Pharmacology Sedatives And Tranquilizers Flashcards
Study
Tranquilizers
Tranquilizers are drugs that primarily reduce anxiety and produce a calming effect without necessarily causing sedation or sleepiness. They are often used to alleviate anxiety-related behaviors and promote relaxation. Tranquilizers typically work by affecting neurotransmitters in the brain, such as serotonin or gamma-aminobutyric acid (GABA), which are involved in regulating mood and anxiety. Examples of tranquilizers include benzodiazepines like diazepam (Valium) and alprazolam (Xanax), as well as other drugs like acepromazine.
Sedatives
Sedatives, on the other hand, are drugs that induce a state of calmness, relaxation, and drowsiness, often leading to sleep. While sedatives can also reduce anxiety, their primary effect is to induce sedation or mild to moderate central nervous system depression. Sedatives are commonly used to prepare animals for medical procedures, such as surgeries or diagnostic tests, where it’s beneficial for the animal to be relaxed and potentially sleepy. Examples of sedatives include drugs like dexmedetomidine, midazolam, or propofol.
Analgesia
Analgesia is the medical term used to describe the absence of pain or the relief of pain. It involves the reduction or elimination of pain sensations without necessarily causing a loss of consciousness. Analgesia can be achieved through various methods, including medications (analgesics), physical techniques, or a combination of both.
In veterinary medicine, analgesia is a critical aspect of patient care, especially during surgical procedures, after traumatic injuries, or for managing chronic pain conditions. It aims to improve the animal’s comfort, promote faster recovery, and enhance overall well-being.
Phenothiazine tranquilizer
Phenothiazine tranquilizers are a class of drugs that belong to the larger group of tranquilizers or sedatives used in veterinary medicine. Phenothiazine tranquilizers, as the name suggests, are based on the phenothiazine chemical structure.
The most common phenothiazine tranquilizer used in veterinary medicine is acepromazine. Acepromazine is widely used as a sedative and tranquilizer in animals due to its effectiveness and relatively low cost. It is commonly used to reduce anxiety, calm aggressive behavior, and facilitate handling during various veterinary procedures.
Acepromazine works primarily by blocking dopamine receptors in the brain, which results in a calming effect. It does not have significant analgesic (pain-relieving) properties but can enhance the effects of other analgesic medications when used in combination.
what does PO stand for
“PO” is an abbreviation commonly used in veterinary medicine and healthcare in general. It stands for “per os,” which is a Latin term meaning “by mouth” or “orally.”
a1 receptor blockers
A1 receptor blockers, also known as alpha-1 adrenergic receptor blockers or alpha-1 blockers, are a class of medications that work by blocking the effects of adrenaline (epinephrine) on alpha-1 adrenergic receptors. These receptors are found in various tissues and organs throughout the body, including blood vessels, the heart, and the smooth muscles of the urinary tract.
By blocking alpha-1 adrenergic receptors, these medications cause relaxation of smooth muscle in blood vessels, leading to vasodilation (widening of blood vessels). This results in decreased resistance to blood flow and reduced blood pressure. Additionally, alpha-1 blockers may also relax smooth muscle in the prostate and bladder, leading to improved urinary flow and reduced symptoms of benign prostatic hyperplasia (BPH).
Benzodiazepine Tranquilizers
Benzodiazepines are a class of medications commonly used as tranquilizers or sedatives in both human and veterinary medicine. These drugs work by enhancing the effects of gamma-aminobutyric acid (GABA), a neurotransmitter in the brain that has inhibitory effects, leading to relaxation, sedation, and anxiolysis (anxiety relief).
