NSAIDs & GI & Chemo Drugs Flashcards
What 3 main actions do NSAIDs do?
- Anti-inflammatory
- Analgesic
- Anti-pyretic
What does NSAIDs stand for?
Non-steroidal anti-inflammatory drugs.
What is COX?
NSAIDs inhibits COX which stands for cyclo-oxygenase enzymes.
What and When are the two different COX enzyme used?
COX-1
- Found in most of the body tissues.
- Involved in homeostasis
COX-2
- Induced in inflammatory cells when activated.
- Responsible for inducing inflammatory medications.
Describe the NSAIDs mechanisms of action.
The majority of NSAIDs inhibit BOTH COX-1&2.
The anti-inflammatory effect is produced by the COX-2 enzyme.
The side effects are caused by the COX-1.
So many practices use COX-2 selection.
How does NSAID provide analgesia?
- Effective against pain of inflammation or tissue damage.
- Decrease prostaglandin production that sensitises the pain receptors.
- Most effective against pain of muscular, skeletal and vascular origin. Less effective against visceral pain.
- Used in combination with opioids for post-op pain.
What is Prostaglandins?
This is produced by inflammation that alter the firing rate of neurons in hypothalamus which controls the thermoregulation.
How does Anti-pyretic work?
- This increases the body’s thermal set point = fever.
- Maintained by vasodilation and sweating.
- NSAIDs inhibit PG production, reducing pyrexia.
What are the properties of Meloxicam?
- Commonly used in veterinary NSAIDs.
- Licensed in dogs and cats
- Oral suspension, oral tablets, solution for injection - SC.
- Preferably inhibits COX-2.
What are the uses of Meloxicam?
- Acite and chronic muscoskeletal pain.
- Post-op -orthopaedic and soft tissue procedures.
What are the contraindications of Meloxicam?
- Dehydration
- Hypotension
- GI disease
- Pregnancy
- <6 weeks old
What are the adverse reactions of Meloxicam?
- V+ D+ GI Ulcerations and bleeding.
- NOT to be administered with other NSAIDs or corticosteriods.
What are the properties of Carprofen?
- Injection - IV,SC, oral tabs.
- Inj licensed for Dogs and Cats. Tabs only dogs.
- ## Preferential COX-2 inhibition.
What are the uses of Carprofen?
Uses are similar to Meloxicam
What are the adverse reactions of Carprofen?
V+ D+ GI Ulcerations and bleeding.
- NOT to be administered with other NSAIDs or corticosteriods.
How should Carprofen be administered?
With Food.
What are the properties of Firocoxib?
- COX-2 inhibition.
- To have lesser effects on GI tract then Meloxicam/Carprofen.
- Licensed for dogs only.
- Oral tabs.
- Can be given with/out food.
What are the adverse reactions of Firocoxib?
- V+ D+ GI Ulcerations and bleeding.
- NOT to be administered with other NSAIDs or corticosteriods.
What 3 other NSAIDs drugs are used in practice?
Robenacoxib - Onsior
Cimicoxib - Cimalgex
Mavacoxib - Trocoxil
What are the properties of Paracetamol?
Licensed in dogs as Pardale-V (+codeine)
Not considered an NSAIDs as it treats pain mainly by blocking COX-2 in the central nervous system.
Why can Parcetamol NOT be given to cats?
- Cats lack the glucuronyl transferase enzyme to metabolise paracetamol - toxic intermediates NAPQ-1.
Damage RBCs
Liver damage - icterus
How does Paracetamol damage RBCs in cats?
- Causing methaemaglobinaemia - chocolate brown MM - cyanosis.
- Anaemia
- Haemoglobinuria
What are the treatment for paracetamol toxicity in cats?
- IV fluids
- Blood transfusion
- N-acetycysteine
-Increased glutathione reserves in liver and enhances metabolism
May cause anaphylaxis
What does the Medulla, hormones secrete?
- Adrenaline
- Noradrenaline
What do the hormones secrete do to the body?
- These prepare body for “fight” or “flight” situations in combination with the sympathetic nervous system.
What two anatomical landmarks the Adrenal Glands obtain?
Medulla and Cortex
In the cortex, what hormones are produced?
Steroids
What are the three groups of Steroids?
- Glucocorticoids
- Mineralocorticoids
- Adrenal Sex hormones.
Why do the Glucocorticoids secrete?
- In response to stress.
What is the Glucocorticoids responsible for?
