Pharmacology

Pharmacology Antacids: decrease gastric acidity, protect stomach mucosa, decrease epigastric pain MOA: binds with excess acid E.g.: magnesium/aluminum hydroxide (Maalox), aluminum hydroxide Antidiarrheals: decreases diarrhea, increases production of formed stool MOA: decreases motility, causing more water E.g.: diphenoxylate HCl (Lomotil), to be absorbed by large intestine loperamide (Imodium) SE: aluminum causes constipation, magnesium causes diarrhea Nursing: avoid foods that increase GI distress, be cautious with overuse (can cause rebound hyperacidity) SE: tachycardia, resp depression, ileus, urinary retention, dry mouth Nursing: monitor for fluid + electrolyte imbalance Antibiotics: destroy or decrease growth of susceptible microorganisms MOA: E.g.: SE: hypersensitivity reactions Aminoglycosides – decrease protein synthesis Gentamicin (rash, anaphylaxis) Cephalosporins – bind to cell wall causing cell Cefazolin (Ancef) death Fluoroquinolones – decrease DNA synthesis Ciprofloxacin (Cipro) Macrolides – decrease protein synthesis Azithromycin (Zithromax) Penicillin – bind to cell wall causing cell death Amoxicillin (Amoxil) Sulfonamides – decrease protein synthesis Doxycycline (Vibramycin) Anti-infectives – decrease protein + DNA Metronidazole (Flagyl) synthesis, bactericidal, trichomonacidal, amebicidal Anticoagulants: interfere with normal coagulation leading to decrease in thrombus formation/extension MOA: E.g.: SE: excessive bleeding Thrombin inhibitors – decreases conversion of Heparin (bruising, melena, epistaxis, prothrombin to thrombin + conversion of bleeding gums, low hgb, fibrinogen to fibrin thrombocytopenia) Low molecular weight heparin – block Dalteparin (Fragmin), enoxaparin coagulation factor Xa (Lovenox) Clotting factor inhibitor – interfere with Vit K Warfarin (Coumadin) synthesis Platelet inhibitors – decrease platelet Clopidogrel (Plavix) aggregation Antiemetics: decrease nausea + vomiting, prevent and decrease motion sickness MOA: E.g.: SE: headache, dizziness, 5 HT3 antagonist – blocks serotonin @ Ondansetron (Zofran) constipation, diarrhea receptor site in vagal nerve terminals + chemoreceptor trigger zone in CNS Antifungals: decrease fungal growth Nursing: C&S should be done before starting med, assess for hepatotoxicity + nephrotoxicity, teach pt that entire prescription is to be completed Nursing: notify MD of bleeding, monitor PTT/PT/INR Nursing: give 30-60 mins before chemo, avoid alcohol 50 MOA: impair fungal plasma membrane SE: renal + liver + ototoxicity, teratogenic, nausea, vomiting, diarrhea Analgesics, Antipyretics, NSAIDS: decrease synthesis of prostaglandins, which decreases pain/fever/inflammation MOA: E.g.: SE: hepatic toxicity, rash, Analgesics – inhibit prostaglandins involved in Acetaminophen (Tylenol) tinnitus, flu-like S/S pain + fever NSAID – inhibit prostaglandins involved in Ibuprofen (Advil, Motrin), naproxen inflammation, pain, and fever (Aleve, Naprosyn) Antihistamines: decreases S/S of allergy + motion sickness MOA: blocks histamine, which decreases E.g.: diphenhydramine (Benadryl), SE: dry eyes + mouth, allergic responses and motion sickness loratadine (Claritin) constipation, blurred vision, sedation Antihypertensives: decreases BP MOA: ACEI – decreases release of aldosterone which increases the excretion of Na and H20 CCB – increases relaxation and dilation of vascular smooth muscle of coronary arteries ARB – decreases vasoconstriction and decreases release of aldosterone BB (selective) – blocks stimulation of beta 1 (myocardial) receptors BB (nonselective) – blocks stimulation of beta1 (myocardial) and beta2 (pulmonary) receptors E.g.: clotrimazole (Mycelex), nystatin (Mycostatin) E.g.: SE: dizziness, weakness, Enalapril (Vasotec), lisinopril (Prinivil), flushing, bradycardia ramipril (Altace) Amlodipine (Norvasc), diltiazem (Cardizem), nifedipine (Procardia) Irbesartan (Avapro), losartan (Cozaar), valsartan (Diovan) Metoprolol (Lopressor) Nursing: complete entire regimen Nursing: do not exceed recommended dose in 24 hrs (tylenol max dose is 4g/24 hr), monitor for GI bleeding (anemia, melena), avoid alcohol Nursing: contraindicated in narrow angle glaucoma, administer with food to decrease GI irritation, gum/hard candy helps increase salivation + decrease dry mouth Nursing: abrupt withdrawal can lead to HTN or dysrhythmias, assess for increased fluid volume, monitor BP and HR Carvedilol (Coreg), labetalol Antilipidemic: decreases LDL, triglycerides, and total cholesterol. Increases HDL MOA: E.g.: HMG-CoA reductase inhibitor – inhibits Atorvastatin (Lipitor), rosuvastatin enzyme HMG-CoA which is a catalyst in (Crestor), simvastatin (Zocor) synthesis of cholesterol Bile acid sequestrants – binds cholesterol in GI Cholestyramine (Questran) Cholesterol absorption inhibitor – inhibits Ezetimibe (Zetia) absorption of cholesterol in small intestine Antineoplastics: destroy or decrease growth of neoplastic cells SE: nausea, vomiting, abdo cramps, diarrhea, constipation Nursing: avoid grapefruit juice with HMG-CoA (increases toxicity) 51 MOA: E.g.: SE: renal + GI + skin problems, Alkylating agent – decreases DNA synthesis + Carboplatin (Paraplatin), cisplatin nephrotoxic, ototoxic, prevents replication (Platinol) alopecia Antimetabolite – decreases DNA synthesis + Fluorouracil, methotrexate (Mexate) metabolism Antituberculars: decreases cough, sputum, fever, night sweats. Produces negative culture for M. tuberculosis MOA: decreased mycobacterial cell wall E.g.: isoniazid, rifampin, ethambutol SE: peripheral neuropathy, Nursing: avoid aluminum containing synthesis hepatotoxicity, diarrhea, optic antacids within 1 hr of isoniazid, neuritis rifampin will produce orange colored urine Antivirals: prevents or decreases severity of viral infection (not a cure) MOA: Decreases entry of virus into a host or E.g.: oseltamivir (Tamiflu) for Influenza SE: anorexia, nausea, Nursing: C&S needed before giving decreases viral DNA synthesis A, acyclovir (Zovirax) for herpes vomiting, diarrhea, headache, med simplex/genital/zoster/ varicella vaginitis Bronchodilators: promote bronchial expansion, increases transfer of gases, decreases wheezing/SOB MOA: E.g.: SE: increases HR, decreases Nursing: wait 1-5 mins between Xanthines – relax bronchial smooth muscle, Theophylline BP, palpitations, dizziness, inhalers (use bronchodilator first), decrease spasms headache, weakness, dry rinse mouth after use, encourage Anticholinergics – decrease action of Ach Ipratropium (Atrovent) mouth, urinary retention fluid intake to avoid dry mouth receptors in bronchial smooth muscle Leukotriene receptor antagonists – decrease Montelukast (Singulair) edema, bronchoconstriction, and inflammation Inhaled steroids – decrease local inflammatory Budesonide (Pulmicort), fluticasone response and edema, increase airway (Flovent) diameter Antisecretory agents: decrease gastric acidity and pain MOA: E.g.: SE: confusion, dizziness, Nursing: may increase anticoagulant H2 antagonist – decreases histamine at H2 Famotidine (Pepcid), ranitidine drowsiness, headache, effect of warfarin, administer 1-2 hrs receptors in parietal cells, leading to (Zantac) nephrotoxicity before or after antacids, do not crush decreased gastric sections PPIs PPI – decreases entry of H+ ions into gastric Omeprazole (Prilosec), lansoprazole lumen (Prevacid), pantoprazole (Protonix) Diuretics: increase urine output, decrease hypervolemia/BP/edema/ICP MOA: E.g.: SE: dehydration, orthostatic Nursing: monitor K level, give