Halothane (Liquid) Instructions for Use

Marketing Authorization Holder

Piramal Pharma, Limited (India)

ATC Code

N01AB01 (Halothane)

Active Substance

Halothane (Rec.INN registered by WHO)

Dosage Form

Halothane

Inhalation liquid: bottle 50 ml or 250 ml

Dosage Form, Packaging, and Composition

Inhalation liquid clear, colorless, mobile, heavy, with a specific odor.

Excipients : thymol 0.01% (v/v).

50 ml – amber glass bottles (1) – cardboard packs.
250 ml – amber glass bottles (1) – cardboard packs.

Clinical-Pharmacological Group

Inhalation anesthesia preparation

Pharmacotherapeutic Group

Inhalation anesthetic drug

Pharmacological Action

An agent for inhalation anesthesia. It causes rapid induction of anesthesia without or with a minimally expressed stage of excitation. It has an analgesic and weak muscle relaxant effect. It blocks sympathetic ganglia, causing dilation of blood vessels in the skin and muscles. It increases the tone of the vagus nerve, causing bradycardia. It reduces intraocular pressure. It has a direct effect on the myocardium, reduces systolic volume and myocardial contractility, and increases myocardial sensitivity to catecholamines.

Halothane does not irritate the respiratory mucosa, does not increase saliva secretion and bronchial secretion production; it suppresses the cough and gag reflexes; proportionally to the intensity of anesthesia, it weakens uterine contractility. It does not cause acidosis. The surgical stage of anesthesia is usually reached within 4-6 minutes. After the end of anesthesia, awakening occurs within 5-15 minutes.

Depression of the respiratory center occurs at a halothane concentration in blood plasma of 30-38 mg%.

Pharmacokinetics

The blood/gas distribution coefficient is 2.3, the brain/blood distribution coefficient is 2.9, and the minimum alveolar concentration is 0.75%.

During an average duration of surgical anesthesia, 15-20% of halothane is metabolized.

Halothane is metabolized by oxidation to form trifluoroacetic acid and release bromide and chloride ions. Under low oxygen tension, Halothane is metabolized to a free radical of chlorotrifluoroethyl, which is capable of reacting with components of the hepatocyte membrane.

Elimination from the blood is slow, which causes a slow recovery from anesthesia.

Indications

Induction and maintenance anesthesia for major and minor surgical interventions in adults and children.

ICD codes

Dosage Regimen

Halothane inhalation is carried out either with oxygen or with a mixture of nitrous oxide and oxygen. For induction anesthesia, the concentration of halothane vapor in oxygen or a mixture of oxygen and nitrous oxide is usually gradually increased to 3-4 vol%. When inducing anesthesia with a non-inhalation anesthetic agent followed by the administration of a muscle relaxant, Halothane with oxygen is used only for maintenance anesthesia; the usual maintenance concentration is 0.5-2 vol%.

The surgical stage of anesthesia is usually reached within 4-6 minutes, with a halothane concentration in blood plasma of 7-12 mg%. The minimum alveolar concentration (MAC) of halothane in adults is 0.77 vol%; when 70 vol% nitrous oxide is added, it decreases to 0.3 vol%, which corresponds to levels of 16 and 6 mg% in the blood. Premedication with morphine slightly reduces the MAC of halothane. The MAC values of halothane for children under 10 years old are 0.92 vol%, for persons over 70 years old – 0.64 vol%.

Adverse Reactions

From the nervous system after awakening, headache, tremor are possible; increased intracranial pressure.

From the cardiovascular system arterial hypotension, bradycardia, cardiac arrhythmias.

From the digestive system liver function disorders up to the development of jaundice, hepatitis, liver necrosis, especially with repeated administrations; nausea is possible after awakening.

Other in some cases – malignant hyperthermia.

Contraindications

Severe liver dysfunction, history of halothane anesthesia followed by jaundice or malignant hyperthermia, increased intracranial pressure, necessity for local use of epinephrine during surgery, first trimester of pregnancy, period of childbirth, early postpartum period, for performing dental procedures outside hospital settings in children and adolescents under 18 years of age, hypersensitivity to halothane.

Use in Pregnancy and Lactation

Contraindicated for use in the first trimester of pregnancy, during childbirth, and in the early postpartum period.

In the second and third trimesters of pregnancy, use is possible for vital indications and under strict medical supervision.

After inhalation anesthesia, breastfeeding should be discontinued for 24 hours.

Use in Hepatic Impairment

Contraindicated in severe liver dysfunction.

Use in Renal Impairment

No restrictions indicated.

Pediatric Use

Contraindicated for use outside hospital settings for performing dental procedures in children and adolescents under 18 years of age.

Geriatric Use

Elderly patients require a lower dose of halothane for inhalation anesthesia, but the actual dose is based on the patient’s physical condition.

Special Precautions

Depression of the respiratory center occurs at a halothane concentration in blood plasma of 30-38 mg%.

Use with caution in patients who have received cardiac glycosides, as well as in cases of cardiac arrhythmias.

Drug Interactions

Concomitant use of sympathomimetics increases the risk of cardiac arrhythmias. It potentiates the effects of non-depolarizing muscle relaxants, bradycardia caused by digitalis preparations and cholinesterase inhibitors.

It weakens the effect of agents affecting the uterus.

Morphine and phenothiazines potentiate the depressive effect of halothane on the central nervous system.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.