Drug information of Isoflurane

Mechanism of effect

Isoflurane induces a reduction in junctional conductance by decreasing gap junction channel opening times and increasing gap junction channel closing times.
Isoflurane also activates calcium dependent ATPase in the sarcoplasmic reticulum by increasing the fluidity of the lipid membrane. Also appears to bind the D subunit of ATP synthase and NADH dehydogenase .
Isoflurane also binds to the GABA receptor, the large conductance Ca2+ activated potassium channel, the glutamate receptor and the glycine receptor.

Pharmacodynamic

Isoflurane is a general inhalation anesthetic used for induction and maintenance of general anesthesia. It induces muscle relaxation and reduces pains sensitivity by altering tissue excitability.
It does so by decreasing the extent of gap junction mediated cell-cell coupling and altering the activity of the channels that underlie the action potential.

Pharmacokinetics

Isoflurane undergoes minimal biotransformation in man. In the postanesthesia period, only 0.17% of the Isoflurane taken up can be recovered as urinary metabolites.
Onset : Rapid (7-10 min)
Duration : Short (depends on blood concentration)
Minimum Alveolar Conc : 1.3%
Metabolism : Liver (0.2%)

Dosage

Anesthesia Induction & Maintenance
Use calibrated vaporizer
Induction : 1.5-3% can produce surgical anesthesia in 7-10 minutes
Maintenance : 1-2.5% with nitrous oxide
Additional 0.5-1% may be needed if given with oxygen alone.

Drug contraindications

hypersensitivity to this drug

Side effects

nausea , Dyspnea

Interactions

Expectorant , Epinephrine , Phenytoin , Levodopa , fentanyl , Vecuronium , Pancuronium , Norepinephrine , Diethylpropion , Mefloquine , lisdexamfetamine , Rocuronium , Xylometazoline , Propylhexedrine , acrivastine+pseudoephedrine , Acetaminophen and benzhydrocodone

Alerts

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 .
Patient with latent as well as overt neuromuscular disease, particularly Duchenne muscular dystrophy, appear to be most vulnerable. Concomitant use of succinylcholine has been associated with most, but not all, of these cases.
In susceptible individuals, Isoflurane anesthesia may trigger a skeletal muscle hypermetabolic state leading to high oxygen demand and the clinical syndrome known as malignant hyperthermia.
The syndrome includes nonspecific features such as muscle rigidity, tachycardia, tachypnea, cyanosis, arrhythmias, and unstable blood pressure.
Isoflurane markedly increases cerebral blood flow at deeper levels of anesthesia. There may be a transient rise in cerebral spinal fluid pressure, which is fully reversible with hyperventilation.

Points of recommendation

Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
Isoflurane , as well as other general anesthetics, may cause a slight decrease in intellectual function for 2 or 3 days following anesthesia. As with other anesthetics, small changes in moods and symptoms may persist for up to 6 days after administration.

Pregnancy level

C

Related drugs

Sevoflurane , Desflurane , Nitric oxide , Ketamine , Enflurane , Methohexital , Nitrous oxide