In veterinary medicine, benzodiazepine tranquilizers are often used to achieve various therapeutic goals, including:
Anxiolysis: Benzodiazepines can help reduce anxiety and fear in animals, making them useful for calming anxious pets during veterinary visits, grooming sessions, or travel. Sedation: These medications induce sedation and relaxation, which can be beneficial for facilitating handling, restraint, or minor procedures in animals that may be too anxious or uncooperative otherwise. Muscle Relaxation: Benzodiazepines have muscle relaxant properties, which can be helpful in certain medical situations, such as managing muscle spasms or facilitating intubation during anesthesia induction. Anticonvulsant Effects: Some benzodiazepines have anticonvulsant properties and can be used as part of a treatment regimen for seizures in animals. Adjunct to Anesthesia: Benzodiazepines are sometimes used as adjuncts to general anesthesia to enhance sedation, reduce the required dosage of other anesthetic agents, and provide muscle relaxation.
Commonly used benzodiazepines in veterinary medicine include:
Diazepam: Often used for its anxiolytic, sedative, and muscle relaxant properties. It's commonly administered orally, intravenously, or rectally in emergencies. Midazolam: This benzodiazepine is frequently used for its sedative and anxiolytic effects, especially in small animals and birds. It can be administered intravenously, intramuscularly, or orally. Lorazepam: While less commonly used than diazepam or midazolam, lorazepam can also be used as a tranquilizer in veterinary medicine, particularly for its anxiolytic effects.
It’s essential to use benzodiazepines judiciously and under the guidance of a veterinarian, as they can cause side effects such as sedation, ataxia (loss of coordination), respiratory depression, and paradoxical excitement or aggression in some animals. Additionally, abrupt discontinuation of benzodiazepines after prolonged use can lead to withdrawal symptoms. Therefore, dosages should be carefully calculated based on the individual animal’s needs, and the duration of treatment should be limited to avoid dependence or tolerance development.
GABA
Gamma-aminobutyric acid, commonly referred to as GABA, is a neurotransmitter in the central nervous system that plays a crucial role in regulating neuronal excitability. It is the chief inhibitory neurotransmitter in the mammalian brain, meaning its primary function is to inhibit or reduce the activity of neurons.
GABA acts by binding to specific receptors on the surface of neurons, known as GABA receptors. When GABA binds to these receptors, it causes chloride ions to enter the neuron, resulting in hyperpolarization of the cell membrane and making it less likely for the neuron to generate an action potential (the electrical signal that transmits information along the neuron).
types of Benzodiazepines
Benzodiazepines are a class of medications with various properties, including anxiolytic (anxiety-reducing), sedative, hypnotic (sleep-inducing), muscle relaxant, anticonvulsant (anti-seizure), and amnesic (memory-impairing) effects. There are many types of benzodiazepines, each with its own unique pharmacological profile. Here are some common benzodiazepines used in clinical practice:
Diazepam (Valium): Diazepam is one of the most widely used benzodiazepines. It has anxiolytic, sedative, muscle relaxant, anticonvulsant, and amnesic properties. Diazepam is commonly used for the management of anxiety disorders, muscle spasms, seizures, and as a pre-anesthetic medication. Alprazolam (Xanax): Alprazolam is primarily used for the treatment of anxiety disorders, panic disorder, and panic attacks. It has a rapid onset of action and is shorter-acting compared to some other benzodiazepines, making it suitable for the treatment of acute anxiety symptoms. Lorazepam (Ativan): Lorazepam is commonly used for the short-term treatment of anxiety, agitation, and insomnia. It has sedative, anxiolytic, and anticonvulsant properties. Lorazepam is often used in critical care settings due to its rapid onset of action and relatively short duration of effect. Clonazepam (Klonopin): Clonazepam is primarily used for the treatment of seizure disorders, including epilepsy and certain types of seizures associated with Lennox-Gastaut syndrome. It also has anxiolytic properties and is sometimes used for the management of panic disorder. Midazolam (Versed): Midazolam is a short-acting benzodiazepine commonly used for sedation and anesthesia induction in medical procedures. It has sedative, hypnotic, and amnesic properties, and it is often administered intravenously. Temazepam (Restoril): Temazepam is primarily used for the short-term treatment of insomnia. It has hypnotic properties and is useful for initiating and maintaining sleep. Oxazepam (Serax): Oxazepam is a shorter-acting benzodiazepine commonly used for the treatment of anxiety and alcohol withdrawal. It has anxiolytic and sedative properties. Chlordiazepoxide (Librium): Chlordiazepoxide is primarily used for the treatment of anxiety and alcohol withdrawal. It has anxiolytic, sedative, and muscle relaxant properties.
