Classification of Drugs Use and Action Use: Why we are giving the drug, the indication. Why is the patient receiving this medication. Action: How does the drug work, how does it do its job/function. 1A opioid analgesics General Use Management of moderate to severe pain. Fentanyl is also used as a general anesthetic adjunct. General Action and Information Opioids bind to opiate receptors in the CNS, where they act as agonists of endogenously occurring opioid peptides (eukephalins and endorphins). The result is alteration to the perception of and response to pain. 1B nonopioid analgesics General Use Used to control mild to moderate pain and/or fever. Phenazopyridine is used only to treat urinary tract pain, and capsaicin is used topically for a variety of painful syndromes. General Action and Information Most nonopioid analgesics inhibit prostaglandin synthesis peripherally for analgesic effect and centrally for antipyretic effect. anti-alzheimers agents General Use Management of Alzheimer's dementia. General Action and Information All agents act by ↑ the amount of acetylcholine in the CNS by inhibiting cholinesterase. No agents to date can slow the progression of Alzheimer's dementia. Current agents may temporarily improve cognitive function and therefore improve quality of life. antidiarrheals General Use For the control and symptomatic relief of acute and chronic nonspecific diarrhea. General Action and Information Diphenoxylate/atropine, difenoxin/atropine, and loperamide slow intestinal motility and propulsion. Bismuth subsalicylate affects fluid content of the stool. Bismuth subsalicylate is also used as part of the management of peptic ulcer disease due to Helicobacter pylori. Polycarbophil acts as an antidiarrheal by taking on water within the bowel lumen to create a formed stool. Polycarbophil may also be used to treat constipation. Octreotide is used specifically for diarrhea associated with GI endocrine tumors. anticoagulants General Use Prevention and treatment of thromboembolic disorders including deep vein thrombosis, pulmonary embolism, and atrial fibrillation. Also used in the management of myocardial infarction (MI) sequentially or in combination with thrombolytics and/or antiplatelet agents. General Action and Information Anticoagulants are used to prevent clot extension and formation. They do not dissolve clots. The main types of anticoagulants in common use are parenteral heparins, oral warfarin, oral/parenteral direct thrombin inhibitors, and oral/parenteral factor Xa inhibitors. When initiating warfarin, unfractionated heparin or a low-molecular weight heparin is usually administered concomitantly initially since warfarin takes several days to produce therapeutic anticoagulation. Once a therapeutic anticoagulant effect is achieved with warfarin, the unfractionated heparin or low-molecular weight heparin will be discontinued. Unfractionated heparin (at lower doses), a low-molecular weight heparin (at lower doses), or fondaparinux are mostly used to prevent deep vein thrombosis after certain surgical procedures or situations in which prolonged bedrest increases the risk of thromboembolism. Argatroban is used to provide anticoagulation in patients who have developed thrombocytopenia during heparin therapy. antidiabetics General Use Insulin is used in the management of type 1 diabetes mellitus. It may also be used in type 2 diabetes mellitus when diet and/or oral medications fail to adequately control blood sugar. The choice of insulin preparation (rapid-acting, intermediate-acting, longacting) depends on the degree of control desired, daily blood glucose fluctuations, and history of previous reactions. Oral agents non-insulin injectable agents are used primarily in type 2 diabetes mellitus. Oral agents are used when diet therapy alone fails to control blood glucose or symptoms or when patients are not amenable to using insulin or another injectable agent. Some oral agents may be used with insulin. General Action and Information Insulin, a hormone produced by the pancreas, lowers blood glucose by ↑ transport of glucose into cells and promotes the conversion of glucose to glycogen. It also promotes the conversion of amino acids to proteins in muscle, stimulates triglyceride formation, and inhibits the release of free fatty acids. Sulfonylureas, nateglinide, repaglinide, the dipeptidyl peptidase 4 (DPP-4) inhibitors (e.g. sitagliptin), and the glucagon-like peptide1 (GLP-1) receptor agonists (e.g. exenatide) ↓ blood glucose by stimulating endogenous insulin secretion by beta cells of the pancreas and by ↑ sensitivity to insulin at intracellular receptor sites. Intact pancreatic function is required. Acarbose and miglitol delay digestion of ingested carbohydrates, thus ↓ blood glucose, especially after meals. The thiazolidinediones (e.g. pioglitazone) and metformin ↑ insulin sensitivity. The sodium-glucose transporter 2 (SGLT2) inhibitors (e.g. empagliflozin) inhibit the reabsorption of glucose in the proximal renal tubule, thereby ↑ the excretion of glucose in the urine. antihypertensives General Use Treatment of hypertension of many causes, most commonly essential hypertension. Parenteral products are used in the treatment of hypertensive emergencies. Oral treatment should be initiated as soon as possible and individualized to ensure adherence and compliance for long-term therapy. Therapy is initiated with agents having minimal side effects. When such therapy fails, more potent drugs with different side effects are added in an effort to control BP while causing minimal patient discomfort. General Action and Information As a group, the antihypertensives are used to lower BP to a normal level (<130–140 systolic and <80–90 mm Hg diastolic) or to the lowest level tolerated. The goal of antihypertensive therapy is prevention of end-organ damage. Antihypertensives are classified into groups according to their site of action. These include alpha-1 receptor antagonists, centrally-acting alpha-adrenergic agonists; beta blockers; vasodilators; ACE inhibitors; angiotensin