Summary NSG 251 Exam 3 Drugs Study Guide

DRUG NAME

Medication(s): sulfamethoxazole-trimethoprim
Mechanism:
 One
 Two
 Three
Uses:
 One
 Two
 Three
Interactions/Contraindications:
 One
 Two
 Three
Adverse Effects:
 One
 Two
 Three
Nursing Process:
 One
 Two
 Three

,ANTIACIDS: Gastro / Acid-Controlling

Mechanism:
 Base (alkaline) mediated inhibition of the protein-digesting ability of pepsin
 Increase in protective lining of the stomach
 Increase tone of the lower esophageal (cardiac) sphincter which minimizes acid reflux
o At low doses: Stimulate mucus production
o At low doses: Stimulate prostaglandins
o At low doses: stimulate bicarbonate
Uses:
 Symptomatic relief of stomach pain and reflux “heartburn”
Interactions/contraindications:
 Allergy
 Renal failure: DO NOT USE ANY MAGNESIUM BASED PRODUCT
 Caution: Electrolyte disturbances: hypercalcemia
 Caution: bowel obstruction: magnesium
 Interactions: common mechanisms
o Adsorption and chelation: other drugs are bound to or chemically inactivated reducing or preventing their
therapeutic effects
o Increased stomach pH: increases absorption of basic drugs (benzodiazepines, sympathomimetics, valproic acid)
and decreases absorption of acid drugs (allopurinol, thyroid hormones, digoxin, antihistamines, corticosteroids,
digoxin, aspirin, isoniazid)
o DO NOT GIVE WITH quinolone antibiotics: blocks antimicrobial effect
Adverse effects:
 Magnesium: diarrhea
 Aluminum and calcium: constipation
 Calcium: kidney stones
 Systemic alkalosis with OVER USE of any antacid, especially sodium bicarbonate (baking soda)
 Calcium can cause acid rebound
 Chronic high dose calcium antacids can cause milk-alkali syndrome
 Hypercalcemia, headache, nausea, and alkalosis
 Aluminum antacids can lead to hypercalcemia and hypophosphatemia
 Calcium antacids can cause gas and belching
Nursing Process:
 Conduct appropriate history and physical exam with focus of GI tract disorders, bowel pattern, GI related pain
 Review current medications and review any available labs
 Assess for HTN, heart failure, presence of edema: antacids are high in sodium
 Long-term self-medication with antacids may be masking manifestation of a serious underlying condition (such as a
bleeding ulcer, or cancer): encourage occasional use only, if continued use is necessary, advise patient to see their HCP
after 2 weeks of use
 Separate antacids by 2 hours from other meds
 Pregnancy category A
 Many antacids are high in sodium: read labels if the patient is on a sodium restriction
 Calcium based antacids may also be used a source of calcium (as for osteoporosis treatment, prevention)
 Liquid antacids must be shaken prior to dosing
 Assess/report: prolonged constipation/diarrhea, increasing abdominal pain/distension, hematemesis or black tarry
stools

,HISTAMINE 2 RECEPTOR ANTAGONIST (H2 BLOCKERS) – Gastro / Acid-Controlling

Medication(s): cimetidine
Mechanism:
 Competitively block the H2 receptor on parietal cells making them less responsive to the effects of histamine,
acetylcholine, and gastrin resulting in reduced hydrogen ions and thereby increasing the pH of the stomach and relief of
symptoms
Uses:
 Reduce but do not stop acid secretion in the treatment of GERD, PUD, esophagitis
 Control of upper GI bleeding
 Prophylaxis of stress ulcers
Interactions/contraindications:
 Allergy
 Caution: liver/kidney: may need dose adjustment
 Interactions: cimetidine has A TON of interactions with other medications: always look at the patient’s medication
profile prior to administration
o Recommendation to switch to famotidine (Pepcid) which has very few drug interactions
Adverse effects:
 Good safety profile
 Confusion and disorientation may occur in the older adult
 Cimetidine may cause impotence and gynecomastia
 Hypotension with IV administration, especially if infused too quickly
 Headache
 Diarrhea
 thrombocytopenia
Nursing Process:
 Conduct an appropriate history and physical exam with focus of GI tract disorders, bowel pattern, GI related pain
 Assess/report: bruising, fatigue, diarrhea, black tarry stools, sore throat, or rash to the HCP
 Monitor for mental status changes
 Monitor renal and liver labs
 Take cimetidine with food
 Smoking decreases effectiveness of H2 blockers: encourage patient to reduce use or quit
 H2 blockers should be taken 1 to 2 hours BEFORE an antacid
 Cimetidine may also be used, with other drugs, to treat allergic reactions

, PROTON PUMP INHIBITORS (PPIs) – Gastro / Acid-Controlling

Medication(s): omeprazole (several in class end in “prazole”)
Mechanism:
 Bind directly to the proton pump causing a total blockage of all hydrogen ion secretion from parietal cells
 This stops 90% of acid secretion for 24 hours: this is achlorhydric (without acid)
o Can lead to bacterial overgrowth
o Can lead to intestinal metaplasia (a nonadaptive cellular/tissue change)
o Can lead to hip fractures
 Does not affect food absorption
Uses:
 First line therapy for esophagitis, GERD (poorly responsive to other treatments such as H2 blockers), short term
treatment of active gastric/duodenal ulcers, NSAID induced ulcers, and stress ulcer prophylaxis. Long term maintenance
of healing of erosive esophagitis, and pathologic hypersecretory states
Interactions/contraindications:
 Allergy
 Interaction: increase serum levels of diazepam and phenytoin
 Interaction: increase risk of bleeding with warfarin
 Interferes with absorption of digoxin, ampicillin, and iron
 Slowed absorption when given with sucralfate
 Food slows absorption
Adverse effects:
 Over prescribing of PPIs may be linked to GI tract infections due to loss of normal acid mediated microbial protection:
FDA: BOX WARNING: Clostridioides (formerly Clostridium) difficile
 Osteoporosis from inhibition of stomach acid necessary for calcium absorption, also PPIs may speed up bone
demineralization: FDA: BOX WARNING: wrist, hip, and spine fractures, pneumonia, and magnesium depletion
 Possible link between PPIs and dementia
Nursing Process:
 Complete appropriate history and physical exam, focusing on GI:
 Ability to swallow (some capsules are LARGE)
 Some capsules can be opened and given with small amount of applesauce: check prior to
administration
 Joints ROM, muscle strength, history of fractures without trauma
 All PPIs can be used with antibiotics to treat H. pylori infection
 Can be given orally or capsules opened/diluted in water and given per NG or PEG
 NOTE: pantoprazole granules must be given through a NG tube larger than 16 French – clogging will occur with
smaller tubes
 Some PPIs come in IV formulation
 Give on an empty stomach 30-60 minutes before meals to enhance absorption
 For patients with GERD: teach to avoid black pepper, caffeine, alcohol, harsh spices, and extremes in food temperature