GI drugs and antiemetics

what is the digestive system?

breaks down food into smaller components » stomach mixes food with digestive enzymes and acids » absorption of vitamins, minerals, nutrients into bloodstream

what is gastric acid production?

• chief cells » pepsinogen

• parietal cells

  • secrete hydrochloric acid » food breakdown

  • secrete intrinsic factor » B12 absorption

  • activates pepsinogen » protein breakdown

  • kills ingested microbes

• gastric juices of these cells are the most acidic » stomach needs protective layer » bicarbonate

what is the pathology of peptic ulcer disease?

• increased gastric secretion and lack of protection from bicarbonate » erosion of mucosal layer of GI tract from » inflammatory response

• peptic » lesion in stomach (gastric) or small intestine

what are the risk factors of peptic ulcer disease?

• H.Pylori

• stress

• smoking » increases gastric secretions

• caffeine

• meds

  • NSAIDS » ibuprofen

  • antiplatelets » aspirin

  • corticosteroids » solumedrol

• family hx

how to manage PUD and GERD?

• reduction to exposure to stress/stress causing and acid producing situations

• reduce alcohol intake

• smoking cessation

• encourage diet and exercise

• avoid NSAIDS » especially on empty stomach and family hx

• small meals, avoid eating before bedtime » elevate HOB

• weight control

what are the goals for treating PUD?

• infected with H.Pylori » eradicate bacteria

• suppress acid production

• provide immediate relief of symptoms

• promote healing

• prevent recurrence

what is the pharmacological management for PUD?

• proton pump inhibitors (PPI)

• H2 receptor antagonists

• antacids » contain bicarbonate » help buffer stomach

• antibiotics » infected with H.Pylori

• miscellaneous drugs

what is H.Pylori?

• main cause of PUD

• increases risk for gastritis and GI cancers

• gram negative bacteria

• found in stomach and small intestines

• NSAIDS and H.Pylori » promote ulcers by 3.5 times

• neutralizes acidity in stomach

• sticks to GI mucosa through adhesions

• if not treated » remain active for life

what is H.Pylori treatment?

• needs combination of antibiotics and antacids » antacids alone have minimal to no effect

• PUD without H.Pylori SHOULD NOT be treated with antibiotics » overuse of antibiotics builds resistance to bacteria » pt tested prior to receiving treatment

• antibiotics prescribed 7-14 days

• once eradicated » re-infection is common

what is the pathology of GERD?

• condition where acidic contents of stomach move upward to esophagus

• weak lower esophageal sphincter (LES)

• failure of sphincter to close » upward regurgitation of stomach acids

• acidic contents » irritation/inflammation of esophagus

• causes symptoms of burning and belching

• can occur in adults and infants

• untreated » ulcers, esophagitis, strictures

• persistent disease » surgical intervention

what are PPIs?

• proton pump inhibitors

• blocks secretion of hydrochloric acid

• for short term PUD and GERD

• longer duration than H2 antagonist » reduce acid secretion to greater extent than H2 antagonist

• heals 90% of all ulcers = 4-8 weeks

• average treatment = 4 weeks

• ex: omeprazole (prilosec), 20-60 mg/day

what are the nursing considerations for PPIs?

• available OTC

• take 20-30 mins before first big meal of the day

• several days of therapy needed for symptom relief

• ALL PPI have similar efficacy

• ALL PPI have similar side effects

  • HA

  • ABD pain

  • diarrhea

  • N/V

• decreases calcium absorption » increased risk of osteoporosis related fractures » calcium supplement with long term therapy

what are H2 Antagonists?

• suppresses acid secretion from H2 receptors in stomach

• decreases acidity of parietal cells

• takes longer to heal ulcers vs PPI = 6-12 weeks

• available OTC

• famotidine (pepcid), PO 20-40mg/day for active ulcers, 20mg BID for GERD

what are the nursing considerations for H2 antagonists?

• taking high doses, PMH of CKD or liver failure » increased confusion, restlessness, hallucinations, depression

• numerous drug-drug interactions, inhibits hepatic drug metabolizing enzymes » tagamet » used less frequent

• avoid antacids » reduces absorption of H2 antagonist

what are antacids?

