Anaesthetics

Bupivacaine (Amides group).

• Also called as numbing medicine.
• FDA approved drug for use in veterinary medicine.

MOA:

• Bupivacaine binds voltage gated Na channel and inhibits depolarisation. The nerve membrane gets  stabilized and remains in phase 0 depolarisation.

Effects:

• Neurotransmission is blocked.
•  Loss of pain sensation.
•  Numbness.

Side effects:

•  Arrhythmia.
•  Reduced cardiac output.

Species :  

• Dog,Cat, Horse, Sheep , Goat, Cattle and Pig.

Dose:

• 1-3mg /kg (0.25%-0.75%)S/c. 

Indication: 

• Local and regional anesthesia
• Post operative pain.

Contraindication:

• Never use IV as it is cardio toxic.
• Never use in abscess.
• Don’t use as topical or surface anaesthetic.
•  Haemorrhagic shock.

Brands:

Available as Human brands in India :

• Anawin 20ml inj vial ( Neon Labs India).

Composition: Each ml contains 0.5% bupivacaine.

• Bupivan 20 ml inj vial( Sun India).

Composition: Each ml contains 0.25% bupivacaine.

• Marcain 20 ml inj vial( AHPL India).

Composition: Each ml contains 0.5% bupivacaine.

• Bupivacaine 20ml inj vial ( ICI India).

Composition: Each ml contains 0.25% bupivacaine.

• Zupivac -PF 20ml inj vial (Flagship Biotech International Private Limited India).

Composition: 0.5% W/V Bupivacaine.

• Bupiwell 20ml inj vial ( Wellona Pharma India).

Composition:0.5% W/V Bupivacaine.

Detomidine(imidazole derivative).

• High therapeutic index.

MOA: 

• Detomidine  activates  α2 catecholamine receptors.
• Activated α2 catecholamine receptors induce negative feedback response, reducing production of excitatory neurotransmitters.

Effects :

• Sedation and analgesia.

The depth and duration of sedation and Analgesia are dose dependent.

Side effects:

•  Muscular twitching.
•  Sweating.
•  Piloerection.
•  Hyperglycaemia.
•  Marked diuresis. 
•  Reduced gut motility. 

Side effects increase in frequency and duration with increased dose

Species:

• Horse and Cattle.

Drug Combinations:

• Detomidine 0.02 mg/kg+Butorphanol 0.05 mg/kg+Acepromazine 0.03 mg/kg in same syringe IM  for heavy sedation.

Dose:

• 20mcg/kg or 40mcg IM/ IV/ sublingual  depending upon depth and duration of Sedation and Analgesia.
• Similar dose for cattle.

Standing Sedation/Analgesia Protocols using Detomidine alone.

 8.4 µg/kg IV loading dose, followed by 0.5 µg/kg per minute. 

Protocol:

Add 5 mL of 10 mg/mL detomidine to a 500-mL N.S 

  Administer @0.005 drops/kg per second. The rate can be adjusted as needed to maintain effective sedation.

Indication:

•   Primarily as a sedative.
•  Anaesthetic adjunct.
•  Analgesia.
•  Colic in horses.

Contraindication:

•  Pre-existing heart diseases.
•  Respiratory diseases.
•  Renal and hepatic insufficiency.
•  Concurrent use of sulpha drugs.

Brands: 

•  Dormosedan 5ml/20ml injection ( Pfizer USA).

Composition: Each ml contains 10mg Detomidine. 

• Detomidine hcl 10ml inj ( Nex Gen India)

Composition: Each ml contains 20mg Detomidine.

Atipamezole (Alfa 2 antagonists).

• Acts as reversal agent for alfa 2 sedatives in animals.

MOA:

• Atipamezole is alfa 2 antagonist. It competes with Medetomidine , Dexmedetomidine and Xylazine .
•  It  displaces them from receptors.

Effects:

• Reverse the sedative effects of alfa 2 agonists.

Side effects:

• Vomiting and Diarrhea.
•  Hypersalivation. 
• A brief period of excitation or apprehensiveness and tremors 

Species : 

• Cats , Dogs, Cattle , Rabbits and Horses.

Dose:

• 0.05-0.4mg/kg IM.

 5 mg atipamezole reverses the effects of I mg medetomidine and 0.5 mg dexmedetomidine.

Indication:

•  To reverse the effects of Metomedomidone, Dexmedetomidone and Xylazine.
• To reverse the toxic effects of Amitraz.
• To reverse the cardiovascular depression caused by alfa 2 agonists.
• To reverse the hypotensive effects of Tizanidine.
• To reverse toxic effects of decongestant like Ephedrine and Pseudoephedrine.

