electrolyte composition and acid -basic state.
Do not store in evaporators; before the new use, the evaporator must be cleaned of the halotane residues and the products of its decomposition. Timol (used for stabilization) does not evaporate, remains in the evaporator, staining the solution in a yellowish color, it is readily soluble, eliminated by ether.