in Thiazide – decreases Na and Cl resorption in Hydrochlorothiazide, metolazone hypotension, decrease in morning to avoid sleep disruption (pt distal convoluted tubule and decreases Cl (Zaroxolyn) potassium (except in will be peeing after this med), change resorption in loop of Henle potassium sparing diuretic), position slowly to avoid orthostatic Loop – decreases Na and Cl resorption in Furosemide (Lasix), bumetanide fluid + electrolyte imbalance hypotension ascending loop of Henle and distal tubule (Bumex) 52 Potassium sparing – acts in distal tubule, decreases action of aldosterone, increases Na excretion and retains K Spironolactone (Aldactone) Hypoglycemics (Oral): control blood glucose in T2DM MOA: E.g.: SE: hypoglycemia Sulfonylurea – stimulates beta cells to release Glimepiride (Amaryl), glipizide insulin (Glucotrol), glyburide (Micronase) Biguanides – increase sensitivity to insulin, Metformin (Glucophage) increases binding of insulin to receptor Meglitinides – increase release of insulin in Repaglinide (Prandin) pancreas Laxatives: decrease constipation MOA: E.g.: SE: cramps, fluid and Bulk-forming – increase bulk and stimulate Psyllium (Metamucil) electrolyte imbalance peristalsis Stool softeners – water and fat enter feces to Docusate sodium (Colace) soften and decrease drying of stool Stimulant – irritates = rapid propulsion of Bisacodyl (Dulcolax), sennakot contents Saline osmotic – draws water in and Milk of magnesia, sodium phosphate stimulates peristalsis fleet Opioids: decrease transmission of pain impulse MOA: combine with opioid receptors in CNS E.g.: codeine, fentanyl, hydrocodone, SE: decreased RR, sedation, hydromorphone, methadone, constipation, nausea, morphine, oxycodone drowsiness Opioid antagonist: reverses opiate induces CNS depression and decreased respiratory function MOA: displaces opioid at respiratory receptor E.g.: naloxone (Narcan) SE: nausea, vomiting, v fib site via competitive antagonism Anxiolytics, sedatives, hypnotics: decrease anxiety, induce sleep, and ease alcohol withdrawal MOA: E.g.: SE: decreased mental Benzodiazepines – increase action of GABA Short acting: alprazolam (Xanax) alertness, hypotension, inhibitory neurotransmitter Medium acting: lorazepam (Ativan) dizziness, headache, euphoria Long acting: chlordiazepoxide (Librium), clonazepam, diazepam Nursing: contraindicated in T1DM, monitor for hypoglycemia Nursing: contraindicated in nausea + vomiting, abdo pain or abdo obstruction, administer at bed time, encourage an increase in fluid intake, saline osmotic is most rapid acting Nursing: monitor for respiratory depression (keep naloxone available for toxicity) Nursing: monitor for opioid withdrawal Nursing: barbiturates are rarely used due to greater dependence, avoid alcohol and caffeine Nonbarbiturates – CNS depressant effect Buspirone (BuSpar), diphenhydramine (Benadryl), zolpidem (Ambien) Antidepressants: lift depressed mood, decrease S/S of panic and ADD 53 MOA: TCA – decrease reuptake of norepinephrine and serotonin into presynaptic nerve terminals SSRI – decrease reuptake of serotonin into presynaptic nerve terminals E.g.: Amitriptyline (Elavil), nortriptyline (Pamelor) SE: anticholinergic effects, sexual dysfunction, dizziness, headache, weight gain + appetite increase Nursing: assess for SI (especially when energy + mood increases), meds need to be used for a minimum 2-6 wks to avoid serotonin syndrome, do not d/c med abruptly, avoid giving TCA to narrow angle glaucoma pt, avoid food containing tyramine with MAOI SE: EPS (dystonia, akathisia, parkinsonism, tardive dyskinesia), sedation, hypotension, sexual dysfunction, anticholinergic effects Nursing: effects may take 2 wks to see, increase fluid and fiber to avoid anticholinergic