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56 Cards in this Set
- Front
- Back
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Define what is an agonist and what is the difference between a full, partial and inverse agonist |
A full agonist is a ligand that maximally (100%) binds to a receptor and produces and maximal effect. EC50 = 100% for affinity. Emax = 100% for Efficacy. A partial agonist maximally binds to a receptor and produces a submaximal |
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Give examples of Antimuscarinics and their mechanism of action on the eye.
Hint: Muscarinic receptors (B2) regulate contraction of _____ muscle |
Atropine, Homatropine, Cyclopentolate and Tropicamide. Antimuscarinics have a mydriatic effect on the eye. They act by relaxing the ciliary muscle (b2 muscarinic receptor) responsible for accommodation and stretch the suspensory ligaments. The stretching of the lens becomes flatter, focused for far vision. This causes cycloplegia |
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What is cycloplegia? |
Inability of the lens to adjust to near vision |
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What are the common adverse effects of Antimuscarinics? What are some precautions?
Hint: What effects do muscarinic receptors produce? |
- Blurred vision - Systemic absorption - dry mouth, tachycardia, dizziness, constipation (Opposite of DUMBELS) - Elevation of IOP (C/I in narrow angle glaucoma) - Precaution: Do not drive, wear dark glasses, Close eyes after instillation
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What are examples of Sympathomimetics and what is the mechanism of action of these drugs?
Hint: 'mimic' sympathetic system |
Phenylephrine, Naphazoline, Tetrahydrozoline. Act on the alpha 1 receptor on the radial muscle to cause pupil dilation (my |
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Define what is an agonist and what is the difference between a full, partial and inverse agonist
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A full agonist is a ligand that maximally (100%) binds to a receptor and produces and maximal effect. EC50 = 100% for affinity. Emax = 100% for Efficacy. A partial agonist maximally binds to a receptor and produces a submaximal
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Give examples of Antimuscarinics and their mechanism of action on the eye.Hint: Muscarinic receptors (B2) regulate contraction of _____ muscle
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Atropine, Homatropine, Cyclopentolate and Tropicamide. Antimuscarinics have a mydriatic effect on the eye. They act by relaxing the ciliary muscle (b2 muscarinic receptor) responsible for accommodation and stretch the suspensory ligaments. The stretching of the lens becomes flatter, focused for far vision. This causes cycloplegia
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What is cycloplegia?
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Inability of the lens to adjust to near vision due to paralysis of the ciliary muscle of the eye. The ciliary muscle has muscarinic intervention.
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What are the common adverse effects of Antimuscarinics? What are some precautions? Hint: What effects do muscarinic receptors produce?
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Blurred vision, Systemic absorption, dry mouth, tachycardia, dizziness, constipation (Opposite of DUMBELS), Elevation of IOP (C/I in narrow angle glaucoma) Precaution: Do not drive, wear dark glasses, Close eyes after instillation
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What are examples of Sympathomimetics and what is the mechanism of action of these drugs? Do they cause Cyclopegia? Hint: Ciliary muscle has muscarinic intervention Hint: 'mimic' sympathetic system
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Phenylephrine, Naphazoline, Tetrahydrozoline. Act on the alpha 1 receptor on the radial muscle to cause pupil dilation (mydriasis). There is also a decrease in congestion of blood vessels and a decrease in aqueous humour. Thus, acting as ocular decongestants. They do not produce Cyclopegia.
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What are common adverse reactions and precautions of Sympathomimetics?
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Vasoconstriction causes increase PVR, increasing BP. Tachycardia, Anxiety. Precautions: hypertension, heart disease, thyrotoxicosis. C/I in closed angle glaucoma
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What are examples of Miotics and how do they work?
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Acetylcholine, Pilocarpine and Carbachol are muscarinic agents that act as miotics. They contract the ciliary muscle for accomodation causing relaxation of suspensory ligaments and the lens. The bulged lens decrease focal length, this is focused for near vision.
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What are common adverse effects of Miotics? What is the indication?
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Effects are ocular, causing pupil constriction (miosis), accommodation spasm causing myopia and loss of visual acuity, dilation of conjunctival and uveal blood vessels causing hyperaemia (retinal detachment).Indicated for glaucoma and reverse the effects of mydriatics.
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What is Glaucoma?
