Indications & Uses
Terrell can be given to induce and maintain general anesthesia. There isn't enough evidence yet to support its use in obstetric (childbirth-related) anesthesia.
Dosage Reference
Reference Information Only
Dosages shown are general references from official sources. Always consult your doctor or pharmacist for personalized dosing.
Adults:
Route of administration: Isoflurane should be given by inhalation, delivered from a vaporizer designed specifically for use with isoflurane, and only by persons trained in administering general anesthesia. Facilities for maintaining a patent airway, providing artificial ventilation, enriching oxygen, and supporting circulatory resuscitation must be immediately available. The minimum alveolar concentration (MAC) of isoflurane decreases as the patient's age increases. Premedication: Premedication should be chosen according to the individual patient's needs, bearing in mind that isoflurane only weakly stimulates secretions and tends to increase heart rate. Induction: Inducing anesthesia with isoflurane in oxygen, or in combination with oxygen nitrous oxide mixtures, may cause coughing, breath holding, laryngospasm and bronchospasm, and these effects increase with the concentration of isoflurane used. Giving a hypnotic dose of an ultra short acting barbiturate can help avoid these difficulties. Inspired concentrations of 1.5 to 3.0% isoflurane usually produce surgical anesthesia within 7 to 10 minutes. Surgical levels of anesthesia can be maintained with a concentration of 1.0 to 2.5% when nitrous oxide is used alongside isoflurane. An additional 0.5 to 1.0% may be needed when isoflurane is given with oxygen alone. If further muscle relaxation is needed, supplemental doses of muscle relaxants may be used. During maintenance, blood pressure tends to fall as the isoflurane concentration rises, provided no other complications are present. Excessive drops in blood pressure may result from anesthesia being too deep, and in such cases can be corrected by lightening the anesthesia.
Side Effects
The most common side effects include delirium, agitation, breath holding, cough, laryngospasm, nausea, vomiting, chills/shivering and nodal arrhythmia.
Cautions & Contraindications
Warnings & Precautions
Use of inhaled anesthetic agents has been associated with rare increases in serum potassium levels that have resulted in cardiac arrhythmias and death in pediatric patients during the postoperative period. In susceptible individuals, may trigger malignant hyperthermia, a skeletal muscle hypermetabolic state leading to high oxygen demand. If malignant hyperthermia is suspected, discontinue all triggering agents, administer intravenous dantrolene sodium and initiate supportive therapies. Cases of mild, moderate and severe postoperative hepatic dysfunction or hepatitis with or without jaundice, including fatal hepatic necrosis and hepatic failure, have been reported with Terrell. QTc prolongation, with rare instances of torsade de pointes, have been reported. Monitor QT interval when administering Terrell to susceptible patients. All patients anesthetized with Terrell should be continually monitored. Respiration should be closely monitored and assisted or controlled ventilation employed when necessary. Maintenance of normal hemodynamics is important to the avoidance of myocardial ischemia in patients with coronary artery disease. Consider additional cardiac monitoring in patients with known coronary artery disease, as clinically necessary. Particular care must be taken when selecting the dosage for patients who are hypovolemic, hypotensive or otherwise hemodynamically compromised, e.g., due to concomitant medications. In patients with or at risk for elevations of intracranial pressure (ICP), administer Terrell in conjunction with ICP reducing strategies, as clinically appropriate. When a clinician suspects that CO2 absorbent may be desiccated, it should be replaced before the administration of Terrell. Terrell, as well as other general anesthetics, may cause a slight decrease in intellectual function for 2 or 3 days following anesthesia.
Contraindications
Isoflurane should not be used in anyone who is hypersensitive to isoflurane, to other halogenated anesthetic agents, or to any other ingredient in the product, or in anyone for whom general anesthesia itself is contraindicated. It should also be avoided in patients with a known or suspected genetic susceptibility to malignant hyperthermia, and in those with a history of confirmed hepatitis linked to a halogenated inhalational anesthetic, or a history of unexplained moderate-to-severe liver dysfunction (such as jaundice accompanied by fever and/or eosinophilia) following anesthesia with isoflurane or another halogenated inhalational anesthetic.