Ocular Chloramphenicol and Aplastic Anemia Association

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Which drug combination is most likely to increase the risk of QT prolongation and cardiac arrhythmias?

Warfarin and statins

Warfarin and antacids

Azithromycin and antacids

Azithromycin and statins (correct)

In the context of meibomian gland dysfunction, which antibiotic is highlighted for its anti-inflammatory effects?

Iodaron

Sotalol

Quinidine

Azithromycin (correct)

When comparing azithromycin and doxycycline in the treatment of meibomian gland dysfunction, which property differentiates doxycycline from azithromycin?

Antimicrobial effect

Anti-inflammatory effect

Metalloproteinase inhibition (correct)

Topical application

Which antibiotic is mentioned to have fewer side effects compared to tetracycline in the text?

Doxycycline Signup and view all the answers

Considering the potential drug interactions mentioned, which medication combination is warned about due to the increased risk of bleeding?

Warfarin and azithromycin Signup and view all the answers

What is the main impact of macrolides on bacterial cells?

Inhibition of bacterial protein synthesis Signup and view all the answers

Which of the following is NOT a clinical use of macrolides mentioned in the text?

Meibomian gland dysfunction Signup and view all the answers

For which condition is erythromycin ophthalmic ointment specifically used?

Superficial bacterial ocular infection Signup and view all the answers

What is a notable difference between azithromycin and doxycycline in treating urogenital Chlamydia infections?

Doxycycline is more effective for rectal infections in both men and women. Signup and view all the answers

What is a key consideration regarding the use of Azithromycin's Zmax extended-release suspension/liquid?

Must be taken with food to increase its effectiveness. Signup and view all the answers

What did the systematic review mentioned in the text conclude about azithromycin and doxycycline in the treatment of Meibomian Gland Dysfunction?

Azithromycin is a good alternative to doxycycline based on the reviewed studies. Signup and view all the answers

Which statement accurately reflects the findings of the systematic review regarding azithromycin and doxycycline?

Azithromycin has better safety and efficacy than doxycycline in treating Meibomian Gland Dysfunction. Signup and view all the answers

What is one of the advantages of using azithromycin over doxycycline according to the text?

Azithromycin has a broader spectrum of activity than doxycycline. Signup and view all the answers

In terms of protein synthesis, what effect does chloramphenicol have according to the text?

Chloramphenicol blocks protein synthesis by binding to the 50s ribosomal subunit. Signup and view all the answers

What side effect is associated with chloramphenicol use as mentioned in the text?

Aplastic anemia Signup and view all the answers

Which antibiotic is recommended for its better effect on improving the signs and overall clinical response in Meibomian Gland Dysfunction?

Oral Azithromycin Signup and view all the answers

In a randomized double-masked trial comparing oral Azithromycin and Doxycycline in Meibomian Gland Dysfunction, which group showed statistically significant better sign scores?

Oral Azithromycin group Signup and view all the answers

Which antibiotic was found to have lower cost and fewer side effects compared to the other in the treatment of Meibomian Gland Dysfunction?

Oral Azithromycin Signup and view all the answers

Which form of Azithromycin was used in the intervention comparing it to Doxycycline, according to the study?

1g once per week Signup and view all the answers

Which antibiotic was noted to control bacteria while also being valued for its anti-inflammatory effects in the context of decreasing inflammation and MMP9 effect?

Doxycycline Signup and view all the answers

What is the mechanism by which aplastic anemia is induced by chloramphenicol?

Chloramphenicol triggers cytotoxic effects in bone marrow cells Signup and view all the answers

Why was the use of Bacillus anthracis (anthrax) discontinued in the US?

Due to its association with aplastic anemia Signup and view all the answers

What is the role of intestinal bacteria in the metabolism of chloramphenicol?

Intestinal bacteria convert chloramphenicol into dehydrochloramphenicol Signup and view all the answers

What contributes to the increased cytotoxicity on DNA exhibited by derivatives of chloramphenicol?

Greater capacity of host marrow to generate toxic intermediates Signup and view all the answers

What is the main concern associated with systemic use of chloramphenicol in infants?

Systemic toxicity Signup and view all the answers

What is the estimated risk of developing aplastic anemia after topical use of chloramphenicol?

Less than one in a million treatment courses Signup and view all the answers

Based on the text, what is suggested as an alternative when there is resistance to fluoroquinolones?

Topical chloramphenicol in select cases Signup and view all the answers

What mechanism is proposed as a cause of aplastic anemia related to ocular chloramphenicol administration?

Conversion of chloramphenicol into dehdyrochloramphenicol by gut bacteria Signup and view all the answers

In what scenario might using chloramphenicol be considered despite the risk of aplastic anemia?

When a patient has vision-threatening keratitis that failed first-line antibiotic drops Signup and view all the answers

What class of antibiotics is mentioned as affecting intermediary metabolism along with sulfonamides and trimethoprim?

Folic Acid Signup and view all the answers

Which stage of the cycle do sulfa drugs come in to affect nucleic acid synthesis?

Early stage Signup and view all the answers

What is the effect of trimethoprim on the DHFR enzyme?

Inhibits it Signup and view all the answers

Which bacteria are sulfonamides effective against?

Both Gram-positive and Gram-negative bacteria Signup and view all the answers

What is the main target of trimethoprim among the cellular components?

Dihydrofolate reductase (DHFR) enzyme Signup and view all the answers

What is the role of pteridine and PABA in the metabolic cycle discussed?

Initiate the cycle Signup and view all the answers

How do trimethoprim and methotrexate differ in their action on the metabolic cycle?

Trimethoprim inhibits DHFR earlier than methotrexate Signup and view all the answers

What effect do sulfa drugs have on nucleic acid synthesis in bacteria?

Inhibit synthesis Signup and view all the answers

Which cellular component is targeted by pyrimethamine among the options provided?

"Tetrahydrofolate" Signup and view all the answers

When considering antibiotics in intermediary metabolism, where do sulfa drugs come into play?

At the beginning of the cycle Signup and view all the answers

What is the main impact of trimethoprim on dihydrofolate reductase (DHFR)?

Inhibition of DHFR enzyme Signup and view all the answers