Halothane 

Enflurane

Isoflurane

CVS

Decreased BP, decreased heart rate (bradycardia) Arrhythmias may be precipitated due to sensitization of the myocardium to the effects of catecholamines.   

No sensitization of the myocardium. Causes less suppression than halothane. 

Less suppression than halothane & enflurane. No sensitization of the myocardium.

CNS

Fast SM induction without Stadium II. Increased cerebral blood flow & increased intracranial pressure (so be careful in pts with head injuries). Repeated exposure increases the risk for liver damage (allow 3mnths between exposures). 

Fast SM induction. May cause convulsions thus not used in pts with epilepsy. 

Faster induction & recovery than halothane. 

RENAL

Reduce glomerular filtration rate and urine output. Contraindicated in pts with renal impairment.  

Reduce glomerular filtration rate and urine output. Contraindicated in pts with renal impairment.  

Reduce glomerular filtration rate and urine output. Contraindicated in pts with renal impairment.  

HEPAT

The extent of metabolism is 20-25%. Although rare, hepatotoxicity can occur since the drug is metabolized in the liver (so be careful in pts with liver problems)

Only 2-5% is metabolized by the liver. 

UTER

Decreased muscle contraction, it is also used to promote external twisting if the baby is lying incorrectly

Widely used in caesarean sections. 

RESP

No irritations (saliva, bronchial secretions, coughing)

More depression than halothane. 

Potent depressing effect due to potent skeletal muscle relaxing effects (so be careful in pts with asthma). 

USE

Not often used because of hepatotoxicity. The newer drugs are safer & rather used. 

Not often used. Used in maintenance of anesthesia. 

More ideal than halothane & Enflurane. Widely used but not for patients who have to breath spontaneously. 

Desflurane 

Sevoflurane 

Nitrous Oxide 

CVS

Less suppression than halothane and enflurane. 

Similar effects to desflurane. 

No effect. 

CNS

Even faster induction & recovery than isoflurane. Increased cerebral blood flow & intracranial pressure. 

Similar effects to desflurane.

Weak anesthetic, potent analgesic & may cause amnesia as a side effect. 

RENAL 

Reduce glomerular filtration rate and urine output. Contraindicated in pts with renal impairment.  

Reduce glomerular filtration rate and urine output. Contraindicated in pts with renal impairment.  

Reduce glomerular filtration rate and urine output. Contraindicated in pts with renal impairment.  

HEPAT

Undergoes liver metabolism & chemically unstable (be careful in pts with reduced/ compromised liver function)

Undergoes liver metabolism so must be used with caution in pts with liver problems. 

UTER

Not recommended for obstetric operations. 

Can be used in caesarean sections.

RESP

Strong smell which irritates airways. Can’t be used as induction drug since it causes coughing, shortness of breath, laryngospasm. 

Less irritation of the airways. 

Pure N₂O will lead to hypoxia so it must be mixed with O₂or air. 

USE

More ideal than isoflurane & sevoflurane. Can be used for various surgical procedures. 

Used for induction & maintenance. 

Used as additive drug in anesthesia or as single drug for short dental procedures.