Veterinary Materia Medica and Pharmacology

Materia Medica

• Study of physical and chemical properties of substances used in medicine
• Originally from plant extracts, bacteria, and animal tissue
• Now largely synthetic
• Evolved into pharmacology

Definition of a Drug

• A chemical compound used on or administered to humans or animals
• Aids in diagnosis, treatment, prevention of disease, pain relief, or control of physiological conditions

Drugs Can Be Poisons!

• A drug can become toxic if administered incorrectly (wrong route, concentration, dose)
• A drug can become toxic if given to the wrong patient or species
• A drug can become toxic if given to food animals without proper withdrawal time

Poison Definition

• A substance that, even in small amounts, may cause structural or functional disturbances when ingested, inhaled, absorbed, injected, or developed within the body

Drug Classifications: Trade vs. Generic Drugs

• Trade (brand-name) drugs have patent protection
• Once the patent expires, other companies can produce generic equivalents (e.g., "Novo-", "Apo-")

Over-the-Counter (OTC) Drugs

• Drugs available without a prescription

Prescription Drugs

• Must be prescribed by a licensed veterinarian
• Provided by a pharmacist or veterinarian
• Requires a Veterinarian-Client-Patient Relationship (VCPR)

Drug Package Insert Includes

• Indications
• Precautions & contraindications
• Overdose risks
• Dosage & administration
• Storage requirements
• Warnings and technical information

Compounded Drugs

• Mixing or altering drugs to create a specific formulation

Reasons for Compounding

• Adjust concentration/strength
• Improve flavor
• Offer alternative administration routes
• Increase availability for different species

Concerns with Compounded Drugs

• Small changes may affect drug efficacy and safety
• Veterinarian may be liable
• Some compounds have short shelf lives

"Extra Label" Drug Use

• All drugs have specific labeled uses
• Using a drug beyond its labeled purpose is extra-label use
• Only DVMs can prescribe extra-label use based on professional judgment
• Regulated by Animal Medicinal Drug Use Clarification Act (1994, USA)
• In Ontario, requires informed consent (CVO regulation, 2018)

Controlled Substances

• A drug with potential for physical addiction, psychological addiction, or abuse

Veterinarian Responsibilities with Controlled Substances

• Ordering, storing, using, and disposing of controlled drugs
• Keeping detailed records for at least 2 years
• Performing monthly audits
• Secure storage is required

Regulations Regarding Controlled Substances

• Controlled Drugs and Substances Act
• Narcotic Control Regulations
• Overseen by College of Veterinarians of Ontario (CVO)

Controlled Drug Log Must Include

• Drug name
• Amount received/used
• Patient details
• Date/time of use
• Administering veterinarian's initials

Prescribing & Handling Medications: Written Prescriptions (Rx)

• A legal document written by a veterinarian
• The author is responsible for accuracy

Labeling Requirements for Prescriptions

• Prescription label must include drug name & concentration
• Dosage instructions, and route of administration
• Expiration date
• Warnings or precautions
• Prescribing veterinarian's information

Safe Drug Handling

• Wash hands before and after handling medications
• Follow manufacturer recommendations for safety
• Be aware of skin/mucous membrane contact risks (e.g., hormones, opioids)
• Follow storage requirements (e.g., refrigeration, light-sensitive drugs)
• Use sharps containers and pharmaceutical waste disposal

Client Education

• Veterinary technicians often educate clients patients on drug name & dosing (when, how much, how often)
• They are also responsible for educating clients about what the drug treats
• When it should take effect and possible side effects
• They are also responsible for educating clients on signs of a drug reaction
• When to seek medical help, how to obtain refills, and how to store medications properly

Reading Syringes & Dosage Measurements: Standard Syringes

• Measured in mL (milliliters) or cc (cubic centimeters)
• Common syringe sizes include 1/2 mL & 1 mL syringes → 0.01 mL increments
• 3 mL syringes → 0.1 mL increments
• 5, 6, 10, and 12 mL syringes → 0.2 mL increments
• Read to the top of the rubber plunger ring, not the tip or bottom

