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Uterine Relaxant Drugs

πŸ‘ΆπŸ» Preterm labor occurs when labor begins too early. If this happens before the 37th week of gestation, the fetal organs, especially the lungs, might not be fully developed.⁠
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πŸ’Š In these cases, labor can be suppressed with uterine relaxants that relax the uterine muscle and slow down contractions for up to 48 hours. It gives the fetus a few more days in the uterus as a corticosteroid is given to speed up the development of a preterm infant’s lungs. Steroids help the lungs mature and may promote the production of surfactant, a substance that prevents the collapse of alveoli (small sacs in the lungs where the air is exchanged). ⁠
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πŸ’Š Uterine relaxants are also called tocolytics (toco = childbirth, lytic = terminate) and include several different types of drugs. ⁠
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Antibiotic Renal Dosing

Antibiotics are commonly used to treat infections. When considering what dose to prescribe to a patient, it is important to evaluate the patient’s renal function as many antibiotics are excreted by the kidney.⁠ ⁠ It is recommended to study the list of antibiotics that do NOT require renal dose adjustments rather than a list of the ones that do (as it can get very long and overwhelming). ⁠

Diuretic Classes

There are 5 main types of diuretic classes with different mechanisms of action, site of action, and side effect profiles. ⁠ ⁠ 1) Loop diuretics work on the loop of Henle (as the name implies)⁠ 2) Osmotic diuretic work on the glomerulus⁠ 3) Thiazides work on distal convoluted tubule⁠ 4) Carbonic anhydrase work on the proximal tubule⁠ 5) Potassium-sparing diuretics (aldosterone antagonists and sodium channel blockers) work on the distal convoluted tubule⁠ and collecting ducts
ketamine mnemonic

Ketamine Properties

πŸ“– Ketamine is a medication primarily used for starting and maintaining anesthesia. It induces dissociative anesthesia, a trance-like state providing pain relief, sedation, and amnesia.⁠
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⭐ The distinguishing features of ketamine anesthesia are preserved breathing and airway reflexes, stimulated heart function with increased blood pressure, and moderate bronchodilator.⁠

Antibiotics that cover anaerobes

Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria are most commonly found in the gastrointestinal tract. ⁠ ⁠ πŸ”Ί They play a role in conditions such as appendicitis, diverticulitis, and perforation of the bowel so it is important to make sure we have adequate anaerobic coverage when empirically treating these infections. ⁠ ⁠ πŸ’Š There are several antibiotics that cover anaerobes in addition to other bacteria. ⁠

Antibiotics that cover Pseudomonas

Pseudomonas is a type of bacteria (bug) that is found commonly in soil and in water. Of the many different types of Pseudomonas, the one that most often causes infections in humans is called Pseudomonas aeruginosa, which can cause infections in the blood, lungs (pneumonia), or other parts of the body after surgery.⁠ ⁠ πŸ”Ί Pseudomonas aeruginosa treatment has become increasingly difficult as bacteria become more resistant to the available antibiotics on the market. If they develop resistance to several types of antibiotics, these germs can become multidrug-resistant.⁠

Antituberculosis Agents

Tuberculosis (TB) is caused by Mycobacterium tuberculosis (aerobic, non-spore forming bacillus). Active TB is transmitted by aerosolized droplets (sneezing, coughing, talking, etc.) and is highly contagious. ⁠ ⁠ Active disease treatment is divided into two treatment phases, initial and continuation. To avoid treatment failure due to resistance, the preferred initial treatment consists of a 4 drug regimen of rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE). ⁠ ⁠ These 4 drugs are taken for about 8 weeks during the initiation phase. In the continuation phase, the regimen is narrowed based on susceptibilities.

Asthma, Management of

πŸ“– Asthma is a common airway disease and has a range of severity, from a very mild, occasional wheeze to acute, life-threatening airway closure. It usually presents in childhood and is associated with other features of atopy, such as eczema and hayfever.⁠
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πŸ’Š Medical management includes bronchodilators like beta-2 agonists and muscarinic antagonists (salbutamol and ipratropium bromide respectively) and anti-inflammatories such as oral or nebulized steroids. Theophylline was once popular but is rarely used due to its narrow therapeutic index and side effect profile. However, it is still important to note as there are patients still treated with it. ⁠
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πŸ’Š Patients with life-threatening asthma are managed with high flow oxygen inhalation, systemic steroids, back-to-back nebulizations with short-acting beta 2 agonists, and short-acting muscarinic antagonists, and intravenous magnesium sulfate.⁠
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πŸ’Š Antibiotics should only be used if an infection is suspected (positive CXR, symptoms of cough and purulent sputum production, fever, high WBC, etc.) and should be withheld if not, to reduce the rise of antimicrobial resistance. ⁠

Beta-1 Cardioselective Beta-Blockers

❀️ Cardioselective beta-blockers work on the beta-1 receptors. Beta-1 receptors primarily are found in cardiac tissues whereas beta-2 receptors are located in the lungs (remember: 1 heart, two lungs). ⁠
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❀️ Cardioselective beta-blockers exert their effect by binding to the beta-1 receptor sites selectively and inhibiting the action of epinephrine and norepinephrine on these sites. They are often preferred in patients with respiratory disease as they are less likely to cause constriction of airways or peripheral vasculature.⁠

Calcium Channel Blockers (Mechanism of Action)

πŸ’Š Calcium channel blockers (CCBs) are used in the treatment of many cardiovascular conditions including hypertension and angina. They are divided into subclasses, non-dihydropyridines, and dihydropyridines and differ by their pharmacokinetic properties, clinical uses, response, and selectivity. ⁠
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πŸ’Š The name of this class, calcium channel blockers, hints at its mechanism of action – inhibits the entry of calcium into cells of the cardiac and peripheral vascular smooth muscles. ⁠
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πŸ—’οΈ Calcium entry into L-type channels of cardiac and peripheral vascular cells is needed for them to contract or constrict more strongly. ⁠
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πŸ—’οΈ By blocking calcium entry, calcium channel blockers cause:⁠
πŸ‘‰πŸ» peripheral vascular smooth muscle relaxation (decreases blood pressure)⁠
πŸ‘‰πŸ» decreased myocardial contractility (decrease myocardial demand making them effective in angina)⁠
πŸ‘‰πŸ» decrease heart rate and conduction velocity (useful in arrhythmias). ⁠

Cholinergic Muscarinic Agonist Effects

πŸ‘‰πŸ» Cholinergic muscarinic agonists are drugs that bind to and activate muscarinic cholinergic receptors and increase the activity of the parasympathetic nervous system. They are most commonly used when it is desirable to increase smooth muscle tone, especially in the GI tract, urinary bladder, and eye. They may also be used to reduce heart rate. ⁠
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πŸ‘‰πŸ» Direct cholinergic agonists work by resisting acetylcholinesterase, thus preventing its breakdown. Drugs in this class include bethanechol, carbachol, and methacholine, and pilocarpine.⁠
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πŸ‘‰πŸ» Indirect cholinergic agonists work by inhibiting the acetylcholinesterase enzyme preventing the degradation of acetylcholine. Drugs in this class include neostigmine, physostigmine, galantamine, donepezil, and rivastigmine. ⁠