Contraindication:

• No absolute contraindication , but should not be immediately used when Dexmedetomidone is given with ketamine.
• It should also be avoided in pregnant animals, lactating animals and animals sedated for breeding.

Brands:

• Antisedan 10ml inj viall( Zoetis USA) offered by Jubilant Life Sciences India.

Composition: Each ml contains 5mg Atipamezole.

Glycopyrrolate(Quaternary Ammonium Compound).

• Approved for dogs and cats.

MOA:

• Glycopyrrolate  competitively antagonizing acetylcholine at postganglionic muscarinic cholinergic receptors in the parasympathetic nervous system.
• Glycopyrrolate is not selective in binding to muscarinic receptor subtypes.

Effects:

• Reduction in secretions, increase in heart rate and  pupil dilation.

Side effects:

• Tachycardia, dry mouth, straining during urination, constipation, or vomiting.

Species: 

• Dog and  Cat.

Dose: 

• 10mcg/kg IV/ IM/ SC .

Indication:

•  To treat and/or prevent anaesthetic and preanesthetic bradycardia.
•  To decrease airway and salivary secretions.
•  To dilate the pupil.
•  To block vagally mediated reflexes (viscerovagal, oculocardiac, Branham).
•  To block the effects of parasympathomimetic drugs.

Contraindication:

• Asthma.
•  Heart block and heart failure.
•  Slow heart rate.
•  Shock.
•  Allergy to drug.

  Use cautiously in prostate enlargement, liver and kidney disease, thyroid problem, GIT infection, and oesophageal reflux.

Brands:

•  Amtech Glycopyrrolate Injectable 20 mL(Teva Animal Health USA).

Composition: Each mL contains 0.2mg Glycopyrrolate.

Brands:

Human brands in India.

• Pyrolate 1ml ampule( Neon  India).

Composition: Each mL contains 0.2mg Glycopyrrolate.

• Glycogem 1ml ampule ( Haterd Health Care India).

Composition: Each mL contains 200mcg Glycopyrrolate.

• Glypro 1 ml ampule( Aeromatic India).

Composition: Each mL contains 0.2mg Glycopyrrolate.

• Glycolate 1ml ampule ( Nex Gen India).

Composition: Each mL contains 0.2mg Glycopyrrolate.

Ketamine(Dissociative anaesthetics).

• Date rape drug.
•  Fast-acting anaesthetic and painkiller commonly used in  veterinary surgery 

MOA:

• Ketamine blocks NMDA receptors in spinal cord thereby disrupts pain perception.
• Disrupts glutamate (responsible for perception of pain , emotions, learning and memory) in CNS.
• At higher dose also block mu and sigma receptors.

Effects: 

•  Dissociation from environment.
•  Decreased response to painful stimulus.

Side effects:

•  Muscle spasms.
•  Amnesia.
• Increase heart rate.
•  Catalepsy and convulsive aggression.

Species:

• Nearly all kinds of animals.

Drug combinations:

•  Ketamine+ Xylazine+ Diazepam.
•  Ketamine+ Xylazine+ Medazolam.
•  Ketamine+ Xylazine+ Romifidine.
•  Ketamine+ Xylazine+ Guaifenesin.
•  Ketamine+ Acepromazine.
•  Ketamine+ Xylazine.
•   Ketamine+ Propofol.

Effects of combinations;

•  Muscle relaxation and to counter cataleptic effects of ketamine.
•  Uneventful recovery.
•  Potentiate anaesthetic effect of ketamine.
•  Sedation of animal and to increase the duration of anaesthesia.

Dose:

• 2.2 mg/kg IV in horse.
• 2mg/kg IV  in bovines.
• 10mg/kg IM  in sheep and goat.
• 10-20mg)kg IV in pig.
• 25-60 mg/kg IM or SC in swine.
• 5-10 mg/kg IV or IM in rabbit.
• 5mg-10mg/kg IV or IM in dog and cat.
• 15-40 mg/kg IM in non-domesticated species.

Indications:

•  Anaesthesia in animals.
•  Chemical restraint.
•  Restraint of fractious animals by mouth spraying of ketamine.
•  As part of total intravenous anaesthesia( TIVA).

Contraindication:

•  Hepatic and Renal insufficiency.
•   Hypertension.
•   Head trauma.
•  Not good as sole anaesthetic agent.
•   Avoid use in pharyngeal and laryngeal surgical procedures.