Insulin Syringes

• Measured in International Units (IU)
• Types include U-40 = 40 IU/mL and U-100 = 100 IU/mL
• Syringes are only available in 3/10, 1/2, or 1 mL sizes

Inventory Control

• Proper storage of medications is critical
• Regularly monitor expiration dates
• Keep an accurate log of inventory

Therapeutic Range Definition

• The concentration of a drug in the body that produces the desired effect with minimal or no toxicity

Factors to maintain the therapeutic range

• Right patient – Verify before administration
• Right time – Ensures steady drug levels
• Right drug – Check 4 times (storage, dispensing, returning, before giving)
• Right strength & dosage – Correct concentration and amount
• Right route & technique – Ensures proper absorption and effect
• Right documentation – Legal and safety requirement; owner must consent

Consequences of Mistakes

• Patient harm
• Professional license at risk

Factors Affecting Therapeutic Range

• Drug factors: Absorption, metabolism, excretion
• Animal physiology: Age, weight, health status
• Administration factors: Timing, dose, route

Dose vs. Dosage

• Dosage = Drug amount per unit of body weight (e.g., 2 mg/kg)
• Dose = Total amount given to the patient (e.g., 80 mg for a 40 kg patient)

Dosage Calculation Example

• If the dosage is 2 mg/kg and the patient weighs 40 kg: Dose=2 mg/kg×40 kg=80 mg

Types of Doses

• Loading dose – Higher initial dose to quickly reach therapeutic range
• Maintenance dose – Keeps drug within the therapeutic range
• Total daily dose – Cumulative amount given over 24 hours

Dose Interval

• The time between drug administrations
• Example: "25 mg PO q24h x 7 days" → 25 mg orally, once daily, for 7 days
• Ensured consistent drug levels and prevents toxicity or subtherapeutic effects

Pharmacokinetics (PK) – What the Body Does to the Drug

• Absorption – Drug enters bloodstream
• Distribution – Drug moves to tissues
• Metabolism – Drug is chemically altered
• Excretion – Drug is eliminated

Pharmacodynamics (PD) – What the Drug Does to the Body

• Mechanism of action – How the drug works
• Drug effects: Depression – Slows down function, Stimulation – Increases function, Destruction – Kills cells or microbes, Irritation – Causes local inflammation, Replacement – Supplements deficiencies

Drug Safety & Toxicity: Therapeutic Index (TI)

• TI=LD50/ED50
• LD50 = Lethal dose in 50% of test subjects
• ED50 = Effective dose in 50% of test subjects
• Example: Drug A: TI = 50 (100 mg/kg ÷ 2 mg/kg), Drug B: TI = 5 (10 mg/kg ÷ 2 mg/kg)
• Drug A (higher TI = safer drug)

Routes of Administration

Determined by:

• Drug properties (solubility, stability)
• Patient factors (age, health, species)
• Desired onset time (e.g., surgery requires fast-acting drugs)

Parenteral (Injectable) Routes

• Intravenous (IV) – Fastest effect (100% bioavailability), Bolus - Large dose quickly, Infusion – Continuous administration, Examples: Electrolytes, anesthetics
• Intramuscular (IM) – Rapid absorption (~75% bioavailable), Examples: Vaccines, antibiotics, Risk: Sciatic nerve damage
• Subcutaneous (SC/SQ) – Slower absorption, Used for: Fluids, insulin

Local Routes

• Inhalation – Rapid absorption via lungs, Volatized – Gas form (e.g., anesthesia), Nebulized – Mist/spray (e.g., bronchodilators)
• Topical – Applied to skin or mucous membranes, Factors affecting absorption: Fur, feathers, debris

Oral (PO) Route

• Slower onset than injections
• Affected by: Gastric fluids, food interactions
• First-pass effect: Liver metabolism before systemic circulation

