Ocular Pharm Mt 1: Local Anesthetics

1.

How do local anesthetics work?

A.

Increase potassium permeability, decreasing nerve threshold, slowing propagation of nerve impulses, reducing the rate of AP
B.

Reduce potassium permeability, increasing nerve threshold, slowing propagation of nerve impulses, reducing the rate of AP
C.

Increase sodium permeability, increasing nerve threshold, increasing propagation of nerve impulses, reducing the rate of AP
D.

Reduce sodium permeability, increasing nerve threshold, slowing propagation of nerve impulses, reducing the rate of AP

Correct Answer
D. Reduce sodium permeability, increasing nerve threshold, slowing propagation of nerve impulses, reducing the rate of AP

Explanation
Local anesthetics work by reducing sodium permeability, which means that they decrease the flow of sodium ions into the nerve cells. This in turn increases the nerve threshold, making it more difficult for the nerve to generate an action potential. By slowing the propagation of nerve impulses, local anesthetics effectively block the transmission of pain signals from reaching the brain, resulting in a reduction in the rate of action potentials and ultimately providing pain relief.

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2.

There is risk of cross reactivity between amide and ester local anesthetics.

A.

True
B.

False

Correct Answer
B. False

Explanation
No risk of cross reactivity between amides and esters

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3.

Esters have _ 'i' and amides have _ 'i'

Correct Answer
1, 2

Explanation
Esters have one 'i' and amides have two 'i'. This refers to the number of carbon atoms bonded to the oxygen atom in the functional group. In esters, there is one carbon atom bonded to the oxygen atom, while in amides, there are two carbon atoms bonded to the oxygen atom. This structural difference between esters and amides is what distinguishes them from each other.

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4

4.

Local anesthetics have realtively low systemic and oculary toxicty due to their sufficiently long duration of action, stability in solutio and minimal interference with the action of other drugs.

A.

True
B.

False

Correct Answer
A. True

Explanation
The statement is true because local anesthetics have low systemic and ocular toxicity. This is attributed to their long duration of action, stability in solution, and minimal interference with the action of other drugs.

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5.

Choose all the potential adverse affects for local anesthetics.

A.

CNS depression only
B.

CNS stimulation followed by CNS depression
C.

Potential respiratory depression
D.

Nausea/vomiting
E.

Delirum
F.

Convulsions
G.

Mydriasis
H.

Miosis
I.

CV collapse
J.

Insomnia

Correct Answer(s)
B. CNS stimulation followed by CNS depression
C. Potential respiratory depression
D. Nausea/vomiting
E. Delirum
F. Convulsions
G. Mydriasis
I. CV collapse

Explanation
mostly due to injectable forms

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6.

Local anesthetics are used to produce facial nerve block, retrobulbar/peribulbar anesthesia, and for eyelid infiltration.

A.

True
B.

False

Correct Answer
A. True

Explanation
Local anesthetics are commonly used in various procedures involving the face and eyes. Facial nerve block, retrobulbar/peribulbar anesthesia, and eyelid infiltration are all techniques that utilize local anesthetics to numb specific areas and reduce pain during procedures. Therefore, the statement that local anesthetics are used for these purposes is true.

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7.

What should dtermine the readiness for surgery when using a local anesthetic?

A.

Presence of akinesia
B.

Presence of corneal anesthesia

Correct Answer
A. Presence of akinesia

Explanation
When local anesthetics are used for retrobulbar block, complete corneal anesthesia usually precedes onset of clinically acceptable external ocular akinesia.. Therefore the presence of akinesia RATHER THn anesthesia alone should determine readiness for surgery.

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8.

Indicate the warning signs of serious cardiovascular reaction.

A.

Sweating
B.

Feeling faint
C.

Changes in pulse
D.

Changes in sensorium
E.

Vomitting

Correct Answer(s)
A. Sweating
B. Feeling faint
C. Changes in pulse
D. Changes in sensorium

Explanation
The warning signs of a serious cardiovascular reaction include sweating, feeling faint, changes in pulse, and changes in sensorium. Sweating is a common symptom of a cardiovascular issue as the body tries to regulate its temperature. Feeling faint can indicate a drop in blood pressure or inadequate blood flow to the brain. Changes in pulse, such as a rapid or irregular heartbeat, can be a sign of a cardiovascular problem. Changes in sensorium, which refers to alterations in consciousness or mental status, may occur due to reduced blood flow to the brain. Vomiting can also be a symptom of a cardiovascular reaction, although it is not specifically mentioned in the question.

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9.

What are the steps that should be taken if you suspect a patient may experience cardiovascular catastrophe?

10.

Local topical anesthetics stabalize neuronal membranes so the neuron is less permeable to ions, preventing the intiation and transmission of nerve impulses.

A.

True
B.

False

Correct Answer
A. True

Explanation
Limit sodium ion permeability, ultimately preventing generation of the AP

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11.

Tetracaine is much more potent than proparacaine. However, both have a reapid onset of anesthesia beginning within 10-30 seconds.

A.

True
B.

False

Correct Answer
B. False

Explanation
Proparacaine and tetracaine are equipotent. Both have a rapid onset of action within 10-30 sceonds following instillation in the eye.

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12.

Topical anesthetics should be used with caution in people with hypothyroidism

A.

True
B.

False

Correct Answer
B. False

Explanation
use with caution for people with hyperthyroidism

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13.

Ocular Pharm Mt 1: Local Anesthetics

How do local anesthetics work?

There is risk of cross reactivity between amide and ester local anesthetics.

Esters have ___ 'i' and amides have ___ 'i'

Local anesthetics have realtively low systemic and oculary toxicty due to their sufficiently long duration of action, stability in solutio and minimal interference with the action of other drugs.

Choose all the potential adverse affects for local anesthetics.

Local anesthetics are used to produce facial nerve block, retrobulbar/peribulbar anesthesia, and for eyelid infiltration.

What should dtermine the readiness for surgery when using a local anesthetic?

Indicate the warning signs of serious cardiovascular reaction.

What are the steps that should be taken if you suspect a patient may experience cardiovascular catastrophe?

Local topical anesthetics stabalize neuronal membranes so the neuron is less permeable to ions, preventing the intiation and transmission of nerve impulses.

Tetracaine is much more potent than proparacaine. However, both have a reapid onset of anesthesia beginning within 10-30 seconds.

Topical anesthetics should be used with caution in people with hypothyroidism

Describe the rare yet severe intermediate-type allergic corneal reaction to tetracaine and proparacaine.

Esters have _ 'i' and amides have _ 'i'