A. Incorrect! Acetazolamide is a carbonic anhydrase inhibitor given orally or by intravenous injection.

Transcription

1 Pharmacology - Problem Drill 20: Drugs that Treat Glaucoma Question No. 1 of is a topical carbonic anhydrase inhibitor. Question #01 (A) Acetazolamide (B) Clonidine (C) Dorzolamide (D) Apraclonidine (E) Timolol Acetazolamide is a carbonic anhydrase inhibitor given orally or by intravenous injection. Clonidine is a sympathomimetic. C. Correct! Dorzolamide is a topical carbonic anhydrase inhibitor. Apraclonidine is an alpha-2 adrenoceptor agonist. Timolol is a beta blocker. Dorzolamide and brinzolamide are topical carbonic anhydrase inhibitors. They are used in patients resistant to beta-blockers or in whom beta-blockers are contraindicated. The correct answer is (C).

2 Question No. 2 of 10 Instructions: (1) Read the problem and answer choices carefully (2) Work the problems on paper as needed (3) Pick the answer (4) Go back to review the core concept tutorial as needed. 2. is an adrenergic neuron blocker that reduces aqueous secretion and is used either alone or in combination to enhance and prolong the effect of epinephrine. Question #02 (A) Sympathomimetics (B) Muscarinic agonists (C) Guanethidine (D) Epinephrine (E) Physostigmine Sympathomimetics produce papillary dilatation, thus they can induce an acute attack if used in angle-closure glaucoma. Muscarinic agonists facilitate trabecular drainage by constricting the pupil and pulling open the trabecular meshwork. Feedback on Each Answer C. Correct! Guanethidine, an adrenergic neuron blocker, reduces aqueous secretion and is used either alone or in combination to enhance and prolong the effect of epinephrine. Epinephrine can cause eye irritation and produce systemic effects. Physostigmine is rarely used to treat glaucoma. Guanethidine, an adrenergic neuron blocker, reduces aqueous secretion and is used either alone or in combination to enhance and prolong the effect of epinephrine; prolonged use can cause fibrosis and corneal changes. The correct answer is (C).

3 Question No. 3 of The greatest point of resistance to aqueous humour flow is the, which is also where most outflow occurs. Question #03 (A) Schlemm s canal (B) Trabecular meshwork (C) Uveoscleral drainage (D) Lens (E) Vitreous humour Schlemm s canal is just after this point of resistance. B. Correct! The greatest point of resistance to aqueous humour flow is the trabecular meshwork, which is also where most outflow occurs. A secondary, minor route of drainage is the uveoscleral drainage, which occurs independently of intraocular pressure. The lens does not impede aqueous humour flow. Vitreous humour does not impede aqueous humour flow. Aqueous humor is produced in the posterior chamber by the ciliary body, and flows out of the eye through the trabecular meshwork. After passing through the meshwork, the fluid drains into Schlemm s canal. The greatest point of resistance to aqueous flow is the trabecular meshwork, which is also where most outflow occurs. A secondary, minor route of drainage is the uveoscleral drainage, which occurs independently of intraocular pressure. The correct answer is (B).

4 Question No. 4 of is a prostaglandin analogue that increases the uveoscleral outflow. Question #04 (A) Physostigmine (B) Latanoprost (C) Pilocarpine (D) Acetazolamide (E) Guanethidine Physostigmine is not a prostaglandin analogue. B. Correct! Latanoprost is a prostaglandin analogue that increases the uveoscleral outflow. Pilocarpine is not a prostaglandin analogue. Acetazolamide is a carbonic anhydrase inhibitor. Guanethidine is an adrenergic neuron blocker. Latanoprost and travoprost are prostaglandin analogues that increase the uveoscleral outflow. The correct answer is (B).

