Pharmacology Study Notes: Key Drug Classes and Mechanisms

Pharmacology Study Notes

Cholinergic Receptors and Autonomic Nervous System

• Two receptor types for acetylcholine: muscarinic and nicotinic
• Sympathetic (SNA) location: thoracolumbar
• Parasympathetic location: craniosacral
• Vagus nerve effect: decreases heart rate, delays conduction of the pulse
• Cholinergic agonists: acetylcholine, pilocarpine, carbachol
• Cholinergic agonist uses: bladder atony, glaucoma, Sjögren syndrome
• Anticholinergic example: ipratropium bromide

Bronchodilators and Beta-2 Agonists

• Short-acting: albuterol, pirbuterol, terbutaline
• Long-acting: formoterol, salmeterol xinafoate
• Salbutamol belongs to the B2 adrenergic agonist family
• Metaproterenol is also used in asthma treatment
• Beta-2 adrenergic antagonist examples: metaproterenol, albuterol, terbutaline (note: these are agonists)

Beta Blockers and H2 Blockers

• Beta blockers act by blocking beta receptors, decreasing renin release and reducing angiotensin II
• H2 blockers: ranitidine, famotidine, nizatidine, cimetidine
• Proton pump inhibitors: omeprazole, rabeprazole, pantoprazole

Antihypertensive Drugs

• ACE inhibitors: captopril, lisinopril, enalapril, benazepril, ramipril, perindopril
• Initial dose of captopril: 25 mg
• ARBs (angiotensin II receptor blockers): losartan, valsartan, candesartan
• Calcium channel blockers: nifedipine, dihydropyridines, phenylalkylamines, benzothiazepines
• Calcium channel antagonist effects: excessive vasodilation, drowsiness, rash
• Calcium channel agonist effects: reduced peripheral resistance, reduced myocardial contraction, decreased blood pressure
• Methyldopa: antihypertensive agent
• Urgent hypertension treatment: nitroglycerin, nicardipine, nitroprusside

Diuretics

• Types: thiazide, loop of Henle, osmotic, carbonic anhydrase inhibitors
• Thiazides (benzothiadiazides) inhibit NaCl transport in the distal collecting tubules
• Furosemide acts on the loop of Henle

Lipid-Lowering Agents

• Statins: linked to rhabdomyolysis
• Fibrates: decreased sexual desire, abdominal pain, tenderness
• Normal blood cholesterol: less than 200 mg/dL
• Hyperlipidemia: increased triglycerides
• Hypercholesterolemia: increased cholesterol
• Mixed hyperlipidemia: both triglycerides and cholesterol increased

Cardiac and Other Drugs

• Digoxin: increases contraction frequency and vagal tone
• Digitalis: used in heart failure, tachycardia, and arrhythmias
• Warfarin: anticoagulant
• Histamine: smooth muscle relaxant (used in premature birth)
• Myasthenia gravis treatment: pyridostigmine, neostigmine
• Opiate intoxication signs: coma, respiratory depression
• Pancuronium: inhibits nerve impulse transmission at the neuromuscular junction

Anesthesia

• Barbiturate used in preoperative anesthesia: thiopental
• General anesthetics: propofol, etomidate, ketamine
• Local anesthetic classes: ester (cocaine, benzocaine, procaine) and amide (lidocaine, prilocaine, bupivacaine, ropivacaine)

Other Key Information

• Renin-angiotensin system: occurs in juxtaglomerular cells
• Hypotonic sodium chloride solution concentration: 0.45%
• Hartmann solution: sodium chloride, potassium chloride, calcium chloride, sodium lactate
• Benzodiazepine effects: hypnotic, sedative, and anxiolytic
• Flurosemide site of action: ascending limb of the loop of Henle
• Delivery devices: mask, endotracheal cannula, reservoir, vent