Drug Absorption Factors

• Patient factors – Health, species, GI function
• Route of administration – IV fastest, oral slowest
• Drug properties – Lipophilic vs. hydrophilic
• pH & Ionization: Acidic drugs absorb better in acidic environments, basic drugs absorb better in basic environments
• Example: Stomach pH: 2-3, Duodenum pH: 6-7, Acidic drugs = better absorbed in stomach, Basic drugs = better absorbed in small intestine

Drug Distribution

• Goal: Drug reaches target tissues

Factors Affecting Drug Distribution

• Membrane permeability – Some drugs cross barriers (e.g., blood-brain barrier)
• Protein binding – Some drugs bind to albumin in blood
• Tissue perfusion – Well-perfused organs get drugs faster

Volume of Distribution (Vd)

• High Vd = Drug distributes widely in body
• Low Vd = Drug stays mostly in blood

Effects of Disease on Drug Distribution

• Dehydration = Higher drug concentration in blood
• Edema/Ascites = Diluted drug concentration

Drug Metabolism

• Primary site: Liver
• Secondary sites: Kidneys, intestines, lungs, brain Metabolism Pathways:
• Oxidation – Loss of electrons
• Reduction – Gain of electrons
• Hydrolysis – Water added, splitting the molecule
• Conjugation – Adds glucuronic acid for water solubility

Factors Affecting Metabolism

• Species differences – Cats lack some enzymes
• Age - Young animals metabolize drugs slower
• Liver function – Liver disease slows metabolism

Drug Excretion

• Primary routes: Kidneys (urine), liver (bile/feces), lungs (breath), milk (important for food animals!)
• First-Pass Effect (Oral Drugs): Drug goes from GI → liver before entering bloodstream, some drugs are metabolized before taking effect

Drug Interactions

• Drug-Food Interactions – Food can enhance or block absorption
• Drug-Drug Interactions: Antagonistic – One drug blocks the other, Additive – Two drugs sum their effects, Synergistic – Two drugs enhance each other, Physical/Chemical Reactions – Some drugs precipitate when mixed

Receptor-Mediated Drug Action

• Agonist – Binds to receptor & causes action
• Antagonist – Blocks receptor action, Competitive – Competes for same receptor, Noncompetitive – Alters receptor shape to prevent activation

Common Side Effects

• GI issues – Vomiting, diarrhea
• Neurological – Sedation, hyperactivity
• Dermatological – Photosensitivity, rashes

Why Report Side Effects

• Helps track drug safety
• Prevents future adverse reactions

Nervous System Overview

Neurons (Basic Unit of the Nervous System

• Function: Carry and transmit messages through electrical impulses
• Types: Sensory Neurons – Carry impulses to the CNS, Associative Neurons – Carry impulses between neurons, Motor Neurons – Carry impulses away from the CNS

Structure of a Neuron

• Dendrites – Receive impulses and direct them toward the cell body
• Cell Body – Contains the nucleus, maintaining neuron function
• Axon - Conducts impulses away from the cell body
• Myelin Sheath – Speeds up impulse conduction
• Terminal End Fibers – Transmit messages across synapses

Synapse

• The space between two neurons or between a neuron and a muscle/gland
• Neurotransmitters (NTs): Chemicals that transmit signals across synapses
• Drugs can act as: Agonists (mimic NTs and stimulate action), antagonists (block NTs and prevent action)

Divisions of the Nervous System

Central Nervous System (CNS)

• Includes: Brain and spinal cord
• Function: Processes sensory information and sends out motor responses
• Protection: Meninges: Three layers (DAP – dura mater, arachnoid mater, pia mater), cerebrospinal Fluid (CSF): Cushions and nourishes CNS

Peripheral Nervous System (PNS)

• Cranial nerves – Originate from the brain
• Spinal nerves – Originate from the spinal cord, Dorsal root: Sensory impulses to the spinal cord, Ventral root: Motor impulses from the spinal cord