a2 Agonists-sedative/analgesics
Alpha-2 adrenergic agonists are a class of medications that act on alpha-2 adrenergic receptors in the central nervous system. These receptors are located both presynaptically and postsynaptically in the brain and spinal cord. When activated, alpha-2 adrenergic receptors inhibit the release of norepinephrine, a neurotransmitter involved in the transmission of pain signals and the regulation of arousal and stress responses.
In veterinary medicine, alpha-2 agonists are commonly used as sedatives and analgesics due to their ability to produce profound sedation, muscle relaxation, and analgesia (pain relief). They are particularly useful for procedures that do not require deep anesthesia or for managing pain and anxiety in veterinary patients. Some commonly used alpha-2 agonists in veterinary medicine include:
Xylazine: Xylazine is one of the most widely used alpha-2 agonists in veterinary medicine. It is used primarily as a sedative and analgesic in large animals such as horses, cattle, and deer. Xylazine produces profound sedation, muscle relaxation, and analgesia, but it can also cause significant cardiovascular and respiratory depression. Dexmedetomidine: Dexmedetomidine is a more selective alpha-2 agonist compared to xylazine. It is used in both large and small animals for sedation, analgesia, and as a pre-anesthetic agent. Dexmedetomidine produces a more predictable and reversible sedative effect compared to xylazine and has fewer adverse effects on cardiovascular function. Detomidine: Detomidine is another alpha-2 agonist commonly used in large animals, particularly horses. It is similar to xylazine in its sedative and analgesic effects but has a longer duration of action and is less likely to cause profound cardiovascular depression. Medetomidine: Medetomidine is the active enantiomer of dexmedetomidine and is used primarily in small animal anesthesia. It produces sedation, analgesia, and muscle relaxation and is often used in combination with other anesthetic agents such as opioids and dissociative drugs.
Alpha-2 agonists are typically administered parenterally (e.g., intravenously or intramuscularly) and are often used in combination with other medications to achieve the desired level of sedation and analgesia while minimizing adverse effects. These drugs are reversible with specific reversal agents, such as atipamezole, which competitively blocks the effects of alpha-2 agonists, allowing for a rapid return to normal function.
a2 Agonists
Alpha-2 adrenergic agonists, often referred to simply as alpha-2 agonists, are a class of medications that selectively activate alpha-2 adrenergic receptors in the body. These receptors are found throughout the central and peripheral nervous systems and play a role in regulating various physiological processes.
Alpha-2 agonists produce their effects by mimicking the action of norepinephrine, a neurotransmitter that binds to alpha-2 receptors. When activated, alpha-2 receptors modulate the release of neurotransmitters and hormones, leading to a range of effects depending on their location in the body.
Some common effects of alpha-2 agonists include:
Sedation: Activation of alpha-2 receptors in the central nervous system can lead to sedation and relaxation. This property makes alpha-2 agonists useful for producing calmness and reducing anxiety. Analgesia: Alpha-2 agonists have analgesic (pain-relieving) properties and can be used to manage pain in both acute and chronic conditions. Muscle Relaxation: Alpha-2 agonists can induce muscle relaxation by acting on alpha-2 receptors in the spinal cord, leading to reduced muscle tone and spasticity. Vasoconstriction: Activation of alpha-2 receptors in blood vessels can lead to vasoconstriction (narrowing of blood vessels), which may result in increased blood pressure. This effect can be useful in certain medical contexts, such as controlling bleeding or managing hypotension. Reduction of Norepinephrine Release: Alpha-2 agonists inhibit the release of norepinephrine from presynaptic nerve terminals, leading to decreased sympathetic nervous system activity.