- increase in bloog glucose.
- Aid in control of electrolytes (e.g. Ca).
- Anti-inflammatory response/suppress immune response (inhibits prostaglandin A2).
What are Mineralocorticoids responsible for?
- Aldosterone - Retain Na, Excrete K.
Increase blood volume and blood pressure.
How often do sex steroids produce for?
Produced in small amounts.
How is Cortsol release controlled?
- Controlled by negative feedback.
How is Cortisol released?
- Low blood cortisol stimulates ACTH release from anterior pituitary gland.
- Stimulates corticosteroid release from adrenal gland.
- Exogenous steroid increases blood cortisol levels and so inhibits ACTH production.
What hormones do glucocorticoids secrete?
- Hydrocortisone (Cortisol) and Cortison (inactive form).
What synthetic drugs come under the glucocorticoids drugs?
- Prednisolone
- Methylprednisolone
- Betamethasone
- Dexamethasone
- Triamcinolone
What are the effects of Glucocorticoids?
Metabolic - - Converting protein to glycogen.
- Stimulates protein catabolism to AAs
- Glucose uptake inhibited.
What anti-inflammatory effects does Glucocorticoids have?
- Decrease all stages of inflammatory process and later stages in chronic inflammation.
- Immunosuppressive.
What have you seen glucocorticoids used for?
- Suppress inflammation.
- arthritis, colitis etc.
- Allergy
-asthma, atopic dermatitis etc - Immune response
- IMHA, lymphoma etc.
Different effect according to increasing dose levels.
How is Hydrocortisone used?
- Addisons treatment (Oral), shock (IV) Topical ointments.
Why is Prednisolone used?
inflammatory and allergic diagnosis (oral).
What is Betamethasone Diproprionate used for?
Asthma (inhalation).
What is Triamcinolone used for?
Severe asthma, intra-articular injection for arthritis.
When an increase of the adrenal gland, what is secreted?
Increased secretion known as cushings disease
When a decrease of adrenal gland, what is secreted?
Decrease secretions known as Addisons disease
What is Betamethasone and Dexamethasone used for?
- Very potent (25-30x)
- High dose indications.
What are some of the adverse effects associated with glucocorticoid treatment?
Higher doses produce similar effects to that of cushing’s disease -(steroid excess)
How is Hydrochloric acid produced?
In the fundus by parietal cells.
What are the clinical signs associated with this disease and how it is treated?
- Muscle wasting
- Thin skin and poor habit coat
- PU/PD
- Polyhagia
- Panting
- Restlessness
How is Mucus produced?
Produced throughout the stomach y Goblet cells. Prevents AUTO DIGESTION
How is Gastrin produced?
Hormones produced in fundus by G cells >stimulates HCL production
What 4 functions of GIT that drugs focus on?
- Gastric secretion
- V+ (emesis)
- Motility of the intestines
- Bile formation/excretion
What is the process of regulating acid secretion?
- Stomach parietal cells produce HCL
- Secreted via a proton pump (K+/H+)
- Regulated by (stimulated acid secretion)
- Prostaglandins inhibits acid secretions.
What are the indication that drugs inhibit gastric acid secretion?
- Gastric or duodenal ulcer
- Reflux oesophagitis
- Zollinger - Ellison Syndrome (gastrin-producing tumour).
What are the methods of action when drugs inhibit GAS? (gastric acid secretion)
- Histamine H2 receptor antagonist
- Proton pump inhibitors
- Antacids to neutralise secreted acid.
What example of drugs of Histamine receptor antagonist?
Famotidine
Cimetidine
Ranitidine
What example drugs of Proton pump inhibitors?
Omeprazole
Aspirin
What examples drug of antacids?
Gaviscon
Maalox
What are the side effects of Histamine receptors blockers?
Constripation D+ Restlessness Hypotension Arrythmias
What are the side effects of Proton Pump inhibitors?
Constipation, D+, Nausea/V+, Skin rashes, Rugal hypertrophy (thickens the stomach wall). - BAD
How does Proton pump work?
- inhibits the H/K+ proton pump.
How does H2 receptor work?
- inhibits histamine action ->
What is mucosal protectors?
- Provides physical barrier over the ulcer.
What 3 drugs are a mucosal protectors?
- Sucralfate (Antepsin)
- BIsmth Chelate
- Misoprostol (Cytotec)
What are the properties of Sucralfate (Antepsin)?
