Pharmacology Chapter 22

Drugs to cause diarrhea

**page 367

ondansetron (Zofran) 5HT 3 Receptor antagonists

1. Abdominal pain 2. constipation 3. fatigue 4. headache

metoclopramide (Reglan) (4) (dopamine antagonist)

1. Drowsiness 2. fatigue 3. increased depression 4. restlessness

phenothiazines (2 plus 2 drugs)

1. Inhibit vomiting reflex pathways 2.sedating effects help control nausea Drugs: promethazine (Phenergan) prochlorperazine (Compazine)

What to do after administering drugs for constipation?

1. assess abdomen 2. monitor for BM, quality of BM, and side effects

prochlorperazine (compazine) (phenothiazine)

1. blurred vision 2. constipation 3. dizziness 4. dry eyes and mouth 5. muscle spasms 6. jitteriness 7. mouth puckering 8. neutropenia

dopamine antagonists 1 + 1 drug

1. causes food to move more quickly through digestive tract 2. metoclopramide (Reglan)

promethazine (Phenergan) Phenothiazines (8)

1. confusion 2. disorientation 3. dizziness 4. dry mouth 5. n/v 6. rash 7 sedation 8 respiratory depression 9. neutropenia

antihistamines (3) + 2 drugs

1. decrease N/V caused by opiates or motion 2. depress inner ear excitability 3. reducing vestibular stimulation (balance) 4. meclizine (Antivert and Dramamine)

5HT3 receptor antagonist (2 + 1 drug)

1. decrease N/V with chemotherapy 2. block serotonin receptors 3. ondansetron (Zofran)

Anticholinergic Drugs (3) + 1 drug

1. decrease vomiting reflex 2. stops intestinal cramping 3. decreases vestibular input to CNS (Balance) 4. scopolamine (L-hyoscine)

common side effects of antiemetics (11)

1. insomnia 2. diplopia (double vision) 3. tinnitus 4. hypertension 5. photosensitivity 6. EKG 7. tachy/brady 8. urine color changes 9. urinary retention 10. anxiety 11. depression

Constipation (3) characteristics

1. less than three bowel movements a week 2. stools are hard and dry, difficult to eliminate 3. bowel movements can be painful

GI functions (4)

1. taking in fluids and nutrients 2. breaking down food into usable forms 3. absorbing useful nutrients and fluids 4. eliminating waste products

Adverse effects of antiemetics (6)

1.neuroleptic malignant syndrome 2.coma 3.seizures 4.tardive dyskinesia 5.respiratory depression 6.tissue necrosis (IV PUSH undiluted promethazine)

types of antiemetic drugs (5)

1.phenothiazines, 2.anticholinergics 3.antihistamines, 4.5HT3-receptor antagonists and 5.dopamine receptor antagonists

teaching for antiemetics

1don't drive heavy machinery or a car 2change positions slowly 3use sunscreen and wear protective clothing 4educate about NMS and tardive dyskinesia 5Eat fiber and increased fluids to prevent constipation 6 assess for infection (temperature 7. check with dr before taking OTC drugs 8. don't use alcohol or other CNS depressants 9. educate them about urine color changes (prochlorperazine) Compazine 10 use frequent mouth rinses and oral care for dry mouth 11. Do not double dose

Causes of constipation (10)

1low fiber diet 2lack of physical activity 3stress 4pregnancy 5medical diseases 6mental health issues 7decreased fluid intake 8delaying going to the bathroom 9misuse of laxatives 10other drugs affecting nerve activity of colon and fluid balance

Acute diarrhea (3)

3 or more loose stools in 24 hours last <2 weeks Most last <72 hours

what are adverse effects of antidiarrheals?

FiberCon can cause intestinal obstruction Toxic megacolon-Fever, abdominal pain, increased heart rate and dehydration

What to do before administering drugs for constipation?