• inexpensive and OTC

• provide temporary relief

• rapid/short acting symptom relief

• does not heal ulcers or eradicate H.Pylori

• combination drugs available with antacids and H2 antagonists » mylanta

• ex: aluminum hydroxide (alternaGEL), PO 600 mg TID-QID

what are the nursing considerations for antacids?

• contain minerals that may be absorbed in circulation » sodium, calcium, magnesium

• caution in patients with CKD » accumulation of minerals

• question pt taking antacids while on sodium restricted diet

• antacids with calcium » constipation or kidney stones » monitor BUN/CR

• hypercalcemia » monitor calcium levels

• calcium containing antacids along with milk products » milk-alkali syndrome

what is sucrafate?

• miscellaneous drug for PUD

• carafate

• produces thick gel that coats ulcer

• does not affect gastric secretion

• common side effect » constipation

• disadvantage » take QID

what is misoprostol?

• miscellaneous drug for PUD

• cytotec

• inhibits gastric secretion

• stimulates production of protective mucus

• primarily used as prevention for pt taking high doses of NSAIDS or corticosteroids

• common side effect » diarrhea, ABD cramping

• pregnancy category X » DO NOT TAKE

what is reglan?

• miscellaneous drug for PUD

• short term therapy of PUD when first line of drugs failed

• muscle in upper intestine contract » faster gastric emptying, blocks regurgitation to esophagus

• common side effect » CNS changes » drowsy, fatigue, confusion, insomnia

• black box warning » tardive dyskinesia with long term therapy

what are the lifespan considerations?

• GERD rare in children

• GERD treated the same in children and adults » non=pharmacological and pharmacological measures

• PPI dosage higher in children vs adults

• antacids and H2 antagonist dosage is smaller in children vs adults

what is nausea?

• unpleasant sensation accompanied by weakness, diaphoresis, increase saliva production, and in some cases dizziness

• may lead to vomiting (emesis)

what is the pathology of nausea and vomiting?

• reflex defense mechanism of body » gets rid of toxins

• communication starts in GI tract » signals sent to various receptors » medulla “vomiting center of brain”, inner ear, cerebral cortex

• wave like contractions propel GI contents upwards and expelled orally

what is the primary goal for N/V?

• identify the cause

  • infection

  • food poisoning

  • nervousness, stress, anxiety

  • pain

  • motion sickness

  • anesthesia

  • migraines

  • head trauma

  • DM

  • inner ear disordders

  • sensory disturbances

  • pregnancy

  • meds » chemotherapy

what are the potential risk for N/V?

• non-compliance of meds

• dehydration

• weight loss » malnutrition

• pH changes

• death if untreated

how are chemotherapy patients at increased risk of N/V?

• N/V from cytoxic effects of chemotherapy drugs » irritate stomach lining » disrupt normal function of GI tract » severe dehydration, electrolyte imbalance, nutritional deficiencies

• experience changes in appetite » poor overall nutritional status

• monitor for dehydration » interventions » antiemetic, hydration therapy, nutrition support

how are geriatric patients at increased risk of N/V?

reduced gastric motility, chronic illness, meds, health conditions, decreased sensation of thirst » increase risk of dehydration » hypotension, kidney dysfunction/failure, electrolyte imbalances

how are infants/children at increased risk of N/V?

• higher metabolic rate, bodies contain greater percentage of water

• severe N/V when caused by viral infection or GI illnesses » increase risk of dehydration » electrolyte imbalance, hypotension, shock

• cannot communicate symptoms » monitor for signs of dehydration » dry mouth, lethargy, decreased urine output

how are pregnant women at increased risk of N/V?

• during first trimester experience morning sickness

• N/V can become more severe » hyperemesis gravidarum » increased risk of dehydration, weight loss, electrolyte imbalance

what are antiemetics?

• anticholinergics and antihistamines

  • hydroxyzine (vistaril)

  • meclizine (antivert)

  • scopolamine (transderm scop)

• benzodiazepine

  • lorazepam (ativan)

• phenothiazines and dopamine receptor antagonists

  • metoclopramide (reglan)

• serotonin receptor antagonists

  • ondansetron (zofran)

what are common side effects of antiemetics?

suppress ability to produce secretion » dry mouth, decreased urine output, cotton mouth (reduced salivary flow)

what is the pharmacotherapy for N/V?

• depending on causes and severity » multiple antiemetics may be required

• OTC options available for mild symptoms

• herbal options » peppermint and ginger