Autonomic Nervous System (ANS)

• Controls involuntary functions (smooth muscle, cardiac muscle, glands)
• Divisions: Sympathetic Nervous System (SNS) and Parasympathetic Nervous System (PSNS)

Sympathetic Nervous System (SNS)

• “Fight, Flight, Freeze, or Fret" (energy expending)
• Key Neurotransmitters: Preganglionic NT: Acetylcholine, postganglionic NTs: Norepinephrine & Epinephrine
• Receptors: Alpha-1: Vasoconstriction (↑ BP), alpha-2: Sedation, muscle relaxation, Beta-1: ↑ Heart rate, contractility, Beta-2: Bronchodilation, Dopaminergic: Vasodilation (renal, mesenteric, cerebral arteries)

Parasympathetic Nervous System (PSNS)

• “Rest and Digest" (energy conserving)
• Key Neurotransmitter: Acetylcholine
• Receptors: Muscarinic receptors – Located in smooth muscle, heart, glands, Nicotinic receptors – Found in neuromuscular junctions

Autonomic Nervous System Drugs: Sympathomimetics (Adrenergic Agonists)

• Function: Mimic epinephrine/norepinephrine, activating SNS
• Uses: Stimulate the heart during cardiac arrest, treat hypotension & bronchoconstriction, control urinary incontinence
• Examples: Epinephrine: ↑ Heart rate, bronchodilation, vasodilation, Norepinephrine: Vasoconstrictor; increases BP, Dopamine: Improves renal perfusion, Albuterol, Terbutaline: Bronchodilators

Sympatholytics (Adrenergic Antagonists)

• Function: Block SNS effects, causing vasodilation or heart rate reduction
• Uses: Treat hypertension, heart conditions, or reverse anesthesia drugs
• Examples: Phenoxybenzamine, Prazosin: Vasodilators, Propranolol, Atenolol: Reduce heart rate (Beta-blockers), Yohimbine, Atipamezole: Reverse alpha-2 agonists like xylazine
• Side Effects: Sympathomimetics: Tachycardia, hypertension, arrhythmias, sympatholytics: Bradycardia, hypotension, heart block

Parasympathomimetics (Cholinergic Agonists)

• Function: Mimic acetylcholine, activating PSNS
• Uses: Treat urinary retention, stimulate Gl motility, reduce intraocular pressure (glaucoma)
• Examples: Pilocarpine: Treats glaucoma, metoclopramide: Increases Gl motility, Bethanechol: Treats urinary retention

Parasympatholytics (Cholinergic Antagonists)

• Function: Block acetylcholine effects, inhibiting PSNS
• Uses: Pre-anesthetic to dry secretions, treat bradycardia, reduce vomiting/diarrhea

CNS Drug Classes

• Anticonvulsants, tranquilizers, sedatives, & anti-anxiety drugs, CNS stimulants, euthanasia agents

Anticonvulsants (AEDs)

• Function: Reduce frequency & severity of seizures
• Long-term therapy: Oral (PO); Emergency therapy: IV or rectal (PR); Monitoring required: Blood work for drug levels & liver function
• Examples: Phenobarbital: Long-acting; affects liver enzymes; Diazepam (Valium®): Emergency seizure control; Levetiracetam (Keppra®): Adjunct for epilepsy; Potassium Bromide (KBr): Avoid in cats (lung toxicity); Pentobarbital: Used for euthanasia in high doses

Tranquilizers, Sedatives, & Anti-Anxiety Drugs: Phenothiazine Derivatives

• Example: Acepromazine
• Effects: Sedation, anti-emetic
• Side Effects: Hypotension, hypothermia, paraphimosis in horses

Benzodiazepine Derivatives

• Examples: Diazepam, Midazolam, Zolazepam
• Effects: Anti-anxiety, muscle relaxation
• Minimal CV depression
• Reversal Agent: Flumazenil