Look at drugs, including OTC;s ask about bowel habits assess abdomen baseline VS, weight Check BS if diabetic give oral fluid (6 oz) with oral doses Antacids must be one hour apart

Older Adult considerations for constipation

Most drugs are safe for older adults remind them to follow directions encourage them to increase fluid intake

Adverse reactions

RARE=allergic reactions

bulk forming laxatives (Metamucil)(2)

add bulk to stool Can be used long term (more than one week)

Emmolient/Stool softeners (Colace)

allow stool to mix with fatty substances

Three types of antidiarrheal drugs

antimotility adsorbent/absorbent antisecretory

ped considerations for antiemetics

assess for muscle spasms watch for balance disturbance (used for cancer chemo) teach parents to read drug label

pregnancy considerations for antiemetics

avoid when breastfeeding

Why don't we want to give drugs for an infection from bacteria or parasites

can make the condition worse

osmotic laxatives (fleet's) (MOM) GoLYTELY Mirilax (Saline)

cause retention of fluid in the bowel Can cause electrolyte imbalances when used too often

interventions before giving antiemetics

causes of N/V history of depression (reglan) dilute for IV Push

interventions after giving antiemetics

check LOC check sedation (particularly with older adults assess N/V if they cause GI symptoms for the patient, give them with food milk or a full glad of water

lubricants (to treat constipation) glycerin or castor oil + (five adverse events

coat surface of stool and help hold water ADVERSE EVENTS 1confusion,2 irreg heartbeat, 3cramps, 4rash, and 5unusual weakness or tiredness

antimotility drugs

decrease peristalsis

how do antisecretory drugs work?

decrease secretion of intestinal fluids and slow bacterial activity

antisecretory drugs (2)

decrease secretions in the GI tract and treat diarrhea

Motility disorder 1 + 2 examples

decreased contact time IBS diabetic neuropathy

Exudative 2 charact. + example

defective colonic absorption outpouring of mucus/blood Crohn's

side effects of drug therapy for constipation (8)

diarrhea skin rash stomach cramps abdominal distention nausea gas reflux headache

consult doctor for constipation when 4

doens't respond to treatment symptoms are severe last more three weeks or complications occur (bleeding) **Rule out colon cancer**

What should be taught when giving drugs for constipation (6)

drink 1500-2000 mL of fluid take with several oz of fluid 6-8 they should only be used short term space antacids from these meds (space at least one hour) call dr if constipation is not relieved, signs of fluid imbalance, or rectal bleeding

meclizine (Antivert) side effect (antihistamine)

drowsiness

stimulant laxatives (Dulcolax) + adverse reaction

increase peristalsis May cause hypokalemia ADVERSE-dysrhythmias

secretory diarrhea 1 + 2 examples

increased secretion of electrolytes Ecoli ileal resection (surgery)

Older adult considerations for antiemetics

increased side effects of confusion and dizziness, shaky hands, and balance disturbance, and heat-related disorders May need lower dose

diarrhea (3)

is a symptom can cause dehydration can cause electrolyte imbalance

Chronic diarrhea (3)

lasts longer than two weeks may not have a stool every day most common cause is enteritis

What to do before giving antidiarrheals?(4)

list of drugs (including otc) weight and VS Check for dehydration listen to abdomen

Types of diarrhea 4

osmotic secretory exudative motility disorder

What to do after giving antidiarrheals

reassess watch for signs of megacolon monitor for change in VS,

absorbent drugs

remove substances that cause diarrhea

how do adsorbent/absorbent drugs work

remove substances that cause diarrhea from teh body

Pregnancy considerations for constipation

safe to use during pregnancy fleets should not be used

How do antimotility drugs work?

slow the movement of stool through the bowel, allowing for more time for water and salt to be absorbed

Intended responses for drug therapy for constipation

soften, pass stool relieve or prevent constipation

osmotic diarrhea 1 + 2 examples

unabsorbed solutes lactose deficiency mg excess

what are side effects of antidiarrheals?2

uncommon for healthy adults constipation

When would drugs for constipation be contraindicated

undiagnosed abdominal pain r/t risk of increased peristalsis and risk of bowel perforation

Pediatric considerations for constipation

usually 1/2 the dose of adults follow specific instructions from the prescriber

What do we need to educate clients with diabetes about using bulk forming drugs?

watch for those that contain sugar