Brands:

Available as human brands in India.

•  Aneket 5ml /10ml /20ml vial (Neon Laboratories India).

Composition: Each ml contains 10mg Ketamine.

•  Ketalar 10ml injection (JHP Pharmaceutical India).

Composition: Each ml contains 50mg Ketamine.

• Hypnoket 10ml vial ( Chndra Bhagat Pharma India).

Composition: Each ml contains 50mg Ketamine.

• Keta 10ml Vial ( Samarth India).

Composition: Each ml contains 50mg Ketamine.

• Ketafast 10ml vial( Taj Pharma India).

Composition: Each ml contains 50mg Ketamine

Medetomidine( pyrazole derivative).

• Racemic mixture of dexmedetomidine and levomedetomidine.
• Dexmedetomidine is active component.

MOA:

• Medetomidine is potent and the most specific α2- receptor agonist.
• Inhibits dose dependent release and turnover of noradrenaline in the central nervous system.
•  Medetomidine causes vasoconstriction by activation of postsynaptic receptors in the vascular smooth muscle.

Effects:

•  Sedation and analgesia. 

Side effects:

• Bradycardia. 
•  Initial increase in ABP due to an increase in systemic vascular resistance followed by hypotension.
• Vomiting.
•  Cyanosis of mucous membranes due to vasoconstriction.
  Keep fasting for at least 12 hrs before administration of the drug.

Species: 

• Dog , Rabbit and wild animals.

Drug Combinations:

• Medetomidine+ Ketamine for anaesthesia.

Dose:

• Dose is given as per body surface area.
• Young Dogs require more dose than adult dogs.
• 750mcg/sqm IV or 1000mcg /sqm IM.

Indication:

• For sedation and analgesia.
• As adjunct to anaesthesia.

Contraindication:

• Cardiac and respiratory diseases.
•  Renal and hepatic insufficiency.
•  Stress fatigue and Debilitation.
•  Shock.

Brands:

•  Domitor 10ml injection ( Pfizer USA).

Composition: Each ml contains 1mg Medetomidine.

• Domitor 10ml injection ( Vetoquinol UK).

Composition: Each ml contains 1mg Medetomidine.
Medetomidine10ml inj vial( Next-Gen USA).

Composition: Each ml contains 10mg Medetomidine.


 

Propofol( alkyl phenol derivative i.e 2, 6 di-isopropyl phenol).

• Called as milk of amnesia.
• Anaesthetic drug that produces:

1. Rapid induction
2. Satisfactory sedation with good haemodynamic stability.
3.  Fast and unexcited recovery .

MOA:

• Propofol potentiates the activity of the gama amino butyric acid (GABA) receptor and  activate the GABA receptor- chloride ionophore complex.

Effects:

• Amnesic effect.
• Sedation.
• Anaesthetic effect.

Side effects:

• Hypotension.
• Transient apnea.
• Vasodilation.
• Convulsions.

Species:

• Dog, cat, sheep , goat,  camel and horse.

Drug combination:

• Propofol + acetyl promazine( Dogs).
•  Propofol + diazepam( Dogs).
• Propofol + diazepam-ketamine (Dogs) .
• Propofol+ xylazine( Camels).
• Propofol+ medetomidine / detomidine ( Equines) .
• Propofol +detomidine-guaifenesin ( Equines).
• Propofol + thiopentone ( Dogs).
• Propofol + isoflurane/halothane ( Dogs).

Dose:

• 5.5mg/kg IV for induction in dogs.
• 2.2mg/kg IV for maintenance in dogs.
• 2.0 mg/kg IV for induction in horses.
• 0.2mg /Kg IV for maintenance in horses.
• 5.1 mg/kg IV for induction in goats.

Indication:

• As anaesthesia for short procedures (5-10 min)  
•  As sedative.
• As hypnotic.

Contraindication:

• Use cautiously in hypovolemia.
• Use cautiously in cardiac and respiratory problems.
• Use cautiously in lipid metabolism disorder.
•  Consecutive use of propofol in cats  leads to anorexia, lethargy and diarrhea.

Brands : 

• PropoFlo 20 ml inj vial ( Zoetis USA).

Composition: Each ml contains 10 mg propofol .

• Rapanofal 20 ml inj vial ( Ivaoes Animal Health  USA).

Composition: Each ml contains 10 mg propofol .

