Drug Classifications

1. Drug Classifications • Drugs are a diverse and fall into many categories • The most common categories of medications will be covered here • There are others but in the interest of importance and simplicity the following lecture should provide a general starting point

2. Analgesics • Drug used to suppress pain. Drugs can work via different mechanisms to suppress pain. • Opiate Analgesics stop pain by opiate receptor activation in the brain and spinal cord interrupting the pain signal • Nonopiate Analgesics work by different mechanisms include drugs called nonsteroidal anti inflammatory drugs (NSAIDs) • For example see table 20-1, pg 373 in the The Pharmacy Technician Foundations and Practices text

3. Anti-Infectives • Agents that are used to treat microrganism infection in the body • The class include: • Antibiotics : Penicillins and cephalosporins • Antivirals: Acyclovir, ganciclovir, • Antituberculosis-isoniazid, ethambutol, pyrazinamide • Antiretrovals: NRTI: Zidovudine, NNRTI-efavirenz, PI-ritonavir • Fluoroquinolones: ciprofloxacin, levofloxacin • Antimalarial: (treat miliaria): quinine sulfate • Antifungals: Fluconazole (Diflucan®), amphotericin (Amphocin®) • Please see table 20-2 in the textbook for a complete list

4. Antibiotic mechanism of action • Penicillin and Cephalosporins: drugs inhibit the formation of the bacterial cell wall. Bacteria swell and die. Drugs are bactericidal • Macrolides: inhibits bacterial ribosomes and protein synthesis. Example includes erythromycin (E-Mycin®) and azithromycin (Zithromax®). Bactericidal or Bacteriostatic. • Tetracyclines: Bacteriostatic by inhibiting protein sysnthesis. • Fluroquinolones: Bactericidal. Binds to DNA • Aminoglycosides: (Gentamicin) Bactericidal by several mechanisms

5. Antineoplastics • Cancer chemotherapy agents • Alkylating agents: chemical modify RNA so it is no longer able to be translated. Example: cyclophosphamide. Cyclophosphamide is sometimes used to treat autoimmune disorder as well (Lupus nephritis) • Antimetabolites: agent that acts as chemical decoy to block the cell from dividing. Example: methothexate which is a folic antagonist. Sometimes seen as MTX and is used to treat some autoimmune disorders as well as RA • Antineoplastic antibiotics: inhibits RNA and DNA synthesis. Example is epirubicin (Ellence®) • Anti hormones: inhibits the growth of cancer cells that are hormone sensitive. Example is Tamoxifen which is used to treat breast cancer post surgery • See page 377 table 20-3 for a complete list

6. Cardiovascular Drugs • Beta Blockers: drugs that block the beta receptors in the heart which blocks attachment of norepinephrine and results in bradycardia and reduced blood pressure. Examples are propranolol(Inderal®), metoprolol (Toprol XL, lopressor ®), atenolol (tenormin®) This is an important drug used in heart failure patients, patient that have had an MI, and hypertensive patients. • ACE inhibitors (angiotensin converting enzyme inhibitor) blocks the enzyme (ACE) responsible to converting angiotensin I to angiotensin II (ATII). ATII is a potent vasoconstrictor in humans. ATII is also important in kidney function. ATII also increases aldosterone secretion. This drug is important in hypertensive patients and patients with CHF and MI. ACEI are also important in preservation of kidney function in diabetics.Examples are enalapril( Vasotec®) and Ramipril (Altace®)

7. Antianginal agents: used to widen coronary arteries to increase myocardial oxygen delivery and reduce chest pain. Examples: nitroglycerin (NTG), and isosorbide (Imdur®, Isordil®) • Calcium channel blockers: blocks the entry of calcium ions in the heart muscle and in the muscle that control blood vessel diameter. Reduced heart rate and reduces blood pressure. Some are used to control a type of cardiac arrhythmia called atrial fibrillation. Examples: Diltiazem (Tiazac®, Cardizem®), amlodipine (Norvasc®) • Antiarrhythmial agents: block the entry of sodium into the heart. The drugs in this class have several mechanisms of action. Examples: Lidocaine, amiodarone (Cordarone®), Procainamide (Procanbid®)

8. Angiotensin 2 Receptor blockers (ARB’s): similar to ACEI except these drug works on a receptor for ATII. Examples are Losartan (Cozaar®), valsartan (Diovan®) • Anticoagulation agents: drugs that block the formation of blood clots. Different mechanisms of action. Examples: warfarin (coumadin®), dibigatran (Pradaxa®) • Antiplatelet agents: drugs that block the action of platelets in the formation of a blood clot. Used in the prevention of stroke or MI. Examples: Clopidegrel (Plavix®) and Aspirin (Ecotrin®)