- In presence of acid forms complex gels with mucus.
- Prevents degradation of mucus
- Stimulates mucosa protection mechanism.
- Oral
- Constipation, Dry mouth, V+, Rashes.
What are the properties of Bismuth Chelate?
- Coats ulcer base.
- Reduces prostaglandin synthesis (salucylate) - aspirin.
- Enhances bicarbonate production
- Very toxic to cats
What are the properties of Misoprostol (Cytotec)?
- Prostaglandin analogue
- Inhibits gastrin, stimulates mucus and bicarbonate.
- Oral
- Used to treat ulcers resulting from chronic NSAIDs use.
What are the properties of Cerenia?
- Licensed for dogs and cats
- inhibits the vomiting reflex.
- NK 1 receptor antagonist in medullary vomiting centre.
- Tx and prevention of V+, chemotherapy, motion sickness (high dose).
- SC/IV injection, oral tabs.
- Pain on SC injection common (refrigerate?).
- Not to be used >48hours without diagnosis
- Not to be used in cases of obstruction.
What are the properties of Cerenia?
- Licensed for dogs and cats
- inhibits the vomiting reflex.
- NK 1 receptor antagonist in medullary vomiting centre.
- Tx and prevention of V+, chemotherapy, motion sickness (high dose).
- SC/IV injection, oral tabs.
- Pain on SC injection common (refrigerate?).
- Not to be used >48hours without diagnosis.
- Not to be used in cases of obstruction.
- Good for analgesic for pancreatitis.
What are the properties of Metoclopramide? (Maxolon/Emeprid).
Acts at dopamine receptor (D2) in the chemoreceptor trigger zone in the medulla.
- Upper GI prokinetic
- Affects dopamine receptor elsewhere in CNS therefore a lot of side effects.
- Depression, nervousness, twitching, restlessness, (esp. cats may be disorientated).
- Not to be used in bowel obstruction.
- Oral tabs, syrup and injectable- IV/IM
What are the 3 types of Purgatives?
- Bulk and osmotic laxatives
- Faecal softeners
- Stimulant purgatives.
What are the bulk laxatives?
- Bran, Ispaghula, Sterculia. Retain water and promote peristalsis.
What are the osmotic laxatives?
lactulose. Maintain water in intestinal lumen by osmosis. Accelerates throughout.
What are the faecal softeners?
Docusate sodium - acts like a detergent to product soft faeces.
What are the stimulant purgatives?
- Increase water and electrolyte secretion and peristalsis.
- Micralax
- Bisacodyl - Suppository.
- Sodium picosulfate (Dulcolax) - given orally in prep for surgery/colonoscopy.
What are the stimulant purgatives?
- Increase water and electrolyte secretion and peristalsis.
- Micralax
- Bisacodyl - Suppository.
- Sodium picosulfate (Dulcolax) - given orally in prep for surgery/colonoscopy.
- Senna
What anti-diarrhoeals drugs are there?
Opiates such as morphine and codeine are highly effective in decreasing intestinal mobility. However, due to actions on other systems, they are rarely used.
Name the types of anti-diarrhoeals.
Loperamide (Imodium) - Antisecretory effect and reduce motility.
- Bismuth Subsalicylate
- Adsorbents - Kaolin, Pectin, Chalk, Charcoal, Magnesium Aluminium silicate. Adsorb micro-orgaisms? Alter intestinal flora? Coat and protect mucosa?
What drugs are used for inflammatory Bowel disease?
Glucocorticoids - anti-inflammatory.
Sulfasalazine (Salazopyrin) - acts as local ant-inflammatory in colon. Activated by colonic bacteria. Exact mechanisms of action unknown. Side effects - KCS (dry eyes), V+, Allergic, dermatitis.
Metronidazole used - Antibiotic.
What is Chemotherapy?
Drugs that inhibit mechanisms of cell proliferation.
- Kill rapidly dividing cells: higher proportion of malignant cells are dividing compared to normal tissues.
Identify the cell types that are mostly affected by chemotherapy?
Bone Marrow
- GI tract
- Skin, Hair Follicles
Identify the route by which chemotherapy drugs are administered?
IV/Oral
What are the side effects in patient receiving chemotherapy?
Fatigue, V+, Nausea, Reduced appetite, D+, Neutropaenia.
What are the side effects in patient receiving chemotherapy?
Fatigue, V+, Nausea, Reduced appetite, D+, Neutropaenia, alopecia