Prescription Drugs

Prescription Drugs

Therapeutic Index Lethal Dose TI= Effective Dose LD – The dose that kills 50% of a population ED – The dose that evokes the desired effect in 50% of a population

Drug Metabolism • P450 System: A group of enzymes found predominantly in the liver that is responsible for the metabolism of drugs • Drugs can be metabolized into: • An active form • An unchanged form • An inactive form

Anti - Anginal • Vasodilators • Decrease workload of the heart • E.g. • Nitrates (Nitroglycerin) • Isordil • Ca++ Channel blockers

Anti-Arrhythmics • Class 1 • Na+ channel blockers (Lidocaine, Quinidine) • Class 2 • Beta Blockers (“olol” drugs) • Class 3 • K+ channel blockers (Amiodarone, Sotalol)

Anti-Arrhythmics • Class 4 • Ca++ channel blockers • Digitalis • Cardiac Glycosides • Adenosine

Na+ Channel Blockers(Class 1) • Sodium (Na+) – effects excitability of the cell and triggers it to fire. Cell is slower to fire without sodium. 1A - Used for SVT, V-tach, V-fib E.g. Quinidine, Procainamide and Disopyramide 1B – Used for V-tach and preventing V-fib E.g. Lidocaine

1C - Used for V-tach, V-fib, refractory SVT • E.g.Propafenone

Beta Blockers • Blocks action of epinephrine and norepinephrine • Decreases HR, Contractility and Conductivity Works on Beta Receptors for tachycardias, MI and HTN • Selective – Blocks B1 receptors (heart) • Used for asthmatics and diabetics • Non-Selective – Blocks B1 and B2 (heart and lungs)

Beta Blockers • Selective – B1 only • Atenolol – Tenormin • Betaxolol – Kerlone • Careteolol – Cartol • Penbutolol – Levatol • Metoprolol – Betaloc, Lopressor • Acebutolol – Secral • Esmolol - Breviblock • Non-Selective • Nadolol – Corguard, Sotolol • Oxprendolol – Trasicor • Pindolol – Visken • Propanol – Inderal • Timolol - Blocarden

Calcium Channel Blockers • Calcium(Ca++) – effects contractility of the heart (how hard it squeezes) • Decreases force of Contraction • Vasodilation • (result of less Ca++ in smooth muscle cells) • Used for treatment of a-fib and a-flutter, ischemic heart disease and angina

Ca+ Channel Blockers • NAVIDC • N – Nifedipine • A – Adalat • V – Verapimil • I – Isoptin • D – Diltiazem • C – Cardizem

Cardiac Glycosides • Digoxin (Lanoxin) • Increases force of contraction (by causing less Ca++ to be released from the cell) “Improved myocardial efficiency” - makes it pump more like a normal heart • Used to control ventricular response rate in a-fib, • a-flutter and used to treat heart failure Narrow therapeutic index

Anti – Hypertensive Drugs • Thiazide Diuretics • Lower BP by increasing sodium and water excretion • Decrease in cardiac output • E.g. HCTZ • Loop Diuretics Inhibiting the kidney's ability to reabsorb sodium, thus enhancing the loss of sodium in the urine, water goes with it. E.g. Lasix

Anti-Hypertensives Beta Blockers Decreases cardiac output E.g. Propranolol, Metoprolol, Atenolol ACE Inhibitors Blocks ACE (angiotensin converting enzyme) Body cannot use its responses to raise the BP E.g. Enalapril, Lisinopril, Altace, Vasotec Angiotensin II Receptor Antagonists Produces vasodilatation Blocks Aldosterone (released to raise BP) E.g. Losartan

Anti-Hypertensives Alpha-Adrenoreceptor-Blocking Agents Decreases peripheral vasculature resistance Relaxation of arterial and venous smooth muscle E.g. Terazosin, Doxazosin Centrally Acting Adrenergic Drugs Clonidine – Stimulates the CNS to decrease its response causing vasodilatation A-methyldopa – Diminishes CNS response and reduces peripheral resistance Vasodilators Relaxation of vascular smooth muscle E.g. Hydralazine, Minoxidil

Benzodiazepines Hyperpolarizes the cell which lowers its excitability (seizure threshold) • E.g. Diazepam, Lorazepam, Oxazepam, Clonazepam

NSAIDS • Nonsteroidal Anti-inflammatory Drugs • Anti-inflammatory • Anti-pyretic • Analgesic • ASA, Ibuprofen, Celecoxid, Diclofenac, Ketorolac

Anti-Depressants Tricyclics • Block reuptake of Serotonin and Norepinephrine in the neuron • E.g. Amitriptyline, Doxepin • Monoamine Oxidase Inhibitors (MAOI) • Blocks MAO (inactivates), allowing neurotransmitters to accumulate activating norepinephrine and serotonin receptors • E.g. Phenelzine • Serotonin Reuptake inhibitors (SSRI) • Slows reuptake of serotonin in the brain • E.g. Fluoxetine, Citalopram

Insulin • Hormone that is central to regulating fat and steroid metabolism in the body • Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle. • Type 1 diabetics – insulin is no longer produced Rapid – short acting (Regular, Toronto) • Intermediate – Lente, NPH, Semilente • Prolonged – Dissolves slowly, long lasting • Sliding Scale – Blood Sugar monitored, insulin adjusted.

Oral Diabetic Medication • Patients with Type 2 diabetes mellitus are insulin resistant • Glyburide– (Sulfonylureas) • Stimulates release of insulin from beta cells of pancreas • Reduces serum glucagon levels • Increases binding of insulin to tissues and receptors • Metformin – (Biguanide) • Improves target cell response to insulin (uptake and use) without increasing pancreatic insulin secretion • Risk of hypoglycemia is less

Bronchodilators • Relaxes muscles surrounding the bronchioles • Blocks Histamine release that stimulates bronchoconstriction • Ventolin, Serevent, Advair, Combivent

Prescription Drugs