PROPOFOL

PROPOFOL:

• It is an intravenous induction agent.

• Alkyl Phenole deivative.

• First discussed in 1980.

• First used in 1960

• Became popular due to Rapid recovery & anti-emetic properties.

          Components :

• Soyabean oil : used for stability of emulsion(100mg/ml)

• Glycerol : To make emulsion isontonic

• Egg liticin :Emulsifier (12mg/ml)

• Disodium edetate : 0.005% antimicrobial effect

• Sodium hydroxide : To maintain the Ph 

Sometimes pain in injection by soyabean oil & egg liticin u can counter it by  :

• Slowing the rate of injection 
• Adding 1% Lidocaine (2ml)
• Select largest vein 

Availability :

• 200mg/20ml
• 500mg/50ml => used as TIVA for sedation in ICU.

DOSE:

• Adult : 1.5-2.5mg/kg
• Elder : 1.2mg/kg
• Child :3-3.5mg/kg
• TIVA :50-200 microgram per kg per minute
• Sedation: 50-100 microgram per kg per minute

 MECHANISM OF ACTION :

Propofol has probably the commonly used intravenous anesthetic and is most frequently used for the induction of anesthesia. Like most intravenous anesthetics, Propofol works by increasing GABA-mediated inhibatory tone in the CNS. Propofol decreases the rate of dissociation of the GABA from the receptor, thereby increasing the duration of the GABA-activated opening of the chloride channel with resulting hyperpolarization of cell membranes. At supraclinical concentrations, it may directly activate the receptor’s chloride channel.

 PHARMACOKINETIC:

IV (100% Bioavailability)
Lipid soluble

 DISTRIBUTION:

• Lipid soluble
• 80-95% attached to plasma protein
• Non-iodized form lost during acidosis
• Blood supply to the organs

BIO-TRANSFORMATION:

• Hepatic metabolism

• Extra hepatic metablism

• 3-4 hr duration half-life

• Less then 60 mins for action

• No side effect of its metabolite 

• It is safe drug in liver disease 

 EXCRETION:

It is excreted because its metabolites are water soluble so that why it is excreted through Renal way.

PHARMACODYNAMICS:

• Action on CNS : onset of action => 20-40sec

• It is slow then thiopental because it suppress CVS so it take time to reach brain .

• Duration of action : 2-10 mins

• Plasma terminal half life : 3-4hrs

• Terminal half life : less then 60 mins

• Eyelash reflexes disappears take more time then thiopental 

• Induction : not smooth

• Recovery :smooth

• Muscle twitching during induction

• Hiccup

• Tonic -clonic seizures  

• Decreased CBF 

• Decreased ICP

EFFECT ON CVS:

• SVR Decreased

• Cardiac input Decreased

• Cardiac output Decreased

• Bradycardia

• Premedication :

• Anticholinergic (Atropine)

EFFECT ON RESPIRATORY:

• Respiratory Rate decreased

• Tidal volume decreased

• Respiratory drive decreased

EFFECTS ON UTERUS & PLACENTA:

• Decrease uteric blood flow

• Decrease uterine tone(safe for pregnant woman)

EFFECTS ON HEPATIC & RENAL :

• Blood flow decreases(safe in liver disease)

• GFR decreases no affect on drug excretion (safe in renal disease)

 INDICATION:

• General anesthesia

• Induction

• TIVA

• Sedation in ICU

• Use in day care surgery

• Short procedure

• Used in propyria

CONTRAINDICATED:

• Neonate -> below 1 year

• Hypersensitivity reaction

• Cardiac disease like CHF

• Hypovolumia

SIDE EFFECTS:

• Apnea

• CVS depression

• Respiratory depression

• Pain injection

• Hypersensitivity reaction

• Propofol infusion syndrome

REFERENCE:

https://www.elsevier.ca/ca/product.jsp?isbn=9780702041921