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Primary Open Angle Glaucoma (POAG) is where the angle between the iris and the cornea is normal, but the drainage holes get clogged from the inside.Closed Angle Glaucoma is where the angle is narrower than normal. If fluid cannot flow easily through the opening in the pupil, the iris pushes forward and blocks the drainage holes.
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How is Glaucoma characterised?
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By increased IOP. The normal range is 10-15mmHg and Glaucoma is >21mmHg. There is impaired vision (loss of peripheral vision, loss of visual acuity and blindness)
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What are the topical drugs for open angle Glaucoma?
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First line: Prostaglandin analogues (-prost): Increases aq outflow. Most effective.Beta-blockers (betaxolol, timolol): Decreases aq production. Avoid in asthma Second line: Alpha 2 agonists (-idine): Increase outflow, decrease production. CA inhibitors (-zolamide): Decrease production Rarely Used: Cholinergic (pilocarpine): Increase outflow
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B-Blockers in Glaucoma
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Sympathomimetic Agents in GlaucomaProstaglandin Analogues for Glaucoma Carbonic Anhydrase Inhibitors for Glaucoma
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Describe the importance of the serotoninergic pathway
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Cell bodies in raphe nucleus. Synthesis starts at Tryptophan (in diet) and is hydroxilised by Tryptophan Hydroxylase into 5-Hydroxytryptophan. This is converted to 5-Hyroxytryptamine (5-HT/Serotonin) by the enzyme dopa decarboxylase. It is broken down by monoamine oxidase and aldehyde dehydrogenase. |
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Define what is an agonist and what is the difference between a full, partial and inverse agonist
|
A full agonist is a ligand that maximally (100%) binds to a receptor and produces and maximal effect. EC50 = 100% for affinity. Emax = 100% for Efficacy. A partial agonist maximally binds to a receptor and produces a submaximal
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Give examples of Antimuscarinics and their mechanism of action on the eye.Hint: Muscarinic receptors (B2) regulate contraction of _____ muscle
|
Atropine, Homatropine, Cyclopentolate and Tropicamide. Antimuscarinics have a mydriatic effect on the eye. They act by relaxing the ciliary muscle (b2 muscarinic receptor) responsible for accommodation and stretch the suspensory ligaments. The stretching of the lens becomes flatter, focused for far vision. This causes cycloplegia
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What is cycloplegia?
|
Inability of the lens to adjust to near vision due to paralysis of the ciliary muscle of the eye. The ciliary muscle has muscarinic intervention.
|
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What are the common adverse effects of Antimuscarinics? What are some precautions? Hint: What effects do muscarinic receptors produce?
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Blurred vision, Systemic absorption, dry mouth, tachycardia, dizziness, constipation (Opposite of DUMBELS), Elevation of IOP (C/I in narrow angle glaucoma) Precaution: Do not drive, wear dark glasses, Close eyes after instillation
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What are examples of Sympathomimetics and what is the mechanism of action of these drugs? Do they cause Cyclopegia? Hint: Ciliary muscle has muscarinic intervention Hint: 'mimic' sympathetic system
|
Phenylephrine, Naphazoline, Tetrahydrozoline. Act on the alpha 1 receptor on the radial muscle to cause pupil dilation (mydriasis). There is also a decrease in congestion of blood vessels and a decrease in aqueous humour. Thus, acting as ocular decongestants. They do not produce Cyclopegia.
|
|
|
What are common adverse reactions and precautions of Sympathomimetics?
|
Vasoconstriction causes increase PVR, increasing BP. Tachycardia, Anxiety. Precautions: hypertension, heart disease, thyrotoxicosis. C/I in closed angle glaucoma
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What are examples of Miotics and how do they work?
|
Acetylcholine, Pilocarpine and Carbachol are muscarinic agents that act as miotics. They contract the ciliary muscle for accomodation causing relaxation of suspensory ligaments and the lens. The bulged lens decrease focal length, this is focused for near vision.
|
|
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What are common adverse effects of Miotics? What is the indication?
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Effects are ocular, causing pupil constriction (miosis), accommodation spasm causing myopia and loss of visual acuity, dilation of conjunctival and uveal blood vessels causing hyperaemia (retinal detachment).Indicated for glaucoma and reverse the effects of mydriatics.
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What is Glaucoma?