5 Question No. 5 of facilitate trabecular drainage by constricting the pupil and pulling open the trabecular meshwork. Question #05 (A) Sympathomimetics (B) Muscarinic agonists (C) Guanethidine (D) Epinephrine (E) Physostigmine Sympathomimetics produce papillary dilatation, thus they can induce an acute attack if used in angle-closure glaucoma. B. Correct! Muscarinic agonists facilitate trabecular drainage by constricting the pupil and pulling open the trabecular meshwork. Guanethidine, an adrenergic neuron blocker, reduces aqueous secretion and is used either alone or in combination to enhance and prolong the effect of epinephrine. Epinephrine can cause eye irritation and produce systemic effects. Physostigmine is rarely used to treat glaucoma. Muscarinic agonists facilitate trabecular drainage by constricting the pupil and pulling open the trabecular meshwork. The correct answer is (B).

6 Question No. 6 of is converted into epinephrine by corneal esterases. Question #06 (A) Physostigmine (B) Clonidine (C) Dipivefrine (D) Latanoprost (E) Acetazolamide Physostigmine is not converted into epinephrine by corneal esterases. Clonidine is not converted into epinephrine by corneal esterases. C. Correct! Dipivefrine is converted into epinephrine by corneal esterases. Latanoprost is a prostaglandin analogue. Acetazolamide is a carbonic anhydrase inhibitor. Epinephrine can cause eye irritation and produce systemic effects; it is now rarely used. Dipivefrine is converted into epinephrine by corneal esterases and ocular adverse effects are usually less than with epinephrine itself. The correct answer is (C).

7 Question No. 7 of Closed angle glaucoma: Question #07 (A) Can appear suddenly. (B) Is often painful. (C) Is associated with a shallow anterior chamber. (D) Can be prevented by surgical removal of the iris. (E) All of the above This is not the only characteristic of closed angle glaucoma. This is not the only characteristic of closed angle glaucoma. This is not the only characteristic of closed angle glaucoma. This is not the only characteristic of closed angle glaucoma. E. Correct! All of the answers are correct. Closed angle glaucoma can appear suddenly and is often painful. It is associated with a shallow anterior chamber in which a dilated iris blocks the outflow of the fluid. Visual loss can progress quickly but the discomfort often leads patients to seek medical attention before permanent damage occurs. Closed angle glaucoma can be prevented by surgical removal of the iris. The correct answer is (E).

8 Question No. 8 of A class of drugs used to treat open angle glaucoma is: Question #08 (A) Cholinomimetics (B) Muscarinic agonsts (C) Prostaglandins (D) Diuretics (E) All of the above This is not the only class of drugs used to treat open angle glaucoma. This is not the only class of drugs used to treat open angle glaucoma. This is not the only class of drugs used to treat open angle glaucoma. This is not the only class of drugs used to treat open angle glaucoma. E. Correct! All of the answers are correct. The five groups of drugs that are used in the pharmacological treatment of open angle glaucoma include cholinomimetics, α-agonists, muscarinic agonists, prostaglandins and diuretics. These drugs work by either increasing outflow or decreasing secretion of the fluid. The correct answer is (E).

9 Question No. 9 of The following treatments of open angle glaucoma increase outflow: Question #09 (A) α agonists (B) Muscarinic agonists (C) Prostaglandins (D) All of the above (E) None of the above This is not the only class of drugs that increases outflow. This is not the only class of drugs that increases outflow. This is not the only class of drugs that increases outflow. D. Correct! All of the answers are correct. One of the above answers is correct. Treatments that increase outflow in open angle glaucoma include: α-agonists Epinephrine Muscarinic agonists (cholinomimetics) Pilocarpine, physostigmine, echothiophate Prostaglandins Latanoprost The correct answer is (D).

10 Question No. 10 of 10 Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as 10. Treatments that decrease secretion of aqueous humor include: Question #10 (A) β blockers (B) α2 agonists (C) Carbonic acid inhibitors (D) All of the above (E) None of the above This is not the only class of drugs that decrease secretion of aqueous humor. This is not the only class of drugs that decrease secretion of aqueous humor. This is not the only class of drugs that decrease secretion of aqueous humor. D. Correct! All of these drug classes decrease secretion of aqueous humor. One of the above answers is correct. Treatments that decrease secretion of aqueous humor include: β blockers Timolol, betaxolol, carteolol α2 agonists Apraclonidine Carbonic acid inhibitors (diuretics) Acetazolamide, methazolamide, dorzolamide, brinzolamide The correct answer is (D).