Common examples of alpha-2 agonists used in veterinary medicine include:
Xylazine Dexmedetomidine Medetomidine Detomidine
These medications are commonly used for sedation, analgesia, and anesthesia in veterinary patients. They are often administered parenterally (via injection) and can have significant effects on cardiovascular and respiratory function, requiring careful monitoring when used in clinical practice.
A class of drugs that selectively activate alpha-2 adrenergic receptors in the body. Alpha-2 agonists produce sedative, analgesic, and muscle relaxant effects and are commonly used as tranquilizers and sedatives in veterinary medicine.
Bradycardia
Bradycardia is a medical term that refers to a slower than normal heart rate. In humans, bradycardia is typically defined as a resting heart rate of fewer than 60 beats per minute (bpm). However, in veterinary medicine, the definition of bradycardia can vary depending on the species, breed, and size of the animal.
Bradycardia can be caused by various factors, including:
Increased Vagal Tone: The vagus nerve, which innervates the heart, can be overstimulated, leading to a decrease in heart rate. This can occur due to factors such as increased parasympathetic nervous system activity or stimulation of the vagus nerve during vomiting, gagging, or other events. Certain Medications: Some medications, such as certain types of antiarrhythmic drugs or beta-blockers, can slow down the heart rate as a side effect. Hypothermia: Low body temperature can slow down metabolic processes, including heart rate. Electrolyte Imbalances: Abnormal levels of electrolytes such as potassium or calcium can disrupt the electrical signals that control heart rate. Heart Disease: Bradycardia can be a symptom of certain cardiac conditions, such as sinus node dysfunction or heart block, where the electrical impulses that regulate heart rate are disrupted. Athletic Conditioning: In some cases, particularly in athletic animals, a slow resting heart rate may be a normal physiological adaptation to regular exercise and conditioning.
In veterinary medicine, bradycardia may or may not be associated with clinical signs or symptoms, depending on the underlying cause and the severity of the condition. Treatment for bradycardia depends on the cause. In some cases, no treatment may be necessary if the bradycardia is mild and not causing any adverse effects. However, if bradycardia is severe or symptomatic, interventions such as medications, correction of electrolyte imbalances, or addressing the underlying medical condition may be necessary.
parenterally
“Parenterally” refers to the administration of medications or substances by a route other than through the digestive tract (i.e., not via the mouth or gastrointestinal system). Instead, parenteral administration involves delivering drugs directly into the body via injection or infusion through various routes, such as:
Intravenous (IV): Injection of a medication directly into a vein, allowing for rapid absorption and immediate onset of action. This route is often used for medications that require quick and precise dosing or for fluids and nutrients that need to be delivered directly into the bloodstream. Intramuscular (IM): Injection of a medication into a muscle, where it is absorbed into the bloodstream more slowly than with IV administration. IM injections are commonly used for medications that require sustained release or for drugs that are irritating to veins. Subcutaneous (SC or SQ): Injection of a medication into the tissue layer beneath the skin, where it is absorbed gradually into the bloodstream. Subcutaneous injections are often used for medications that require slow, sustained absorption or for drugs that are too irritating for intramuscular administration. Intradermal (ID): Injection of a small amount of medication into the superficial layers of the skin, usually for diagnostic tests or certain types of immunizations. Intrathecal or epidural: Injection of medication into the space around the spinal cord (intrathecal) or into the epidural space (epidural), often used for pain management or anesthesia during surgery or childbirth.
Parenteral administration allows for rapid and efficient delivery of medications or fluids, bypassing the digestive system and avoiding potential issues with absorption or metabolism that can occur with oral administration. It is commonly used in medical settings for a wide range of purposes, including treatment of acute conditions, administration of anesthesia, and delivery of vaccines or other biological agents.
Anxiolytic
A drug that reduces anxiety and fear without necessarily causing sedation. Anxiolytics are used to alleviate anxiety-related behaviors in animals.
Route of Administration
he method by which a drug is administered to an animal, such as orally (PO), intravenously (IV), intramuscularly (IM), subcutaneously (SQ), or intranasally (IN).