Alpha-2 Agonists

• Examples: Xylazine, Dexmedetomidine
• Effects: Sedation, some analgesia
• Reversals: Yohimbine (for xylazine), Atipamezole (for dexmedetomidine)

Euthanasia Agents

• Function: Induce unconsciousness and painless death; controlled drugs except for T-61®
• Examples: Pentobarbital sodium (Fatal-Plus®), pentobarbital + blue dye (Beuthanasia-D®), T-61®: Non-barbiturate, contains muscle paralyzers

CNS Stimulants

• Function: Stimulate respiration in cases of respiratory depression
• Example: Doxapram: Used for newborns or anesthetic recovery

Drugs for Muscle Functioning: Basic Skeletal Muscle Physiology Types

• Skeletal Muscle (Voluntary)
• Smooth Muscle (Autonomic NS)
• Cardiac Muscle (Autonomic NS)
• Neuromuscular Junction: the point where a motor nerve meets a muscle fiber

Requirements for Muscle Contraction

• Motor nerve sends electrical impulse
• Neurotransmitter (Acetylcholine - Ach) is released
• Ach binds to muscle receptors, triggering a charge movement
• Calcium is released, leading to muscle contraction
• Acetylcholinesterase breaks down Ach, preventing continuous contraction

Drug Categories for Muscle Function: Anti-Inflammatory Drugs

• Used to reduce redness, pain, swelling, heat, and limited movement

Types of Anti-Inflammatory Drugs

• Steroidal (Glucocorticoids): Drugs: Prednisone, Prednisolone, Dexamethasone, effects: Strong anti-inflammatory action but suppresses the immune system
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Function: inhibit prostaglandin synthesis to reduce inflammation

Neuromuscular Blockers (NMBAs)

• Function: Block nerve impulse transmission to skeletal muscles
• Uses: Surgery (e.g., ocular, thoracic, orthopedic), intubation, general anesthesia support Types:
• Competitive Non-Depolarizers: Example: Pancuronium, Action: Blocks Ach receptors → Muscle cannot contract, Reversal: Acetylcholinesterase inhibitors (Neostigmine, Edrophonium)

Spasmolytics (Muscle Relaxants)

• Function: Reduce muscle spasms
• Drugs: Methocarbamol (Robaxin-D®) – Reduces spasms without affecting muscle tone; Guaifenesin (Guailaxin®) – Used in large animal anesthesia; Diazepam (Valium®) – Centrally acting muscle relaxant; Dantrolene (Dantrium®) – Peripherally acting; blocks calcium release in muscles

Anabolic Steroids

• Function: Promote muscle growth, counteract atrophy, stimulate RBC production
• Used as an adjunct to nutritional therapy
• Drugs: Stanozolol (Winstrol-V®) – Used in dogs, cats, and horses (NOT for food animals or pregnant animals); Boldenone (Equipose®) – Used in horses (NOT for food animals or pregnant mares); Nandrolone (Compounded if needed) – Used to treat anemia
• Anabolic steroids are controlled substances

Cardiovascular Drugs: Basic Cardiac Physiology Functions

• Delivers oxygen, nutrients, and hormones
• Removes waste products
• Maintains blood pressure and circulation

Heart Conduction System

• Sinoatrial (SA) Node → Atrioventricular (AV) Node → Conduction pathways
• Controlled by the Autonomic Nervous System (ANS): Parasympathetic (Acetylcholine) → ↓ Heart Rate; Sympathetic (Epinephrine/Norepinephrine) → ↑ Heart Rate

Common Cardiac Conditions

• Congestive Heart Failure (CHF): Causes: cardiomyopathy, hypertension, valvular disease; Fluid accumulation: Pulmonary edema (Lung); Pleural effusion (Around the lungs); ascites (Abdomen)
• Arrhythmias: Caused by SA node dysfunction, abnormal conduction, electrolyte imbalances.
• Cardiomyopathy: Dilated Cardiomyopathy (DCM) – Common in dogs; weak heart muscle; hypertrophic Cardiomyopathy (HCM) – Common in cats; thickened heart muscle