II receptor blockers (ARBs); calcium channel blockers; renin inhibitors; and diuretics. Hypertensive emergencies may be managed with parenteral agents, such as nitroprusside, nicardipine, or beta blockers (e.g. esmolol, labetalol). anti-infectives General Use Treatment and prophylaxis of various bacterial infections. See specific drugs for spectrum and indications. Some infections may require additional surgical intervention and supportive therapy. General Action and Information Kill (bactericidal) or inhibit the growth of (bacteriostatic) susceptible pathogenic bacteria. Not active against viruses or fungi. Anti-infectives are subdivided into categories depending on chemical similarities and antimicrobial spectrum. antipsychotics General Use Treatment of acute and chronic psychoses, particularly when accompanied by ↑ psychomotor activity. Use of clozapine is limited to schizophrenia unresponsive to conventional therapy. Selected agents are also used as antihistamines or antiemetics. Chlorpromazine is also used in the treatment of intractable hiccups. General Action and Information Block dopamine receptors in the brain; also alter dopamine release and turnover. Peripheral effects include anticholinergic properties and alpha-adrenergic blockade. Typical antipsychotics include the phenothiazines and haloperidol. Atypical antipsychotics may have fewer adverse reactions compared to the typical antipsychotics and include aripiprazole, asenapine, brexpiprazole, cariprazine, clozapine, iloperidone, lurasidone, paliperidone, olanzapine, paliperidone, pimavanserin, quetiapine, risperidone, and ziprasidone. Phenothiazines differ in their ability to produce sedation (greatest with chlorpromazine and thioridazine), extrapyramidal reactions (greatest with prochlorperazine and trifluoperazine), and anticholinergic effects (greatest with chlorpromazine). anti-ulcer agents General Use Treatment and prophylaxis of peptic ulcer and gastric hypersecretory conditions such as Zollinger-Ellison syndrome. Histamine H2-receptor antagonists (blockers) and proton pump inhibitors are also used in the management of gastroesophageal reflux disease (GERD). General Action and Information Because a great majority of peptic ulcer disease may be traced to GI infection with the organism Helicobacter pylori, eradication of the organism ↓ symptomatology and recurrence. Anti-infectives with significant activity against the organism include amoxicillin, clarithromycin, metronidazole, and tetracycline. Bismuth also has antiinfective activity against H. pylori. H. pylori treatment regimens usually include: a proton pump inhibitor, and 2 anti-infectives with or without bismuth subsalicylate for 10–14 days. Other medications used in the management of gastric/duodenal ulcer disease are aimed at neutralizing gastric acid (antacids), ↓ acid secretion (histamine H2 antagonists, proton pump inhibitors, misoprostol), or protecting the ulcer surface from further damage (misoprostol, sucralfate). Histamine H2-receptor antagonists competitively inhibit the action of histamine at the H2 receptor, located primarily in gastric parietal cells, resulting in inhibition of gastric acid secretion. Misoprostol ↓ gastric acid secretion and ↑ production of protective mucus. Proton pump inhibitors prevent the transport of hydrogen ions into the gastric lumen. diuretics General Use Thiazide diuretics and loop diuretics are used alone or in combination in the treatment of hypertension or edema due to HF or other causes. Potassium-sparing diuretics have weak diuretic and antihypertensive properties and are used mainly to conserve potassium in patients receiving thiazide or loop diuretics. Osmotic diuretics are often used in the management of cerebral edema. General Action and Information Enhance the selective excretion of various electrolytes and water by affecting renal mechanisms for tubular secretion and reabsorption. Groups commonly used are thiazide diuretics and thiazide-like diuretics (chlorothiazide, chlorthalidone, hydrochlorothiazide, indapamide, and metolazone), loop diuretics (bumetanide, furosemide, and torsemide), potassium-sparing diuretics (amiloride, spironolactone, and triamterene), and osmotic diuretics (mannitol). Mechanisms vary, depending on agent. lipid lowering agents General Use Used as a part of a total plan including diet and exercise to ↓ blood lipids in an effort to ↓ the morbidity and mortality of atherosclerotic cardiovascular disease and its sequelae. General Action and Information HMG-CoA reductase inhibitors (atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, simvastatin) inhibit an enzyme involved in cholesterol synthesis. The PCSK9 inhibitors (alirocumab, evolocumab) facilitate clearing of LDL from the blood. Bile acid sequestrants (cholestyramine, colestipol, colesevelam) bind cholesterol in the GI tract. Ezetimibe inhibits the absorption of cholesterol in the small intestine. Fenofibrate, gemfibrozil, and niacin act by other mechanisms (see individual monographs). nonsteroidal anti inflammatory agents NSAIDs General Use NSAIDs are used to control mild to moderate pain, fever, and various inflammatory conditions, such as rheumatoid arthritis and osteoarthritis. Ophthalmic NSAIDs are used to ↓ postoperative ocular inflammation, to inhibit perioperative miosis, and to ↓ inflammation due to allergies. General Action and Information NSAIDs have analgesic, antipyretic, and anti-inflammatory properties. Analgesic and anti-inflammatory effects are due to inhibition of prostaglandin synthesis. Antipyretic action is due to vasodilation and inhibition of prostaglandin synthesis in the CNS. COX2 inhibitors (celecoxib) may cause less GI bleeding. thrombolytics General Use Acute management of ST-segment-elevation MI. Alteplase is also used in the management of acute pulmonary embolism and acute ischemic stroke. General Action and Information Converts plasminogen to plasmin, which then degrades fibrin in clots. Alteplase, reteplase, and tenecteplase directly activate plasminogen. Results in lysis of blood clots.