Human brands:

• Neorof 10ml inj vial ( Neon India).
  Composition: 1%w/v propofol.
• Cenofol 20ml  inj vial ( Centurion India).
   Composition: 1%w/v propofol.
• Pofol 50 ml inj vial ( Baxter India).

Composition: 1%w/v propofol.

• Diprivan 20 ml inj vial ( AHPL India).
  Composition: Each ml contains 10 mg propofol.
  
  
  
  

Romifidine( α2 agonist).

• Parent chemical for  Romifidine is Aniline and substituted Aniline.
• Belongs to chemical class of xylazine, medetomidine, Clonidine family.
• Developed from Clonidine.
• Approved for horses as sedative , preanesthetic, and analgesic drug.
• Sedation without ataxia and wobbling  makes it  popular drug in horses 
•  Drug is much more costlier than xylazine so commonly not available. 

MOA:

• Romifidine is α2 adrenergic receptor agonist.
• The ratio of  α1 to α2 affinity is 1:360 which is twice that of Xylazine. 
• Binding with presynaptic α2 adrenergic receptors( subtypes) leads to decrease in neurotransmitters thereby reduces sympathetic neurotransmission.

Effects:

• Sedation and analgesia.

Side effects:

• Bradycardia 
• Respiratory depression.
• Reduced GIT motility.

Drug combination:

• Romifidine+Ketamine+ Diazepam( Anaesthetic combination).
• Romifidine+Butorphanol( analgesic combination).
  Antidote:
• Yohimbine for reversal of Romifidine effects and side effects.

Species:

• Horse.
• Can also be used in Dogs.

Dose:

• For Sedation and analgesia:
  0.04-0.120 mg/kg slow I.V.
• As preanesthetic:
  0.1mg/kg slow I.V.
• Combination anaesthesia:
  Romifidine(100 μg/kg IV) , Diazepam(0.04 mg/kg  IV)+ Ketamine (2.2 mg/kg IV).
• Romifidine is given 3 to 5 minutes prior to  ketamine -diazepam drug combination.

Indication:

•  Physical examination of aggressive horses.
•  Radiographic examination of horse.
• Minor Surgical procedures like draining abscess , castration etc in standing horses.
• As preanesthetic.
• As analgesic.
• As component of drug combinations used in anaesthesia protocol in horses.

Contraindication:

• Horses suffering cardiac arrhythmias.
• Heaves.
• Avoid to use in horses who are on  trimethoprim sulpha  drugs and chloramphenicol .
• Kidney and liver problems.
• Hypovolemia and shock.

Brands:

• Rominervin 20ml inj vial ( Dechra UK).

Composition: Each ml contains 10mg Romifidine.

• Sedivet 1.0% 20ml inj vial (Boehringer Ingelheim Vetmedica USA).

Composition: Each ml contains 10mg Romifidine.

• Romifidine 1.0% 20ml inj vial( NexGen USA).

Composition: Each ml contains 10mg Romifidine.

Sevoflurane( Halogenated Ether)

•  Sevoflurane is a sweet-smelling, nonflammable, and volatile inhalational anaesthetic for induction and maintenance of general anesthesia.
•  Approved for use in dogs.
•  Fast onset and even faster than desflurane.

MOA:

• Sevoflurane decreases gap junction channel opening time and increases gap junction channel closing time.
• This leads to  reduction in junctional conductance. Sevoflurane also activates calcium dependent ATPase in the sarcoplasmic reticulum by increasing the fluidity of the lipid membrane.

Effects:

• Muscle relaxation.
• Reduction in pain sensitivity by altering tissue excitability.

Side effects:

• Cough , Salivation , Nausea , Shivering , Vomiting, and dizziness.

Species:

• Dog.

Dose:

• The delivered concentration of sevoflurane should be known. vaporizers should be used to alter depth of anesthesia.

Indications:

• General Surgery.

Contraindications:

• Sensitivity to sevoflurane or other halogenated drugs.

Brands:

Human brands as:

• Sevoflurane 250ml bottle ( Biogene Life Science India).
• Sevorane 250ml bottle(Abbott India).
  
  

Zolazepam (Flupyrazapon).

•  Structurally related to the benzodiazepine drugs.
•   Usually combined with NMDA antagonist Tiletamine or the α2 adrenergic receptor agonist Xylazine.
•  Four times  potent than  diazepam.
• Onset is very fast.

