00:00 Let's move on to the tetracyclines. 00:03 Now tetracyclines are very commonly used. 00:05 They are broad spectrum bacteriostatic medications that are used mostly orally. 00:10 They work both through gram positive and gram negative bacteria. 00:15 And they may actually work with some protozoan as well. 00:19 There's widespread resistance with two big major mechanisms. 00:24 The first one is through a development of an efflux pump. 00:27 And that's often seen in the porteus and the pseudomonas species. 00:33 And in fact porteus and pseudomonas are quite interesting because they have multidrug pumps. 00:38 So they actually have these pumps that will eject the whole host of different medications. 00:42 And the second mechanism of resistance is through ribosomal protection proteins that actually prevent binding. 00:48 Almost like a little shield around the ribosome. 00:51 The prototypical drug in the tetracycline family is actually doxycycline or tetracycline. 00:59 Doxycycline is used long term in acne treatment. 01:03 It has a very long duration of activity. 01:07 And it's relatively non-toxic. 01:09 It's also used in bronchitis, bronchitis prevention and leptospirosis. 01:14 Minocycline is used almost exclusively in acne. 01:18 Demeclocycline is useful in most infectious diseases. 01:22 And also has a bit of a diuretic effect. 01:25 So if you go back to hormonal lectures and the adrenal lectures that we've spoken about, you will see that we have talked about demeclocycline and antidiuretic hormones secreting tumors. 01:37 In terms of the toxicity of tetracyclines. 01:40 First of all GI symptoms and I think all tetracyclines are suspect with this. 01:46 They have common but minor side effects, there is very rare episodes of life-threatening enterocolitis, but, it's certainly there. 01:54 It does eliminate normal gut flora, so, you can be prone to bacterial overgrowth syndrome and candidiasis. 02:03 Now, fetal exposure to this medication, results in dental enamel dysplasia. 02:08 This is a common exam question, i do want you to remember this. 02:12 So tetracyclines with fetal exposure, dental enamel dysplasia. 02:19 In terms of other side effects, you can get hepatotoxicity, like most antibiotics, dizziness, vertigo and that's mostly with doxycycline.
The lecture Tetracyclines – Bacterial Protein Synthesis Inhibitors (Antibiotics) by Pravin Shukle, MD is from the course Antimicrobial Pharmacology.
Which statement about tetracyclines is INCORRECT?
What is a common indication for doxycycline?
What is NOT a common adverse effect of tetracyclines?
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