Anesthetic, General (Inhalation, Parenteral, Rectal)

General anesthetic is usually given via inhalation or injection before a procedure, but smaller doses may be used for pain management.


One of the most widely-used drugs in medical contexts, general anesthetic is usually given via inhalation or injection before a procedure. Anesthetic is commonly administered before surgery, but smaller doses may be used for pain management, labor and delivery, and in dental offices to alleviate anxiety. Anesthetics are heavily controlled due to their unpredictable and strong effects, and they should only be given by a trained doctor, dentist, or anesthesiologist.

While their effects on adults have been closely monitored and determined to be safe, some anesthetics may affect children differently in larger doses. Pediatricians and anesthesiologists are trained to know what drugs are safe for children, but no untrained individual should attempt to give anesthetic drugs to a child. Other sensitive groups include the elderly, the pregnant, and the breastfeeding.

While allergic reactions to anesthetics are not common, patients should speak to their doctors about any and all allergies they have before surgery. This includes allergies to foods, dyes, and active or inactive ingredients in medications.

Anesthetics have many interactions with a large variety of medications. Doctors will decide what dosage is appropriate or safe in cases where using both is necessary, as well as what alternatives are available.

The dose may change from case to case, depending on the situation, your current health, your sensitivity to the drugs, and your weight. Deciding a dosage can be a delicate process, especially during surgery, so it is necessary to have a trained doctor or anesthesiologist present during these situations.

Desflurane, isoflurane and sevoflurane are three of the most common inhalation-based anesthetics, which are vaporized into a anesthesia machine and given to the patient via breathing mask. This is a common mode of administration, along with injection. Injectable anesthetics include ketamine, propofol, etomidate, and a number of barbiturates.

Conditions treated

  • Unconsciousness during surgery
  • Anxiousness during dental procedures
  • Pain and anxiety during childbirth
  • Pain and anxiety in assorted medical conditions

Type of medicine

  • Inhaled or injected anesthetic

Side Effects

Side effects of anesthetics vary from person to person, depending on how much they were given and their sensitivity to the drug. As the drug leaves your system, you may experience a variety of harmless side effects. Leftover drowsiness is also common, so it is recommended that you do not attempt to walk in dangerous areas or drive until the drug's effects are completely cleared from your system.

Other common and harmless side effects include:

  • Uncontrollable shivering or trembling
  • Nausea or vomiting
  • Mild headache
  • Unusual dreams
  • Sore throat (if given anesthetics via inhalation)

These side effects are common after the administration of anesthetics, likely caused by the body trying to adjust after the drugs have worn off. They are all uncomfortable at best, but if they become serious or worrying, talk to your doctor and ask about possible solutions.

Other rarer side effects have been recorded, which may require more attention. They can vary from severe discomfort to symptoms of a larger issue, and vary from patient to patient. If you are experiencing any of these issues, whether you are still in the hospital or at home, contact your doctor immediately and consider coming in for further check-up.

  • Blood in vomit
  • Abdominal pain
  • Severe headache
  • Fever
  • Fatigue or weakness

While many people do not experience any severe side effects after being administered anesthetics, the drugs affect every person differently. If any of your side effects are concerning or severe, talk to a doctor. Otherwise, any mild side effects you experience will likely dissipate within a few hours. Most anesthetics have a short half-life, meaning they are cleared from the body quickly in comparison to other drugs or medications.


In surgical situations, the dosage of anesthetic is often determined by an anesthesiologist before surgery. Medical history is examined, and you may be asked a variety of questions so they can get a full idea of how you may react. This process is precise, and designed to avoid complications while you are on the operating table. An overdose of anesthesia may be fatal, so the dose is carefully determined to make sure that it is enough to keep a patient under, but not enough to cause toxicity.

As you go under, an anesthesiologist will monitor your progress and how you're reacting to the drug. It is not all given at the same time, and the type of anesthetic you are being given may change the dosage. Inhalation and injection may be used in tandem to get a more thorough effect. With proper dosage and administration, a patient should stay unconscious the entire time they are being operated upon.

In lighter situations, anesthetic may be used to alleviate pain and anxiety while you are still conscious. Dentists often use mild doses of anesthetic to keep their patients calm during procedures, whether routine or surgical. General anesthetics are often given via inhalation in these situations.