Valve Disease

• Leaky valves cause blood backflow
• Mitral valve disease → Pulmonary edema
• Tricuspid valve disease → Ascites

Cardiac Drug Classifications: Cardiac Stimulants (Catecholamines)

• Function: Increase heart rate and contraction strength

CHF Treatment

• Cardiac Glycosides (Digitalis Drugs): Drugs: Digoxin, Digitoxin. Effects: ↑ Heart contraction strength; ↓ Heart rate; side effects: low therapeutic index (Toxicity risk – monitor blood levels)
• Inodilators: Example: Pimobendan: Uses: CHF, dilated cardiomyopathy (DCM); side effects: anorexia, lethargy, diarrhea

Antiarrhythmic Drugs Function

• Function: Restore normal heart rhythm
• Classes: Class IA (Na+ Channel Blockers) – Procainamide, Quinidine; Class IB (Membrane Stabilizers) – Lidocaine (IV only, not PO); Class II (Beta Blockers) – Propranolol, Atenolol (↓ Heart rate, ↓ Oxygen demand); Class III (K+ Channel Blockers) – Sotolol, Amiodarone (Ventricular arrhythmias); Class IV (Ca++ Channel Blockers) – Diltiazem, Verapamil (Atrial fibrillation, hypertension)

Drugs Acting on Blood Vessels (Vasodilators)

• Function: Reduce heart workload by relaxing blood vessels
• Types: Arteriole Dilators (Hydralazine) – Lowers afterload; ACE Inhibitors (Enalapril, Benazepril) – Blocks vasoconstriction, used in CHF; Venodilators (Nitroglycerin) – Increases vascular capacity, reduces pulmonary edema; Combined Vasodilators (Prazosin) – Treats CHF, hypertension

Hematological Drugs: Anticoagulants

• Function: Prevent clot formation
• Examples: Aspirin: Prevents platelet aggregation; EDTA: Used for blood samples; Heparin: Prevents thrombosis

Hemostatic Drugs

• Function: Promote clot formation
• Examples: Vitamin K – Treats rodenticide poisoning; Protamine Sulfate – Reverses heparin overdose; Silver Nitrate, Stop – Stops external bleeding

Blood-Enhancing Drugs

• Function: Stimulate RBC production
• Examples: Iron supplements – Treat anemia; Erythropoietin – Stimulates bone marrow to produce RBCs

Respiratory System Overview: Functions

• Delivers oxygen (O2) to RBCs
• Removes waste (CO₂) from RBCs
• Gas exchange occurs in the alveoli
• Two parts: upper respiratory tract (URT) and lower respiratory tract (LRT)

General Respiratory Tract Information

• Upper Respiratory Tract (URT): Nares, nasal cavity, pharynx, larynx
• Lower Respiratory Tract (LRT) Trachea, bronchi, bronchioles, alveoli
• URT defenses: Nasal hairs, sneezing, mucus secretion, coughing, gag reflex
• LRT Goblet cells (mucus production), cilia (mucociliary escalator), alveolar surfactant

Types of Coughs

Productive Cough (PC): produces mucus (phlegm)

• Non-Productive Cough (NPC): dry, no mucus

Respiratory Drug Classifications

• Antitussives (Suppress coughs)
• Mucolytics, Expectorants, & Decongestants (Break up or thin mucus)
• Bronchodilators (Open airways)
• Miscellaneous (Antihistamines, respiratory stimulants)

Antitussives (Cough Suppressants)

• Function: Reduce frequency & severity of NPCs without impairing mucociliary defenses
• Used for: canine infectious respiratory disease complex (CIRDC), tracheitis, tracheobronchitis
• Suppress the cough reflex in the brainstem
• Controlled drugs: butorphanol, codeine, hydrocodone, Non-controlled drugs: dextromethorphan, trimeprazine