MOA:

•  Zolazepam potentiates inhibitory effect of neurotransmitter GABA at GABAA receptors. The chloride channels  open that result in  hyperpolarization and a reduction in membrane excitability. 
•  Zolazepam combines  with a regulatory site on the GABAA receptor, thereby facilitating the binding of GABA and enhancing its effect.

Effects:

• Sedation.
• Anticonvulsant.
• Muscle relaxation.

Side effects:

•  Copious salivation.
•  Exaggerated swallowing.
•   Vomiting and retching.

Control:

•  Atropine 0.02-0.04 mg/kg as concurrent medication.

Antidote:

•  Flumazenil.

Drug combination:

•  Zolazepam+ Tiletamine 

Species:

•  Dog and Cat.

Dose:

•  2–4 mg/kg IV for induction of anesthesia.
•  2.5–5 mg/kg IM for sedation.

Indication:

•  Induction of anesthesia.
•  Sedation.
•  Minor surgery.
•  Restraint.

Contraindication:

•  Pancreatic disease.
•  Cardiac disorders.  
• Respiratory disorders
•  Renal impairment.
•  Pregnancy.

Brands:

•  Zoletil 50 freez dried inj vial with 5 ml diluent ( Verbac India)

Composition: Each reconstituted ml contains 25g Tiletamine and 25mg Zolazepam.

•  Zoletil 100 freez dried inj vial  with 5 ml diluent( Verbac India)

Composition: Each reconstituted ml contains 50g Tiletamine and 50mg Zolazepam.

Guaifenesin ( Expectorant and SK muscle relaxant).

• Approved for Horse.

MOA:

• Guaifenesin binds GABA activated specific inhibitory neurotransmitter receptor sites in the brain and spinal cord.
• Selectively blocks polysynaptic reflexes in the spinal cord, reticular formation, and subcortical areas of the brain.
• Depress impulse transmission in the internuncial neurons of the spinal cord without impairing breathing.
•  Irritates gastric mucosa followed by  reflex stimulation of the respiratory tract. This is followed by increase in respiratory tract fluid secretions, which helps to loosen phlegm. Viscosity of secretions in reduced and mucociliary clearance is increased so removing accumulated secretions from the upper and lower airway.

Effects:

• Skeletal muscle relaxation.
• Mucolytic effect.

 Species: 

• Horse and  Dog.

Dose:

• As GKX combination:
  1000-2000 mg ketamine + 500 mg xylazine + 5% guaifenesin mixed and added to 1 liter to infuse at 2 mL/kg/hr IV till  anaesthesia. 
• As GKR combination:
  Step 1: Stage of induction
• Premedication with romifidine 100 μg/kg IV.
  Induction with ketamine 2.2 mg/kg IV.
  Followed by Guaifenesin 50 mg/kg IV.
  Step 2 : Maintenance stage
  A) For the first 30 minutes after the induction, constant IV infusion @ romifidine 82.5 μg/kg/hr+ ketamine 6.6 mg/kg/hr+ guaifenesin 100 mg/kg/hr  .
  B) For next 45 minutes  , IV infusion as @ romifidine 82.5 μg/kg/hr+ ketamine 6.6 mg/kg/hr+ guaifenesin 50mg/kg/hr  .
  TIVA with the mixture of GKR provided better cardiorespiratory function during anaesthesia than halothane.
• As GKD combination:
  A)Step 1 : Stage of induction.
  Sedation with detomidine 0.02 mg/kg, IV
  Induction with ketamine 2 mg/kg, IV.
  B)Step2: Maintenance stage  
  Guaifenesin 100 mg/ml/+ Ketamine 4 mg/ml +Detomidine 0.04 mg/ml .
• As expectorant:
  2mg/kg PO TID in dog.

Indications:

•  As part in total Intravenous Anaesthesia in horse.
•  As Sedative before Induction of anaesthesia by Ketamine in horse.
•  As expectorant in dog.

Contraindication: 

•  Horse recieving physostigmine.
•  Close angle glaucoma in dog.
• Hypotension.
• Prostrate enlargement.

Brands:

• Guaifenesin 100ml inj vial( Doclanes pharmacy USA).

Composition: Each ml  contains 100mg Guaifenesin.

• Guaifenesin 500ml inj bottle( Ilium Australia).

Composition: Each ml  contains 100mg Guaifenesin.

• Guaifenesin 500ml inj bottle( Next Gen USA).

Composition: Each ml contains 50mg Guaifenesin.

 Human brands in India.

• Barkiet tablet ( Sanzyme Private
  Limited ).

Composition: Each tab contains 200mg Guaifenesin.