In a similar manner, women in labor may be given anesthetics during delivery. This alleviates anxiety and stress, but allows them to stay conscious as they give birth. These are very light doses, however, as many forms of anesthetic can be passed to the child if the mother is given too much.

Dosages are strictly determined by doctors, dentists, and anesthesiologists, as the effects can be unpredictable at times. For this reason, anesthetics are not available to the general public. The consequences of anesthetic toxicity can be fatal, causing seizures, coma, and even death.


Many doctors may ask that you avoid certain medications or drugs before your surgery, to avoid interactions during anesthetic administration. Some of these interactions can be harmless, mildly troublesome, or serious. If you are taking any drugs, prescribed or otherwise, notify your doctor a few weeks before any planned surgeries. If it is an emergency situation, make sure to carry a list of recent medications.

There are a great number of medications that may cause interaction, including heavy painkillers and antidepressants. Your doctor may ask that you lower your dose or stop treatment completely until after the surgery, or they may look to other anesthetic options to avoid any complications.

Common (more serious) interactions include, but are not limited to:

  • Firdapse® (amifampridine)
  • Solian® (amisulpride)
  • Vascor® (bepridil)
  • PROPULSID® (cisapride)
  • Multaq® (dronedarone)
  • Ephedrine
  • Serentil® (mesoridazine)
  • Orap® (pimozide)
  • Piperaquine
  • Potassium
  • Invirase® and Fortovase® (saquinavir)
  • Sparfloxacin
  • Seldane® (terfenadine)
  • Sumycin® (tetracycline)
  • Mellaril® (thioridazine)
  • Geodon® (ziprasidone)

In these situations, it is highly recommended that you mention these drugs to your doctor, especially if they are not listed in your medical history. The presence of these drugs can cause serious interactions or complications in the presence of anesthetics, so keeping them a secret is less important than your health. Even if you are taking them off-prescription, they must be mentioned.

Mild interactions may occur with other drugs, many of which are common on the market, so be sure to mention any and all drugs you might be taking, vitamins and supplements included. Your doctor may change your prescription, or lower your dose, if they believe that it may cause problems during your surgery. If the interaction is serious enough, they may ask you to go off your antidepressants or mental health medications until after the surgery.


While serious complications during the use of anesthetics are rare, they are not unheard of. Usually in these situations, the complications occur due to faulty monitoring, a patient withholding vital information, or unexpected issues. With the volatile nature of anesthetics, it is sometimes impossible to predict exactly how a patient may react to the drugs. Due to this, trained anesthesiologists are usually present to monitor them and deal with problems as soon as they arise.

In many situations where complications have occurred, the patient has been a child, an elderly individual, or a pregnant woman. These groups are more susceptible to the risks of anesthetics than most, and may require other forms of anesthetic during surgery. It is recommended that children and the elderly not be given some types of anesthetic to avoid permanent damage or sever complications.

In pediatric studies, children reacted normally to many forms of intravenous and inhaled anesthetics, but it's recommended that they are given smaller doses. Careful monitoring is also recommended, as dosing a child can be a very delicate process.

Anesthetic overdose can result in toxicity, which can seriously harm or kill anyone, especially a child. It is also recommended that anesthetics not be used religiously for clinically ill children, as it may affect the chemical balances in their body and cause complications - even death.

In pregnant women, it is recommended that they not be given certain types of anesthetics to avoid unconsciousness during labor, or drugs being passed on to the fetus. Harm can come to the fetus during pregnancy if anesthetics are used, and even newborns can become drowsy if the mother is exposed to anesthetics during surgery.

Inhalation anesthetics in particular have shown to cause harm in animal fetuses during testing, so they are to be avoided in medical contexts. Inhaled anesthetics may also slow labor and increase bleeding, which can be harmful to mothers who have just given birth.

Drugs may also be passed into breastmilk, so breastfeeding mothers should talk to their doctor if they must go into surgery. It may be necessary for the mother to stop breastfeeding for a time until the drugs have been cleared from her system.

