Inhibidores de la sintesis de proteinas: Macrolidos y Tetraciclinas

Summary

In this educational lecture, Dr. Federico José Turné introduces inhibitors of protein synthesis, focusing on macrolides and tetracyclines. He discusses their mechanism of action, pharmacokinetics, adverse effects, and therapeutic uses. Macrolides, including erythromycin, clarithromycin, and azithromycin, are bacteriostatic and inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit. Tetracyclines, such as tetracycline, doxycycline, and tigecycline, bind to the 30S subunit, preventing aminoacyl-tRNA attachment. The lecture highlights their broad-spectrum coverage, including intracellular bacteria, and touches on resistance patterns and prudent antibiotic use.

Takeaways

• 😀 The class focuses on protein synthesis inhibitors, specifically macrolides and tetracyclines, which are antibiotics used to treat bacterial infections.
• 🔬 Macrolides, including erythromycin, clarithromycin, and azithromycin, inhibit bacterial protein synthesis by reversibly binding to the 50S ribosomal subunit, thus preventing peptide chain translocation.
• 🌡 Macrolides have a broad spectrum of activity, covering both gram-positive and gram-negative bacteria, as well as intracellular pathogens like Chlamydia and Mycoplasma.
• 💊 Erythromycin, the first macrolide discovered, is used for its motilin receptor stimulation, which can increase gastrointestinal motility and is sometimes used off-label for conditions like gastroparesis.
• 🚫 Macrolides are classified as pregnancy category C drugs, meaning their use in pregnant women should be carefully evaluated due to potential risks and benefits.
• 🌟 Azithromycin stands out for its extended half-life of 40 to 68 hours, allowing for once-daily dosing or even single-dose treatments for certain infections.
• 📚 Tetracyclines, including doxycycline and tigecycline, inhibit protein synthesis by binding to the 30S ribosomal subunit, blocking aminoacyl-tRNA access.
• 🛡 Tetracyclines are broad-spectrum antibiotics effective against a wide range of bacteria, including those causing respiratory tract infections, Lyme disease, and certain sexually transmitted infections.
• ⚠️ Certain tetracyclines can cause dental staining in children under 8 years old due to their chelation with calcium, leading to the formation of yellow-grayish teeth.
• 💥 Both macrolides and tetracyclines can have gastrointestinal side effects, and some, like azithromycin, can cause QT interval prolongation, increasing the risk of arrhythmias.

Q & A

What is the main focus of the class taught by Dr. Federico José Turné?

The class focuses on protein synthesis inhibitors, specifically macrolides and tetracyclines, covering their generalities, mechanism of action, pharmacokinetics, adverse effects, interactions, and therapeutic uses.

How do protein synthesis inhibitors work?

Protein synthesis inhibitors work by binding to different sites on the bacterial ribosome, which inhibits protein synthesis, thus stopping bacterial growth.

What are the two main groups of protein synthesis inhibitors discussed in the class?

The two main groups of protein synthesis inhibitors discussed are macrolides and tetracyclines.

What are some examples of macrolides mentioned in the script?

Some examples of macrolides mentioned include erythromycin, clarithromycin, and azithromycin.

What is the primary mechanism of action for macrolides?

Macrolides primarily inhibit protein synthesis by reversibly binding to the 50S ribosomal subunit, preventing peptide chain translocation.

How do tetracyclines differ in their mechanism of action from macrolides?

Tetracylines inhibit protein synthesis by binding to the 30S ribosomal subunit, preventing the attachment of aminoacyl-tRNA to the acceptor site, rather than inhibiting peptide chain translocation like macrolides.

What are the broad-spectrum properties of macrolides and tetracyclines?

Both macrolides and tetracyclines are broad-spectrum antibiotics, covering gram-positive and gram-negative bacteria, as well as intracellular bacteria.

What are some therapeutic uses of macrolides mentioned in the class?

Some therapeutic uses of macrolides include treating respiratory infections, pertussis, and as an alternative to penicillin in penicillin-allergic patients.

What are the potential adverse effects of macrolides?

Potential adverse effects of macrolides include gastrointestinal issues like nausea, vomiting, and diarrhea, as well as potential hearing problems and prolongation of the QT interval leading to arrhythmias.

Why are tetracyclines not recommended for children under a certain age?

Tetracylines are not recommended for children under 8 years old due to the risk of dental staining and potential effects on bone growth.

What are the pharmacokinetic differences between erythromycin and newer macrolides like clarithromycin and azithromycin?

Erythromycin has a shorter half-life and is affected by stomach acidity, requiring enteric coating, while clarithromycin and azithromycin have improved pharmacokinetics with better bioavailability and longer half-lives.