Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHARM ORAL 2021 > Antiemetics/GI drugs > Flashcards

Antiemetics/GI drugs Flashcards

1
Q

metoclopramide (reglan): class + use

A
  • class
    • Benzamide (PABA derivative)
    • Antiemetic
    • prokinetic/gastrokinetic
    • Dopamine 2 receptor antagonist
    • 5HT4 receptor agonist
  • use
    • Preop to decreases gastric volume
    • Prevent PONV
    • Tx Opioid induced N/V
    • Used to improve drug absorption in people with slow gastric emptying
    • Tx for GERD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

metoclopramide (reglan): MOA

A
  • Dopamine 2 receptor antagonist acting centrally on CRTZ (crosses BBB) and peripherally to increase mobility of esophagus, stomach, and intestine
  • Increase Ach release via 5-HT4 receptor stimulation = increase GI tract mobility
  • Contraction of LES and gastric fundus, increased gastric and small intestine motility, decreased muscle activity in pylorus and duodenum
  • 5HT-4 agonist to increase cAMP to increase peristaltic activity
  • Weak 5-HT3 receptor antagonist (at high doses might enhance anti-emetic effects)
  • Kinetic only NO change in gastric pH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

metoclopramide: PK

A
  • Onset: 1-3 mins
  • DOA: 1-2 hours
  • E1/2t: 2-4 hours
  • PB: 30%, primarily to alpha 1 glycoprotein
  • Vd: 2 - 4 L/kg
  • crosses placent and breast milk
  • Metabolism: hepatic
  • Elimination: Renal excretion, 40% unchanged
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

metoclopramide: SE

A
  • Extrapyramidal effects (contraindicated in Parkinson’s, caution in restless leg syndrome or other movement disorders)
  • Restlessness/Akathesia
  • Cramping → give slowly; over 3-5 mins
  • Increase lactation
  • hypotension/tachycardia
  • Dysrhythmias if used in conjunction with ondansetron (case reports)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

metoclopramide: cautions/contraindications/drug interactions

A
  • CAUTIONS
    • generally, avoid in bowel surgeries so you don’t stimulate gastric motility on fresh sutures
    • pheo - could cause hypertensive crisis
    • epiletpics or pts received drugs like to cause extrapyramidal reactions
  • CONTRAINDICATIONS
    • BOWEL OBSTRUCTION!
    • Parkinson’s
  • DRUG INTERACTIONS
    • inhbits plasma cholinesterase and prolonges effects of succ and mivacurium
    • may increase sedative action of CNS depressants
    • Do not administer with phenothiazine, butyrophenone, MAOIs, TCAs, or to pts with preexisting EPS
    • do not administer with droperidol - both blocking dopamine receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

metoclopramide: dose

A
  • Dose 10-20 mg IV slowly; 15-30 mins prior to induction (for pro-kinetic benefit)
  • Antiemetic beneift: administer post induction because It can cause restlessness
  • 0.15mg/kg to children post T&A to reduce PONV in PACU
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

droperidol: class + use

A
  • class
    • 2nd generation typical antipsychotic
    • dopamine receptor antagonist
    • butyrophenone (fluorinated derivative of phenothiazine)
  • use
    • antiemetic; reduce post-op N/V
    • sedative
    • antipruritic
    • antipsychotic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

droperidol: MOA

A
  • “Theoretically” occupies GABA receptors; reduces synaptic transmission and causes buildup of dopamine in the synaptic cleft
  • antiemetic effects come from blocking CRTZ from dopamine stimulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

droperidol: PK

A
  • Peak: 30 min
  • DOA: 12 hours
  • E 1/2 life: 1.7 -2.3 hrs
  • Highly PB
  • Vd: 2 L/kg
  • Metabolism: liver
  • Elimination: urine (75%); feces (22%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

droperidol: SE

A
  • Slow HR
  • Drowsiness (higher doses)
  • Hallucinations
  • Extrapyramidal symptoms (avoid in Parkinson’s)
  • neuroleptic malignant syndrome (tachycardia, alterations BP, fluctuating LOC, muscle rigidity, hyperthermia, rhabdomyolysis, autonomic instability= mirror MH)
    • Tx: Amantadine- dopamine agonist and with mild anti-cholinergic effects
  • QT prolongation and torsades de pointe (black box warning)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