Mucolytics, Expectorants, & Decongestants: Mucolytics

• Break down mucus, used for 'wet' coughs (PC) where there us thick mucus that is hard to clear.
• Decrease mucus viscosity by breaking chemical bonds
• Drug example; Acetylcysteine (Mucomyst®)
• Also treats acetaminophen toxicity

Expectorants

• Increase liquid secretions in respiratory tract; used for "wet" coughs (PC)
• Thins mucus, making it easier to cough up
• Also keeps nasal passages moist
• Drug: Guaifenesin: limited benefit in cats/dogs, used in horses as a muscle relaxant

Decongestants

• Reduce nasal swelling
• Limited use in veterinary medicine – more common in humans
• Feline upper respiratory tract disease
• Decrease nasal tissue edema
• Alternative: Warm compresses, nebulization, saline drops
• Drug: Phenylephrine, caution: Can cause cardiac stimulation (do not use in hypertensive or tachycardic animals)

Bronchodilators (Open Airways)

• Causes of Bronchoconstriction: parasympathetic dominance; beta Blockers; histamine release
• Types of Bronchodilators: anticholinergics, beta-2 adrenergic Agonists; methylxanthines

Respiratory Drugs: Anticholinergics

• Blocks parasympathetic to help prevent bronchodilation
• Effect: Prevents bronchoconstriction
• Drugs: Aminopentamide, Atropine, Glycopyrrolate

Beta-2 Adrenergic Agonists (Stimulate Bronchodilation)

• Stimulates beta-2 receptors to relax airway muscles
• Additional benefits: ↓ Histamine release, mucolytic action
• Drugs: Terbutaline, Mesoproterenol

Drugs Used for Emergency Use Only

• Epinephrine: used for anaphylaxis, cardiac arrest. Acts on multiple receptors: Beta-2, Beta-1, Alpha-1

Methylxanthines (Inhibit Bronchoconstriction Enzymes)

• Inhibits phosphodiesterase (promotes airway relaxation)
• Side effects: narrow therapeutic index, GI irritation, CNS stimulation

Anti-Histamine Medications

• Helps counter symptoms induced by histamine release, for use with asthma or allergic reactions

Miscellaneous Respiratory Drugs

• Block Histamine-Induced Bronchoconstriction
• Block H1 receptors, prevents airway inflammation
• Drugs: Diphenhydramine, Chlorpheniramine
• Side effects: CNS depression, dry mouth, urinary retention

Diuretics & Oxygen Therapy

• Diuretics – Help remove fluid from the lungs (e.g., pulmonary edema)
• Oxygen Therapy – Improves oxygenation in critical cases

Respiratory Stimulants

• Function: Stimulate beathing in the neonate or during anesthesia recovery
• Drugs: Doxapram: applied under tongue or umbilically; Narcan: reverses opiod-induced respiratory depression; yohimbine: reverses xylazine-induced respiratory depression

How the Body Responds to Cancer Drugs

• By using normal body defences
• Immune system tries to eliminate cancer Via: T Lymphocytes, Antibodies, Interferons & Tumour Necrosis Factor (TNF)
• Eventually the Immune is overwhelmed, and the cancer continues to grow

Antineoplastic (Chemotherapy) Drugs

• Targets Cancer Drugs, and kills any rapidly reproducing cells.
• Challenges: Cancer cells mutate and develop drug resistance, Drugs can harm normal, fast dividing cells And a Narrow margin of safety.

Dosage for Treating and killing malignant cells

• Most drugs are dosed based on body weight (kg), but Antineoplastic Drugs are dosed based on body surface area (BSA (m2)

Considerations when Using anti cancer drugs

• Use specialized Gloves and PPE to administer.

