pharma lec Hypnotics, Sedatives, and Tranquilizers

Animals are in deep sleep

Hypnotics

• Animals are awake 

• Used to calm the animal

• Reduces the physical or motor activity 

• Drowsiness and analgesia

Sedative

• Animals are awake 

• Used to calm the animal

• Reduces the psychological, mental, or emotional activity 

• Without drowsiness

Tranquilizers

• Through the oral route or injectable (low dose it will become hypnotic) 

• In a much lower dose, it will become a sedative

Barbiturates

• The first barbiturates to be used in practice/clinical importance

• It cannot be given IV as a hypnotic because it tends to paralyze the vital medullary center

• There will be no stage 1, 2, or 3; Directs to stage 4

Barbital

• The second barbiturate with clinical importance

  • Tumor-producing agent

  • For sedative purposes

• Can be used as an anesthetic

• It is given orally (tablet) for the sedation effect

Phenobarbital

• IV route is preferred except in carnivores (dogs and cats)

• In dogs and cats, it can be given orally, thus having a hypnotic sedative effect

Amobarbital

• It resembles barbital sodium, which is more potent and short-acting

Secobarbital

• It is given orally for sedation purposes

• In swine, it can be given intramuscularly for mild sedation

Pentobarbital

• Poor anesthetic but good hypnotic

• One of the oldest seductive

• Dependable for the large animal

• Not dependent on carnivores due to irritation in the stomach 

• Sedation occurs rapidly if the animal is fasted

  • Large animals do not vomit or experience  irritation in the stomach

• Reduce the dose of acepromazine maleate by ½

Chloral hydrates

• Muscle relaxants 

Benzodiazepine

• Brand Name: Valium

• Most commonly used

• Action:

  • Hypnotic

  • Sedative

  • Tranquillizer

  • Mood stabilizer

• Convulsive seizures

Diazepam

• Hypnotics 

• Mixed with zolazepam

Midazolam

Normally, it may cause an effect on the liver, which causes icterus.

Chlordiazepoxide

• Tranquilizer/sedative without analgesic effect

Phenothiazine Group

• Most commonly used pre-anesthetic drug

• Commonly used in horses, because visual and auditory activity is not affected (retained). 

• But it causes Priampism in Horses, which is penile prolapse and does not retract. 

Acepromazine

• Epinephrine is contraindicated with Chlorpromazine 

• Used as an anti-emetic (vomiting) drug in dogs, but not in cats 

• Used as an anti-arrhythmic (Irregular heartbeat) drug 

• It increases the function/activity of Dichlorvos (OP-compound) and Physostigmine (ACh Inhibitor)

  • Lower the dose when used

Chlorpromazine

• Seldom used in equine practice because before the horse experiences hypnosis, it would experience little excitement

Promazine

• Mostly used in small animal practice as a sedative, to calm the patient (ex., grooming).

• It is used to prevent self-mutilation associated with dermatoses in dogs, to quiet the animal

Ethylisobutrazine

• It can be used in all animals except sheep (not prohibited, but use with caution)

• In sheep, it affects the erythrocytes (RBC)

Triflupromazine

• It is a good anti-emetic and antihistamine 

• Use with caution in Pigs, it increases the body temperature, leading to Hyperthermia

  • But not more than malignant hyperthermia (increased body temperature with seizures

Chlorprothixine

• Has an anti-emetic action

• Epinephrine is contraindicated 

• Use with caution for dairy/lactating animals

• It may cause Galactorrhea (excessive excretion of milk)

  • Galactose - a sugar in milk

Droperidol

• It is also a psychotropic drug 

• Treatment for a psychiatric disorder

• It may cause Galactorrhea (excessive excretion of milk) 

Haloperidol

• Used in swine to prevent aggressiveness and fighting in piglets and sows

  • Swine have a hierarchy

  • Usually, gilts are aggressive 

• Brand name: Stresnil (injected);  (alternative is Redhorse) 

• It is also used to correct malignant hyperthermia in swine

Azaperone

• Used as an anti-emetic and anxiolytic

• It has an opposite effect on temperature

• It causes hypothermia (decreased temperature)

  • Can be corrected by phenylephrine

Leperone

• Neuronal blocking sympatholytic drugs 

Reserpine

• Used for birds and chickens

Methoserpate

• They are any drugs that stop or prevent convulsions for any form or reason. 

• The difference from Neuromuscular blocking drugs

  • Muscle relaxants and skeletal muscle spasmolytics are drugs under ANS, meaning the spasms are localized or involve small portions

  • Muscle relaxants are used to prevent anticipated spasms

  • Skeletal muscle spasmolytics are used to treat spasms that are already occurring but localized (tetanus)

• The tremor or epilepsy is generalized or involves large portions (all of your muscles)

• The source of tremors is under the brain

• These are drugs that act on the brain and spinal cord

• Drugs that are under CNS

Anticonvulsant

Specific for epilepsy

Antiepileptic

There is a continuous seizure for almost 30 minutes with consciousness.

Status Epilepticus

• Also known as Tonic-clonic Epilepticus or Grand mal Epilepticus. 

• There is a continuous seizure for almost 30 minutes without consciousness.

Convulsive Status Epilepticus 

• To treat epilepsy

• They are interchangeable with anticonvulsant drugs, but strictly not

• Not all tremors are caused by epilepsy

• Some tremors are caused by poisoning or distemper

Antiepilepsy Drugs

• Should not be left in a plastic container due to rapid inactivation. 

• Diazepam is the drug of choice for cats in both initial and maintenance treatment (status epilepticus)

• Cats have no enzymes in the liver

• Diazepam has an anxiolytic effect

• Diazepam is the 2nd choice of drug for dogs

Diazepam

• Can be used for emergency purposes, and not for long-term therapy

• Causes diarrhea in dogs and cats

Clonozepam

• An option when Diazepam and/or Clonazepam are not available. 

Clorazepate

• It is the drug of choice for controlling status epilepticus in dogs via the oral route. 

• For the parental route, Phenobarbital is used as treatment for Status Epilepticus in dogs.

• Preferred maintenance for the treatment of dogs

• It is the 2nd choice for cats

Phenobarbital

• No longer recommended for dogs and cats, especially during emergency cases of poisoning

Phenytoin

• For use only in dogs, but not recommended for cats (toxic)

  • The toxic effect is immediate in the liver as compared to phenobarbital 

Primidone

• Generally reserved as the last resort when maintaining drugs for epilepticus 

• Not recommended for emergency poisoning, but can be used for other causes of seizure. 

Pentobarbital

• Treatment for refractory cases of status epilepticus or as a last resort

• Antimicrobial resistance - when bacteria is not killed by an antibiotic

• Refractory - a disease that cannot be treated 

• Used when the previous medicines are no longer effective. 

Valproic Acid/Valproate

• There are some research or books that it is prohibited, but some are recommended to be used during tremors or distemper in dogs

• Used with caution on dogs (toxic)

• Gabapentin with Xylitol is toxic when xylitol is the toxic factor to dogs

• When there is no xylitol added to the mixture, you can use the drugs on dogs

Gabapentin