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Primary Open Angle Glaucoma (POAG) is where the angle between the iris and the cornea is normal, but the drainage holes get clogged from the inside.Closed Angle Glaucoma is where the angle is narrower than normal. If fluid cannot flow easily through the opening in the pupil, the iris pushes forward and blocks the drainage holes.
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How is Glaucoma characterised?
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By increased IOP. The normal range is 10-15mmHg and Glaucoma is >21mmHg. There is impaired vision (loss of peripheral vision, loss of visual acuity and blindness)
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What are the topical drugs for open angle Glaucoma?
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First line: Prostaglandin analogues (-prost): Increases aq outflow. Most effective.Beta-blockers (betaxolol, timolol): Decreases aq production. Avoid in asthma Second line: Alpha 2 agonists (-idine): Increase outflow, decrease production. CA inhibitors (-zolamide): Decrease production Rarely Used: Cholinergic (pilocarpine): Increase outflow
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B-Blockers in Glaucoma
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Sympathomimetic Agents in GlaucomaProstaglandin Analogues for Glaucoma Carbonic Anhydrase Inhibitors for Glaucoma
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Describe the importance of the serotoninergic pathway
|
Cell bodies in raphe nucleus. Synthesis starts at Tryptophan (in diet) and is hydroxilised by Tryptophan Hydroxylase into 5-Hydroxytryptophan. This is converted to 5-Hyroxytryptamine (5-HT/Serotonin) by the enzyme dopa decarboxylase. It is broken down by monoamine oxidase and aldehyde dehydrogenase.
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Define what is an agonist and what is the difference between a full, partial and inverse agonist
|
A full agonist is a ligand that maximally (100%) binds to a receptor and produces and maximal effect. EC50 = 100% for affinity. Emax = 100% for Efficacy. A partial agonist maximally binds to a receptor and produces a submaximal
|
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Give examples of Antimuscarinics and their mechanism of action on the eye.Hint: Muscarinic receptors (B2) regulate contraction of _____ muscle
|
Atropine, Homatropine, Cyclopentolate and Tropicamide. Antimuscarinics have a mydriatic effect on the eye. They act by relaxing the ciliary muscle (b2 muscarinic receptor) responsible for accommodation and stretch the suspensory ligaments. The stretching of the lens becomes flatter, focused for far vision. This causes cycloplegia
|
|
|
What is cycloplegia? |
Inability of the lens to adjust to near vision due to paralysis of the ciliary muscle of the eye. The ciliary muscle has muscarinic intervention. |
|
|
What are the common adverse effects of Antimuscarinics? What are some precautions? Hint: What effects do muscarinic receptors produce?
|
Blurred vision, Systemic absorption, dry mouth, tachycardia, dizziness, constipation (Opposite of DUMBELS), Elevation of IOP (C/I in narrow angle glaucoma) Precaution: Do not drive, wear dark glasses, Close eyes after instillation
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What are examples of Sympathomimetics and what is the mechanism of action of these drugs? Do they cause Cyclopegia? Hint: Ciliary muscle has muscarinic intervention Hint: 'mimic' sympathetic system
|
Phenylephrine, Naphazoline, Tetrahydrozoline. Act on the alpha 1 receptor on the radial muscle to cause pupil dilation (mydriasis). There is also a decrease in congestion of blood vessels and a decrease in aqueous humour. Thus, acting as ocular decongestants. They do not produce Cyclopegia.
|
|
|
What are common adverse reactions and precautions of Sympathomimetics?
|
Vasoconstriction causes increase PVR, increasing BP. Tachycardia, Anxiety. Precautions: hypertension, heart disease, thyrotoxicosis. C/I in closed angle glaucoma
|
|
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What are examples of Miotics and how do they work?
|
Acetylcholine, Pilocarpine and Carbachol are muscarinic agents that act as miotics. They contract the ciliary muscle for accomodation causing relaxation of suspensory ligaments and the lens. The bulged lens decrease focal length, this is focused for near vision.
|
|
|
What are common adverse effects of Miotics? What is the indication?
|
Effects are ocular, causing pupil constriction (miosis), accommodation spasm causing myopia and loss of visual acuity, dilation of conjunctival and uveal blood vessels causing hyperaemia (retinal detachment).Indicated for glaucoma and reverse the effects of mydriatics.
|
|
|
What is Glaucoma?
|
Primary Open Angle Glaucoma (POAG) is where the angle between the iris and the cornea is normal, but the drainage holes get clogged from the inside.Closed Angle Glaucoma is where the angle is narrower than normal. If fluid cannot flow easily through the opening in the pupil, the iris pushes forward and blocks the drainage holes.
|
|
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How is Glaucoma characterised?