Cancer Cells Growth and Drug Targets

Cancer cells in cycle phases:

• G1 Phase: Enzymes for DNA synthesis are are produced
• S Phase: DNA Synthesis and Replication
• G2 Phase: RNA and portein synthisis
• M Phase: Mitosis ( Cell division)
• Go Phase: Reating phase ( non - dividing cells)

2 Main types of CC Drug classes

1. Cell Cycle Non Specific ( CCNS )DRUGS

• Work is ALL phases of the cell, active AND resting

2. Cell cycle specific ( CCS ) drugs

• Only affected in cell division; Not affective in resting phase

List of Alkylating Agents Chemotherapy

• How they work: attatch a Alkyl group to DA
• Prevents cell replication
• Examples: Cycolphosphamide, Chlormbucil & Cisplantin
• SE: myelosupression Nausea, vomiting & diarhea, hemorrhagic cystis ( bladder irritation)

Anitumor Antibiotics

How : Interfere with DNA AND RNA synthesis, and prevent cancer cells from dividing

Examples ( Adriamiycon)Doxorubicin, Mytocantrone and Actinonyscin D

SE: Cardio toxitym severe tissue damage if injected outside the vin, myelosupression, nausea and vommitting

Antimetabolites

How: dirupt normal cell metabolism, mimic natural cell component causing faulty DNA/ RNA synthesis Examples: methotraxate, 5- Florouracil Side effects include: ,neurological toxicuty ( toxic to cats ), myelosupression and GIT Toxisity's

Common Side Effects of Chemotherapy

• Affected Tissues include
• Bone Marrow
• Gastrointestinal Tract (Gl)
• Reproductive Organs
• Hair Follicles:

Safety Considerations When Handling Chemotherapy

Wear PPE (gloves, masks, gowns) when handling antineoplastic drugs Avoid skin contact & inhalation of drug particles Used Special IV Catheters to prevent exravasation properly dispose of drug waste

Dermatological Drugs

3 layers of the skin Epidermis: Outher layer, contains melanocytes Dermis - Glands, hair follicles Hypodermis - subctaneous Fat layer Common things to consider: Licking can couse systemic abosoprtion, drug removal and worsening if skin issues

Function: treat bacterial skin infections

• Common Ingredients: Bacitracin + Polymyxin + Neomycin, Gentamicin + Betamethosone, Neomycin + Thistrepton, Nitrofurasone

Antifulgal Meds: Function and drug calsses

Treat Fungal and yeast infections Classes are: Imidozoles & Polyenes

• Examples: Myconizole.Ketoconizole

Functions and Drug Classes

Antipuritics

• Example Lydicain: Sooting agent : Collidal oatmeal
• Function Ainti- inflamatuatory, reduces redness and swolling

Anti-seborhetic Drugs

• For dry flaky skin or exessive oil prodection
• Commin Ingredents: Solicylic acid, benzoyl peroxide and sulfide

Oral Skin Meds

• For allergies
• Examples: Oclacitinib and Cytopoint
• Oral or Eye Meds

Used during Eye tests or Procedures: Diagnostic Eye Drugs

• Examples: fluoresent stain and proparcane

Types of ophthalmic glaucoma and related drugs

• Miotics,mydraulics.carbanic Anhydraase inhibitors Beta-Blockers Glaucoma Drugs

Key concempts when studying exam

Important steps and considuarts as of Admin and Pharmacokinetics Beaware of right patient and document everything Absorbtion - Blood streams; Distribution -how drugs enters and leaves Liver is a main player to make sure enzymes are balanced

key points of AutoNervous System(ANS)Drugs

Sympathetic Nervous System “Fight OR Flight" Neurotransmitters: Epinephrine and Norepinephrine. Receptors a 1 and 2 beta 1 and 2 Parasympathetic Nervous System (PSNS) “Rest OR Digest" Neurotransmitter: Acetylcholine (Ach).

Cardiovascular Drugs

If Cardiac output decreases compensation increases, Heart Rate Drugs:Pimobendan, Digoxim ace inhibatiors and diuretics is

Antibiotics Drug Types

• • Types: Naloxone and flumazenil reverses over dose and Dexmedetomidine.