Ocular Pharm Mt 1: Local Anesthetics

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

True

False

Limit sodium ion permeability, ultimately preventing generation of the AP

Explanation

Limit sodium ion permeability, ultimately preventing generation of the AP

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

Presence of akinesia

Presence of corneal anesthesia

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.

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.

3. Match the procedure and the dosing of proparacaine HCL.

removal of sutures

tonometry

removal of FB

Proparacaine generic names: AK-Taine, Alcaine, Ophthetic, Parcain 0.5%

Explanation

Proparacaine generic names: AK-Taine, Alcaine, Ophthetic, Parcain 0.5%

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4. How do local anesthetics work?

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

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

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

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

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.

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.

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

True

False

No risk of cross reactivity between amides and esters

Explanation

No risk of cross reactivity between amides and esters

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

True

False

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

Explanation

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

7. 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.

True

False

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.

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.

8. Topical anesthetics should be used with caution in people with hypothyroidism

True

False

use with caution for people with hyperthyroidism

Explanation

use with caution for people with hyperthyroidism

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

True

False

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.

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.

10. Esters have ___ 'i' and amides have ___ 'i'

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.

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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11. Indicate the warning signs of serious cardiovascular reaction.

Sweating

Feeling faint

Changes in pulse

Changes in sensorium

Vomitting

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.

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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12. Choose all the potential adverse affects for local anesthetics.

CNS depression only

CNS stimulation followed by CNS depression

Potential respiratory depression

Nausea/vomiting

Delirum

Convulsions

Mydriasis

Miosis

CV collapse

Insomnia