9. Antihyperlipidemics: drugs used to treat high blood lipid levels (cholesterol, triglycerides) Examples are the statin drugs, Niacin (Niaspan®), Omega 3 fatty acid (Lovaza®) • Cardiac glycosides: drugs used to boost the strenght of the heart’s contraction. Example: Digoxin (Lanoxin®)

10. Diuretics • Drugs that work at the kidney to help remove sodium, water, calcium, and potassium from the body. Each class of diuretic is named for the most part according to its mechanism of action or the site of action in the kidney. • Loop Diuretics work in a section of the kidney called the loop of henle. This is where most of the water and sodium and potassium is lost from the body. These drugs are used to treat edema in CHF patients and other patient that hold on the water. • Example(s): Furosemide (Lasix®), Torsemide (Demadex®)

11. Carbonic anhydrase inhibitors act on the proximal tubule of the kidney by blocking the enzyme, carbonic anhydrase which cause sodium retention and acid loss. • Example: acetazolamide (Diamox®) • Carbonic anhydrase inhibitor are pretty much weak diuretics and can produce profound lose of potassium

12. Thiazide Diuretics • Thiazide diuretics act on the distal convoluted tubule to block the NaCLcotransporter in the kidney. • Generally good diuretics • Produce a sodium rich urine • Example: Hydrochlorothiazide (HydroDiuril®)

13. Potassium Sparing diuretics • Most of the above diuretics cause profound lose of potassium. To circumvent this, these diuretic are usually taken with potassium supplements. • A class of diuretic that “spares” potassium in the body are know and are used for many indications • Examples are: spironolactone (aldactone®), Amiloride (Midamor®), and the ACE inhibitors with ARB’s. • These diuretics unlike the ones mentioned before should not be used with a potassium supplement.

14. Central Nervous System Drugs • Sedatives and Tranquiller: Drugs that cause depression of the reticular activating system in the brain. Differences in mechanisms of action. • Examples are • barbiturates: Phenobarbital (Luminal®) • Benziodiazepines: Chlordiazepoxide (Librium®), Diazepam (Valium®), Lorazepam (Ativan®), Alprazolam (Xanax®) • BDZ were developed in the 1960’s with the advent of librium®. BDZ are safer than barbiturates. Both dangerous with alcohol consumption. • Used in anxiety disorder, panic disorder, GAD, sleep disorders • Control Substance: CIV • Miscellanous agents in the class are zolpidem (Ambien®), zaleplon (Sonata®)

15. Neuroleptic agents: drug used in the treatment of schizophrenia and other personality disorders. Examples include: • Dopamine block agents: Haloperidol (Haldol®), Chlorpromazine (Thorazine®), Fluphenazine (Prolixin®) • Dopamine and serotonin blocking agents: Olanzapine (Zyprexa®) and Quetiapine (Seroquel®)

16. Drugs used to treat ADHD in children and adults • Mixed amphetamine salts: Adderall® XR • Other agents: Methylphenidate (Ritalin® Concerta ®, Focalin ®)

17. Antiepileptics • Drugs used to treat seizures. Many of the drugs block the sodium ion channel in nerves. • Examples include: • Phenytoin (Dilantin®) • Valproic acid (Depakene®), Divalproex (Depakote®) • Carbamazepine (Tegretol®) • Drugs in this group are known to cause birth defects and are in category D

18. Drugs used to treat depression • Drugs that block the reuptake of dopamine, serotonin and norepinephrine in the brain are called Tricyclic antidepressants. Drugs in this class include : amitriptyline, nortriptyline. These drugs have fallen into disuse over the decades due to their toxicity in overdose. As little as 1,000 mg of nortriptyline has resulted in fatal overdoses • SSRI or selective serotonin reuptake inhibitors are now most commonly used. Examples include: Fluoxetine (Prozac®), Paroxetine (Paxil®) • SSRIs have been used for other indications

19. Drugs used to treat Diabetes • Insulin: the nature human hormone needed to clear blood glucose. Examples: Ultrafast: Novolog®, Humalog®, Regular insulin (Humulin®), Basal insulin: Lantus® • Sulfonylureas: drugs that increase the release of insulin in the body. Examples include: Glipizide (Glucotrol®), Glyburide. Sulfonylurea should be taken with food • Meglitinides: drugs similar to sulfonylurea by faster acting. Examples: Repaglinide (Prandin®, Nateglinide (Starlix®) • Thiazolidinediones: drugs that increase the body sensitivity to insulin. Example includes: pioglitazone (actos®) • Other agents include: exenatide (Byetta®), sitagliptin (Januvia®) and metformin (Glucophage®)