Drugs Flashcards
Do some drugs.
What is an example of a first generation antihistamine?
Chlorpheniramine
What sort of antihistamine is diphenhydramine?
First generation
Give an example of a second generation antihistamine
Loratadine
Name a drug that antagonises seratonin.
Metaclopramide
What other major molecule does metaclopramide antagonise?
Dopamine
Which drug is specifically a 5HT4 antagonist? Where is this receptor located?
Cisapride - located in the gut
Give an example of an SSRI
Fluoxetine
What does PGE2 do?
Pyrogen Promotes mucous secretion and inhibits acid secretion in the GI Contraction of pregnant uterus
What does PGF2alpha do? What is it used for in veterinary medicine?
Causes luteolysis Contraction of uterine muscle in parturition Used for synchornising oestrus in cattle, inducing abortion
What does Thromboxane A2 do?
Aggregation of platelets and vasoconstriction
A glucocorticoid with a moderately insoluble ester will have a _____ action. (long or short)
Longer
What is an Addisonian crisis and how could an animal have an ‘iatrogenic’ one?
It is a deficiency of glucocorticoids and mineralocorticoids. Could be precipitated by abrupt cessation of glucocorticoid therapy.
Name two immunosuppressant drugs that are often used in combination with glucocorticoids to treat autoimmune disease.
Azathioprine Cyclosporine
What is the mechanism of action of azathioprine?
Interferes with purine nucleotide synthesis and thence inhibits DNA synthesis and cell proliferation.
What are three side effects of azathioprine?
Myelosuppression so neutropenia, thrombocytopenia and anaemia, GI toxicity, hepatotoxicity
How would you monitor a patient on azathioprine for side effects?
CBC every 2 weeks to check for cytopenias, biochem every 2 weeks to check liver function
What is the mechanism of action of cyclosporine?
Complexes with calcineurin and thence inhibits IL-2 transcription and IFNgamma secretion so inhibits T cell activation and proliferation.
What is the generalised function of NSAIDs and how does this relate to the function of glucocorticoids?
Inhibit COX-1 and COX-2 More specific inhibitors of inflammation than GCCs, which inhibit both prostanoids and leukotrienes
What are the three big functions of NSAIDs?
- Antipyretic
- Analgesic
- Anti-inflammatory
What drug can you give to reduce the risk of NSAID-mediated GI ulceration?
Misoprostol
Give two examples of drugs that are marketed to target both COX1 and COX2.
Aspirin
Phenylbutazone
Give two examples of drugs that are marketed to target COX2 preferentially
Meloxicam
Carprofen
Give two examples of drugs that are marketed to target COX2 ONLY
Deracoxib
Mavacoxib
What are the two most common applications of NSAIDs in vet?
Osteoarthritis in cats and dogs
Post operative pain
Why are there only two NSAID products licensed for use in cats? What are they?
Because NSAIDs metabolised in the liver and cats have limited glucuronidation capacity, so the drug effects last longer
Meloxicam and robencoxib
If you have a patient who has been on glucocorticoids long-term, but they need mild pain relif, what are your two options?
- Taper the GCCs and wait for the washout period to be over before starting NSAIDs
- Start tapering the GCCs but start the NSAIDs anyway. Use misoprostol to mitigate the risk.
Give an example (brand name and drug name) of a disease-modifying osteoarthritis drug. Is it an NSAID?
Pentosan polysulfate (cartrophen)
NOT an NSAID
What is the mechanism of action for apoquel?
What is its application?
Inhibits JAK-1 dependent cytokines to control inflammation
Use in pruritis and allergic dermatitis
What are the 7 classes of chemotherapeutic drugs?
CHAT MAP
Cytotoxic antibiotics
Hormones
Alkylating agents
Tyrosine kinase inhibitors
Mitotic spindle inhibitors
Antimetabolites
Platinating agents
What is an example of a cytotoxic antibiotic and how does it work?
Doxorubicin
Inhibits toposiomerase II which is involved in DNA cleavage, unwinding and rejoining
Also intercalates DNA and therefore prevents DNA replication and thus cell division
What is an example of a hormone used in chemotherapy? How does it work?
High dose glucocorticoids
Lymphocytolytic; also increases appetite which is good
What is an example of an alkylating agent and how does it work?
Cyclophosphamide
Cross-links DNA to inhibit replication and cause cell apoptosis because DNA is damaged
Can also be immunosuppressive
What is a side effect of cyclophosphamide use?
Any of:
- myelosuppression
- alopecia
- sterile haemorrhagic cystitis
What is an example of a tyrosine kinase inhibitor? Why is this a good chemotherapeutic?
Toceranib (brand name Palladia)
TK receptors commonly upregulated in neoplasms and signalling via them promotes cellular growth and proliferation
What is an example of a mitotic spindle inhibitor? What parts of the cell cycle is this active at?
Vincristine
G2 and M
Give one side effect of vincristine.
Any of:
- peripheral neurotoxicity because neurons use tubulin, constipation, myelosuppression
What is an example of an anti-metabolite? How does it work?
Azathioprine
Homologue of normal cellular molecule - interferes with purine synthesis and therefore inhibits DNA synthesis
What is an example of a platinating agent and how does it work?
Cisplatin
Crosslinks in DNA by binding guanine residues therefore preventing replication and cell division
Give one side effect of cisplatin
Any of:
- nausea, vomiting, myelosuppression, renal toxicity due to drug being excreted this way and platinum deposition in glomeruli