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By increased IOP. The normal range is 10-15mmHg and Glaucoma is >21mmHg. There is impaired vision (loss of peripheral vision, loss of visual acuity and blindness)
|
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What are the topical drugs for open angle Glaucoma?
|
First line: Prostaglandin analogues (-prost): Increases aq outflow. Most effective.Beta-blockers (betaxolol, timolol): Decreases aq production. Avoid in asthma Second line: Alpha 2 agonists (-idine): Increase outflow, decrease production. CA inhibitors (-zolamide): Decrease production Rarely Used: Cholinergic (pilocarpine): Increase outflow
|
|
|
B-Blockers in Glaucoma
|
Sympathomimetic Agents in GlaucomaProstaglandin Analogues for Glaucoma Carbonic Anhydrase Inhibitors for Glaucoma
|
|
|
Describe the importance of the serotoninergic pathway
|
Cell bodies in raphe nucleus. Synthesis starts at Tryptophan (in diet) and is hydroxilised by Tryptophan Hydroxylase into 5-Hydroxytryptophan. This is converted to 5-Hyroxytryptamine (5-HT/Serotonin) by the enzyme dopa decarboxylase. It is broken down by monoamine oxidase and aldehyde dehydrogenase.
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Serotonin Synapse and receptors 5HT Receptors. Which of the receptors are the GPCR?
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All 5-HT receptors are GPCR except 5-HT3 which is a ligand gated cation channel
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Buspirone: What receptor does the drug act on? What are the main functions of the receptor? Does it act as an agonist or an antagonist? What is the signal transduction pathway?
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Agonist for 5-HT1A receptor in the CNS, which is responsible for neural inhibition of behavioural effects such as anxiety and depression. As well as sleep, feeding and thermoregulation Gi --> -AC --> decrease cAMP
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Ergotamine What receptor does the drug act on? What are the main functions of the receptor? Does it act as an agonist or an antagonist?
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Acts as an agonist for 5-HT1B in CNS and vascular smooth muscles. Receptor is involved in presynaptic inhibition
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5-HT1D. Example of an agonist and its effect?
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5-HT1D acts on the CNS and blood vessels. An agonist (Triptans) causes cerebral vasoconstriction (migraine)
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Receptor 5-HT3: Location, main functions, signal transduction. What are drugs that act on this receptor?
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Located in the PNS and CNS, it serves as a neuronal excitation causing behavioural effects such as anxiety and emesis. It is the only ligand gated ion channel amongst the serotonin receptors. Dolesatron, Granisetron, Ondansetron, Palonosetron and Tropisetron act as antagonists.
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5-HT4 receptors Location, main functions, signal transduction. What are drugs that act on this receptor?
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Location is in the CNS and PNS including GI tract. It serves as neuronal excitation and GI motility. The G protein Gs is involved which increased cAMP. The drugs that act as agonists are Metoclopramide, Cisapride, and Tegaserod.
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What are the three classes of Antidepressants?
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Tricyclic anti-depressants (-pramine) block reuptake of monoamines by competing for the binding site on the carrier protein Selective serotonin reuptake inhibitors (SSRIs) e.g Fluoxetine and Monoamine Oxidase inhibitors (MAOIs) *MAO are low in depression. Inhibit = Decrease breakdown of 5-HT and increase levels 5-HT
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What are the adverse effects of Antidepressants?
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?? |
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Summarise the actions of the receptor 5-HT1
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5-HT1: Inhibits AC, Neuronal inhibition, vasoconstriction. 1A = Anxiety/Depression 1D = Migraine |
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Summarise the actions of the receptor 5-HT2 |
5-HT2: CNS and periphery (blood vessels, platelets, ANS). Stimulates PLC, neuronal and smooth muscle excitation, migraine, hallucinations and CV effects
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Summarise the actions of the receptor 5-HT3
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5-HT3: PNS, excitatory, enteric nervous system, nausea/vomiting
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Summarise the actions of the receptor 5-HT4
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5-HT4: Enteric nervous system, excitatory, stimulates AC, prokinetic (GIT) |