effects, avoid caffeine, administer meds to decrease EPS S/S (benztropine, clonazepam, diazepam) SE: drowsiness, dizziness, nausea, vomiting, headache, hypotension, respiratory depression Phenytoin – ataxia, gingival hyperplasia Nursing: increase dose gradually, provide oral hygiene, avoid alcohol and other CNS depressants, seizures occur with abrupt withdrawal Citalopram (Celexa), fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft) Phenelzine (Nardil) MAOI – decrease breakdown of norepinephrine, dopamine, and serotonin Atypicals – increase effects of dopamine, Bupropion (Wellbutrin), mirtazapine serotonin, and norepinephrine (Remeron), venlafaxine (Effexor) Antipsychotics: decrease agitated behaviour and psychotic symptoms MOA: E.g.: Typical – for positive symptoms Haloperidol, prochlorperazine Atypical – for negative symptoms Clozapine (Clozaril), olanzapine (Zyprexa), quetiapine (Seroquel), risperidone (Risperdal) Antiseizure: decreases occurrence, frequency, and severity of seizures E.g.: carbamazepine (Tegretol), gabapentin (Neurontin), phenytoin (Dilantin), phenobarbital (Luminal), valproid acid (Depakote), lamotrigine (Lamictal), levtiracetam (Keppra), topiramate (Topamax) Antiparkinsons: restores dopamine and acetylcholine balance MOA: E.g.: Dopaminergic – increases dopamine Amantadine (Symmetrel), bromocriptine (Parlodel), carbidopalevodopa (Sinemet) Anticholinergics – decreases excess Benztropine (Cogentin) cholinergic activity Anti-Alzheimer’s: decreases S/S of dementia MOA: increase in acetylcholine levels E.g.: donepezil (Aricept), glantamine (Reminyl) Antidysrhythmics: decrease abnormal electrical conduction MOA: E.g.: Class 1 (calcium ion antagonist) – slows Procainamide (Procanbid), lidocaine conduction, used for ventricular dysrhythmias (Xylocaine) SE: hypotension, increased HR, Nursing: do not d/c abruptly (can fatigue, nausea, vomiting, dry cause Parkinsonian crisis) mouth, constipation, toxicity = muscle twitching SE: anorexia, nausea, vomiting, headache, dizziness, insomnia Nursing: use cautiously for pts with COPD, teach that this med is not a cure SE: heart failure, hypotension, anticholinergic effects, diarrhea, new dysrhythmias Nursing: use infusion pump if giving IV med, monitor HR before administration 54 Class 2 (beta adrenergic blocker) – decreases Metoprolol (Lopressor) cardiac excitability, output, and workload, decreases HR + BP Class 3 (potassium channel blocker) – slows Amiodarone (Cordarone) HR + conduction, used for ventricular and supraventricular dysrhythmias Class 4 (CCB) – decreases entry of Ca into Verapamil (Calan), diltiazem myocardial cells, decreases SA and AV node (Cardizem) conduction, used for afib and SVT Cardiac Glycosides: increase force of contraction, decrease HR, increase cardiac output MOA: inhibits Na, K-ATP = increases cardiac E.g.: digoxin (Lanoxin) SE: low HR, drowsiness, intracellular Ca and increases myocardial fatigue, weakness contractility Cardiac Stimulants: increase HR MOA: stimulate alpha and beta receptors to E.g.: atropine sulfate, dobutamine, SE: dysrhythmias, increased increase HR and contractility norepinephrine (Levophed), HR, headache, anticholinergic epinephrine (Adrenalin) effects Coronary Vasodilators: dilate arteries, decrease preload + afterload, decrease myocardial O2 consumption MOA: blocks Ca channel or relaxes smooth E.g.: amlodipine (Norvasc), nifedipine SE: orthostatic hypotension, muscle to treat angina and mild HTN (Procardia), nitroglycerine (Nitro), increased HR, headache, verapamil (Calan) dizziness, nausea, vomiting, flushing Nursing: give loading dose first, assess apical pulse before giving med Nursing: continuous ECG when giving IV med Nursing: put oral nitroglycerin under tongue and avoid sudden standing 55