In the elderly, increased effects have been recorded during the use and administration of anesthetics. Geriatric studies have shown that older individuals react more sensitively to anesthetics, and may react adversely to large doses in surgical situations. Increased side effects may be present, especially in the use of barbiturates. Changes have also been noted in the use of inhaled anesthetics, propofol, and etomidate. Ketamine is the only drug where no reactionary changes between adult and elderly patients have been recorded.

It is a general warning that patients being administered anesthetics avoid driving, walking in high-traffic areas, and doing dangerous tasks. Drowsiness and un-coordination may be present for up to 24 hours, which may make functioning difficult, or even dangerous. While many surgical patients should remain in the hospital regardless, people going to the dentist should have a friend or family member drive them home afterwards.

Quitting cigarettes, avoiding alcohol, and losing weight are recommended before surgery to avoid any possible complications. Serious problems are more likely if you continue doing these things, do a combination of all three, or refuse to follow your doctor's recommendations. While death on the operating table due to anesthetic-related complications is rare, many of the recorded cases involved patients who had separate issues.

While there is no guaranteed way that you will react as expected to anesthetics, having an anesthesiologist present and good health can help you. Pay attention to the warnings, trust your doctors, and do everything in your power to follow their recommendations.


As anesthetics are not passed out to the public, they are stored primarily in hospitals. Manufacturers and producers know how to handle anesthetics in both liquid and solution form, and medical staff are trained to transport, store, and use the drugs responsibly. When not in use, anesthetics are often kept in locked store rooms with the rest of the medication to prevent theft and allow for easy cataloging and inventory.

When anesthetics are necessary for a procedure or surgery, anesthesia carts are often used to sort and keep track of what anesthetics are being used. The carts can be easily moved from room to room, and may be color-coded or marked to indicate which room or wing they belong to. They are often made with locked compartments, labeled drawers for each type of anesthetic, and all of the necessary tools for administration.

They may contain a ventilator for inhalation-based anesthetics, as well as IVs and needles for intravenous modes of administration. Solutions and liquid forms of anesthetic are often kept in special containers or bottles for easy access and dosing.

The carts simplify the process of retrieving machines, needles, tubing, IVs, medication, and other tools necessary for treatment. This can be vital during emergency situations, and prevent lost time and confusion during routine procedures.

The storage guidelines for anesthetics may change depending on which drug is being used, so it is important to know exactly what a drug is before deciding on storage. Sunlight, heat, cold, and exposure to water may dilute, change, or weaken the compound and make it harmful or useless.

That being said, if you come across any form of anesthesia, turn it in to the proper authorities immediately and do not use it. It is impossible to determine dosage, storage, and safety precautions without a doctor's influence.


With anesthetics, surgeons and doctors have simplified a variety of procedures. Many complicated, dangerous surgeries can now be routinely performed without serious risk, and the comfort of the patient is now easier to achieve than ever. Many people have surgeries in their lifetime, and anesthetics make it possible for them to endure hour-long procedures while unconscious and painless.

They can be used to prevent panic on the operating table, prevent pain-responses during serious operations, and alleviate anxiety in nervous patients. Anesthetics have become one of the most widely used drugs in hospitals around the world, and while their exact method of action is still vaguely understood, they have become invaluable tools both in and out of the operating room.

Much research is still being done on their volatile effects, their toxicity to the human body, and how different kinds of anesthetic differ from each other. Their effects on children, the elderly, and pregnant individuals are also being studied, as well as new forms of anesthetic and how they can be used.

Anesthetics are not to be taken lightly, however. They are strong drugs used to subdue people's minds, and they may have unexpected effects. Allergies, sensitivities, and other factors can change how one might react to a dose of anesthetic, and heavy doses become dangerous the more is administered.

Anesthetic toxicity is deadly, and can cause a variety of issues. Seizures, coma, and death can occur if anesthesia is used irresponsibly, and proper monitoring is necessary when giving large doses. Keeping a patient under for long periods of time can also be harmful, so many doctors and anesthesiologists are trained to understand exactly how much to use and for how long.

Despite the risks and any possible complications, anesthesia can be vital to an operation. In these cases, the benefits of a painless, unconscious patient can be more important than any potential risks. Talk to your doctor honestly if you believe you may require anesthesia during any type of procedure.

Last Reviewed:
December 25, 2017
Last Updated:
April 04, 2018