Learn All about Halothane

Halothane can’t be administered to patients who have suffered from malignant hyperthermia. It’s also contraindicated in patients who are susceptible to it. Learn more about this anesthetic in this article!
Learn All about Halothane

Last update: 04 February, 2020

Halothane is a common drug medical professionals use to induce general anesthesia. It’s an anesthetic that doctors administer by inhalation to induce a rapid but smooth loss of consciousness. It has a pleasant aroma, is colorless, and doesn’t irritate the mucous membranes.

Medical professionals use it for the induction and maintenance of anesthesia in all types of surgery and in patients of all ages. However, interestingly, experts still don’t know the mechanism whereby inhalation anesthetic agents produce the inhibition of the perception of sensation and induce unconsciousness.

Medical professionals used this drug a lot during the 1950s and 1980s, both in adults and children. It was synthesized by scientific C.W. Suckling in 1951 and was first used as an anesthetic in 1956. It replaced the use of other anesthetics of the time, such as ether or cyclopropane.

However, the use of halothane reduced gradually during the 80s due to the market incorporation of new volatile anesthetic drugs, like enflurane and isoflurane. However, although it’s rarely used in developed countries, some third-world countries continue to use it in veterinarian medicine, as it’s quite inexpensive.

Dosage and administration

A patient getting oxygen through a mask.

Nowadays, different aerosol systems for the administration of halothane exist on the market. For example, there’s open circuit, semi-open, or closed-circuit systems. Medical professionals use them interchangeably because they all yield good results.

The dose will vary depending on the characteristics of the patient. In this regard, for adults and the elderly, medical professionals may administer a concentration of 2-4% halothane in oxygen/nitrous oxide to induce anesthesia. If the goal is to maintain anesthesia, the medical professional may use a concentration of 0.5-2% halothane. On the other hand, for administration in the pediatric population, a doctor may use a concentration of 1.5-2% for induction of anesthesia and a concentration of 0.5-2% for anesthesia maintenance.

Halothane contraindications

Medical professionals can’t administer this drug to patients who suffered malignant hyperthermia. Also, experts advise against its use in patients who are susceptible to it. Furthermore, if the patient develops clinical symptoms of unexplained jaundice and pyrexia after the administration of halothane, future administrations are also contraindicated.

Moreover, enough studies haven’t been conducted to assert the safety of this drug in pregnant and breastfeeding women. Therefore, it’s best to avoid general anesthesia with inhalation agents during early pregnancy. As for breastfeeding women, there aren’t enough controlled studies of halothane use in this population. However, although experts have detected the presence of this drug in breast milk, they haven’t established their effects on infants.

Moreover, people who must drive or operate machinery should take into account that general anesthesia may impair their capacity to do so. Nevertheless, despite these contraindications, medical professionals have used this anesthetic for over 30 years with no apparent consequences.

Side effects of halothane

A patient getting general anesthesia before surgery.

Halothane, like all other drugs, has possible side effects. Side effects are undesirable and unintended events that a patient may expect when they start treatment with a drug.

In this regard, halothane can trigger a skeletal muscle hypermetabolic clinical picture that ultimately may lead to malignant hyperthermia. Thus, experts advise against using it in patients who suffered from it.

Also, there are other possible side effects. Overall, these include:

  • Hypercapnia
  • Muscle stiffness
  • Tachycardia
  • Tachypnea
  • Arrhythmias

However, this drug can also cause other side effects, such as nausea, vomiting, or liver problems. As you can see, these symptoms aren’t very specific. This is why you have to pay attention. If any symptom appears, discontinue treatment immediately.


Halothane is a medication that medical professionals administer by inhalation to induce or maintain general anesthesia. If you have any questions about this medicine or general anesthesia, consult your doctor or pharmacist.

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