Ocular med

Question 1

agents that release drugs by diffusion following erosion of soluble polymers.

Answer 1

Opthalmic gels

Question 2

usually contain mineral oil and a petrolatum base.

Answer 2

Ointments

Question 3

They are helpful in delivering antibiotics, cycloplegic drugs, or miotic agents.

Answer 3

Ointments

Question 4

provide a zero-order rate of delivery by steady-state diffusion, whereby the drug is released at a more constant rate over a prolonged period of time rather than as a bolus

Answer 4

Solid inserts

Question 5

are made of soft, flexible plastics that allow oxygen to pass through to the cornea and may carry medications along with it.

Answer 5

Soft contact lenses

Question 6

are developed as a corneal bandage lens and are currently indicated for ocular surface protection following surgery and in traumatic and nontraumatic corneal conditions.

Answer 6

Collagen shields

Question 7

Six Ocular routes of drug administration

Answer 7

topical, subconjunctival, sub-Tenon, and retrobulbar injections, intraocular/intracameral injections, and intravitreal injections.

Question 8

This route includes administration of topical agents such as ointments, creams, and other similar preparations directly into the eye surface.

Answer 8

Topical administration

Question 9

• It has a prompt absorption pattern relative to its preparation (Route)

Answer 9

Topical administration

Question 10

• It is convenient, economical, and relatively safe, however, may cause mucosal
  irritation. (Route)

Answer 10

Topical administration

Question 11

• It has prompt absorption and is used for anterior segment surgery and infections.

Answer 11

Intraocular/Intracameral Injection

Question 12

It has a relatively short duration of action and may cause intraocular toxicity.

Answer 12

Intraocular/Intracameral Injection

Question 13

It refers to the administration of agents into the vitreous cavity of the eye.

Answer 13

Intravitreal injection

Question 14

It circumvents absorption and displays immediate local and potential sustained effect

Answer 14

Intravitreal Injection

Question 15

Intravitreal injection

Answer 15

• It is used in conditions such as retinitis, but may also cause retinal toxicity.

Question 16

What are the factors affecting absorption to systemic circulation include:

Answer 16

a. Precorneal fluid drainage
b. Drug binding to tear proteins
c. Systemic drug absorption
d. Corneal factors
e. Melanin binding
f. Drug metabolism

Question 17

This is the main reason for low ocular drug absorption

Answer 17

Precorneal fluid drainage

Question 18

may result in a reduction in concentration of total available free drug for required pharmacological action at target site.

Answer 18

Drug binding to tear proteins

Question 19

It is nonproductive due to the presence of conjunctival capillaries and lymphatics causing significant drug loss into the systemic circulation decreasing drug bioavailability.

Answer 19

Systemic drug absorption

Question 20

• The epithelial layer of the cornea is lipoidal in nature and the stroma is hydrophilic, thus affecting the absorption of drug relative to its composition.

Answer 20

Corneal factors

Question 21

The melanin pigment present in the iris and the ciliary body may also change the ocular bioavailability of a topically administered drug.

Answer 21

Melanin binding

Question 22

Enzymes such as CYP P450, aldehyde oxidase, hydrolase, transferase, and monoamine oxidase, are expressed in the ocular tissues and metabolized the ocular drug leading to decreased bioavailability.

Answer 22

Drug metabolism

Question 23

It inhibits RnA-dependent protein synthesis by binding to the 50s ribosomal subunit, preventing the translocation of peptide chains.

Answer 23

Azithromycin

Question 24

It inhibits bacterial cell wall synthesis by preventing transfer of mucopeptides into the growing cell wall and damages bacterial plasma membrane and active against protoplasts

Answer 24

Bacitracin

Question 25

acts by inhibiting DNA synthesis in susceptible organisms via inhibition of both topoisomerase IV and DNA gyrase, inhibiting bacterial reproduction and bacterial cell division.

Answer 25

Besifloxacin

Question 26

It inhibits bacterial protein synthesis by binding to 50s subunit of the bacterial ribosome, thus preventing peptide bond formation by peptidyl transferase.

Answer 26

Chloramphenicol

Question 27

It acts by inhibiting DNA gyrase and topoisomerase IV, both essential in bacterial DNA replication, transcription, repair and recombination

Answer 27

Ciprofloxacin

Question 28

It inhibits protein synthesis by irreversibly binding to the 50S ribosomal subunit thus blocking the transpeptidation or translocation reactions of susceptible organisms resulting in stunted cell growth.

Answer 28

Erythromycin

Question 29

It acts by inhibiting DNA synthesis in susceptible organisms via inhibition of both DNA gyrase and topoisomerase IV, causing inhibitiom of bacterial reproduction and bacterial cell division.

Answer 29

Gatifloxacin

Question 30

It interferes w/ bacterial protein synthesis by binding to 30S and 50S ribosomal subunits resulting in a defective bacterial cell membrane.

Answer 30

Gentamicin

Question 31

It inhibits bacterial topoisomerase IV and DNA- gyrase, the enzymes required for DNA replication, transcription, repair, recombination and transposition, thereby inhibiting the relaxation of supercoiled DNA and promoting breakage of bacterial DNA strands.

Answer 31

LEVOFLOXACIN

Question 32

It inhibits bacterial topoisomerase IV and DNA gyrase (topoisomerase II) enzymes which are essential for bacterial DNA replication, transcription, repair and recombination thereby impeding bacterial growth

Answer 32

Moxifloxacin

Question 33

it inhibits bacterial topoisomerase IV and DNA gyrase enzymes required for DNA replication, transcription, repair, transposition and recombination.

Answer 33

Ofloxacin

Question 34

It interferes with nucleic acid synthesis thus blocking conversion of PABA to the coenzyme dihydrofolic acid.

Answer 34

Sulfacetamide

Question 35

It disrupts the bacterial cytoplasmic membrane of mostly gram negative organisms allowing leakage of intracellular constituents by binding to membrane phospholipids.

Answer 35

Polymixin B combination

Question 36

It interferes with bacterial protein synthesis by binding 30S and 50s ribosomal subunits, resulting in a defective bacterial cell membrane.

Answer 36

Tobramycin