lec 7-2026 record

The typical QT interval is highlighted in blue and shows a normal length, while the prolonged QT interval is highlighted in red and is longer.

They inhibit bacterial RNA polymerase, blocking the elongation of the nascent mRNA molecule.

It is usually used in combination with other agents to prevent the emergence of resistant strains and for the treatment of mycobacterial infections.

It causes an orange-red discoloration of tears, urine, and other body fluids.

It is an antiprotozoal drug with antibacterial effects on anaerobic bacteria.

It causes damage to DNA.

It is limited to obligate anaerobic bacteria.

It is reduced to toxic intermediate compounds that can interfere with enzymes in DNA, RNA, and protein synthesis.

It has activity against many organisms that commonly cause urinary tract infections, including aerobic Gram-negative bacteria (except proteus spp. and P. aeruginosa) and aerobic Gram-positive bacteria.

Because it is concentrated in urine.

-mycin

-micin

Irreversible binding to the 30S subunit causing inhibition of initiation and misreading of mRNA by ribosomes.

Bactericidal.

Streptomycin, Gentamicin, Tobramycin, Neomycin, or Amikacin.

Parenteral administration (IV, IM) and topical application.

Aerobic Gram-negative bacteria, including Enterobacteriaceae and Pseudomonas aeruginosa.

Yes, gentamicin has some activity against aerobic Gram-positive bacteria.

An oxygen-dependent transport mechanism.

Because penetration into the cell requires an oxygen-dependent transport.

No, they have no anaerobic or atypical coverage.

Nephrotoxicity and ototoxicity.

One daily dose to decrease side effects.

Concentration dependent killing.

They have a post-antibiotic effect that lasts for a period after the drug is cleared from the body.

Bacteriostatic bacteria.

The 30S subunit.

They inhibit protein synthesis by reversibly binding to the 30S subunit of the ribosome at the A-site, preventing binding of new tRNA molecules loaded with amino acids.

Tetracycline, Doxycycline, Minocycline.

Broad spectrum including Gram positive bacteria, Gram negative bacteria, anaerobic bacteria, and atypical bacteria.

They can cause gray to yellow discoloration of actively forming teeth.

Pregnant and lactating women, and children under 8 years old.

Photosensitivity.

Hepatic and renal toxicity, and gastrointestinal distress.

Tetracyclines

Broad antimicrobial spectrum

Aerobic gram-positive bacteria including MRSA and VRE, aerobic gram-negative bacteria, anaerobic bacteria, and atypical bacteria.

Pseudomonas spp.

Doxycycline and Tigecycline.

Doxycycline.

Tetracycline, Doxycycline, and Minocycline.

It binds to the 50S subunit of the ribosome, inhibiting the bacterial enzyme peptidyl transferase, which prevents the growth of the polypeptide chain during protein synthesis.

Bacteriostatic.

Broad spectrum of activity, effective against anaerobic and atypical bacteria.

Bone marrow suppression leading to fatal aplastic anemia.

Gray baby syndrome.

Superficial eye infections, bacterial meningitis, typhoid fever, and cholera.

Erythromycin, Clarithromycin, Azithromycin, Telithromycin.

At the P-site of the 50S ribosomal subunit.

They inhibit the transfer of the peptidyl tRNA from the A site to the P site.

Bacteriostatic.

Erythromycin, Clarithromycin, Azithromycin, Telithromycin.

Some Gram-positive bacteria, some Gram-negative bacteria, some atypical bacteria, some mycobacteria, and some spirochetes.

Treatment of respiratory tract infections, gonorrhea, and typhoid.

Gastric disturbances, cholestatic jaundice, and ototoxicity at high doses.

Erythromycin

Clarithromycin has greater activity against aerobic Gram-positive bacteria and H. influenzae than erythromycin.

Azithromycin is taken up in high amounts by tissues and then slowly released over subsequent days.

For 10 days.

It is less effective compared to Clarithromycin and Azithromycin.

Clindamycin and Lincomycin.

Clindamycin.

Both oral and intravenous forms.

The mechanism of action of macrolides.

Aerobic Gram-positive bacteria and anaerobic bacteria.

No, they are not active against aerobic Gram-negative bacteria.

Pseudomembranous colitis, also called antibiotic-associated colitis.

A mixture of Quinupristin/dalfopristin.

They bind to the 50S subunit of the bacterial ribosome to inhibit protein synthesis.

It inhibits the early stage of protein synthesis.

It inhibits the late stage of protein synthesis.

A bactericidal effect.

Aerobic Gram-positive bacteria including MRSA, penicillin-resistant S. pneumoniae, and VRE.

Pain, inflammation, and thrombophlebitis at the site of infusion.

Through a central venous catheter.

Completely synthetic compounds.

They bind the 50S subunit, preventing its association with the 30S subunit, thus preventing ribosome assembly.

Most aerobic Gram-positive bacteria, including MRSA, VRE, and penicillin-resistant S. pneumoniae.

It inhibits protein synthesis by forming a stable complex with elongation factor EF-G.

It is used topically in creams and eyedrops.

Mainly against Gram-positive bacteria.

Treatment of staphylococcal infections.

Bacteriostatic.

Aminoglycosides, Tetracyclines, Glycylcyclines.

Chloramphenicol, Macrolides, Lincosamides, Streptogramins, Oxazolidinones.

They are a class of antibiotics that interfere with the synthesis of nucleic acids in bacteria.

Quinolones are a type of nucleic acid synthesis inhibitor.

Rifamycins are a class of antibiotics that inhibit nucleic acid synthesis.

Metronidazole is a nucleic acid synthesis inhibitor.

Nitrofurans are used as nucleic acid synthesis inhibitors in treating bacterial infections.

They work by inhibiting two topoisomerases: DNA gyrase (topoisomerase II) for Gram-negative bacteria and Topoisomerase IV for Gram-positive bacteria, leading to inhibition of DNA synthesis and bacterial death.

They have broad activity against various bacteria.

Fluoroquinolones are mostly fluorinated, except for nalidixic acid.

It is active against Gram-negative organisms except Pseudomonas species.

It is used for urinary tract infections.

They are active against Gram-negative (including Pseudomonas species), some Gram+ (S. aureus), and some atypical bacteria.

They are used for urinary tract infections, sexually transmitted diseases, and skin and soft-tissue infections.

Same as 2nd generation with extended Gram+ and atypical coverage.

Respiratory infections, community-acquired pneumonia.

Same as 3rd generation with broad anaerobic coverage.

Same as for first-, second-, and third-generation agents.

Gastrointestinal disturbances such as nausea and diarrhea.

Headache and dizziness.

Tendon rupture.

Cartilage abnormalities.

In children younger than 18 years of age.

Due to potential risks to the fetus.

QT prolongation, increasing the risk of Torsades de Pointes.

A normal heart rhythm with clear P, Q, R, S, and T waves.

A longer QT interval than normal, which may suggest potential cardiac issues.