droperidol: cautions/contraindications/drug interactions

A
  • Caution
    • **Black Box Warning**
      • Caution with patients at risk of developing QT syndrome (TCAs, erythromycin)
      • Must be monitored prior to and continued for 2-3 hrs
      • All patients get 12 lead prior to administration of droperidol
  • Contraindicated
    • Parkinson’s
    • QT prolongation agents (Class I & III antiarrhythmics)
    • known or suspected QT prolongation
  • Drug interactions
    • DO NOT give with metoclopramide
    • additive w/ CNS depressants (barbs, Benzos, opioids, ETOH, antipsychotics)
    • Hypotension with Inhaled Anesthetics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

droperidol: dose

A
  • Antiemetic dose: 0.625 mg – 1.25 mg IV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

ondansetron (zofran): class + use

A
  • class
    • 5-HT3 Receptor antagonist
    • antiemetic
  • use
    • Prevention and tx of PONV
    • **Not effective in motion sickness or PONV caused by vestibular stimulation**
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ondansetron (zofran): MOA

A
  • 5HT3 receptor antagonist blocking serotonin both peripherally on vagal nerve terminals and centrally in the CTZ
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

ondansetron (zofran): PK

A
  • Onset: 30 mins
  • DOA: 4-8 hours
  • E1/2t: 3-4 hours
  • PB 70%
  • VD: 2 L/kg
  • Metabolism: 95% hepatic metabolism
  • Elimination:
    • 5% unchanged in urine
    • ~60% as metabolites in urine, 25% feces
  • Cross BBB
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ondansetron (zofran): SE

A
  • NEURO:
    • Headache with rapid administration
    • Sedation
  • CV
    • Slight prolongation of QT
    • AV block (with co-administration with metoclopramide)
  • GI
    • diarrhea or constipation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

ondansetron (zofran): cautions

A
  • Caution
    • liver disease (metabolism by liver)
    • QT prolongation or administration with other QT prolonging drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

ondansetron (zofran): dose

A
  • Dose: 4 - 8 mg IV over 2 mins
    • debate over beginning of surgery vs end of surgery
      • **remember: works synergistically with dexamethasone (which is given at the beginning of the case)**
  • Pediatric: 0.05-0.15 mg/kg IV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

promethazine (phenergan): class + use

A
  • class
    • Phenothiazine
    • Dopamine receptor antagonist
    • H1 receptor antagonist
    • muscarinic antagonist
  • use
    • PONV
    • sedation
    • blood transfusion reaction
    • allergic reaction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

promethazine (phenergan): MOA

A
  • Dopamine antagonist in the CRTZ, giving antiemetic effect
  • H1 antagonist → blocking histamine from binding to H1 receptors → dec histamine mediated response in respiratory tract, GI & blood vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

promethazine (phenergan): PK

A
  • Onset: 5 min
  • DOA: 4-6 hours
  • Plasma half-life: 9-16 hours
  • Liver metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

promethazine (phenergan): SE

A
  • NEURO
    • sedation (may delay awakening)
    • anticholinergic effects (dry mouth, constipation, urinary hesitancy, tachycardia)
    • **extrapyramidal side effects
    • **neuroleptic malignant syndrome
  • CV
    • prolonged QT
      • (theoretically, however, more of a concern with increased dose and prolonged use)

**these SE are more of a concern with prolonged use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

promethazine (phenergan): cautions/contraindications

A
  • Contraindications
    • age < 2 - fatal respiratory depression/coma
    • Parkinson’s
  • Drug interactions
    • can potentiate sedative effects of anesthetics
    • may have intsensification of: anticholinergics, CNS depressants
    • may have reduction of effect: levodopa and dopamine agonists
    • avoid coadministration of QT prolonging drugs (amiodarone, erythromycin, quinidine)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

promethazine (phenergan): dose

A
  • 6.25-12 mg IV, up to 25 mg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

sodium citrate (bicitra): class + use

A
  • class
    • Non-particulate Antacid
      systemic alkalizer
  • Uses
    • preop to increase gastric fluid pH
26
Q

sodium citrate (bicitra): MOA

A
  • pH of 8.4
  • directly neutralization of gastric pH
  • metabolized into sodium bicarb (NaHC03) in the body raising systemic pH
  • Thought is that by increasing the gastric pH it will decrease the severity of aspiration pneumonitis in the high risk non fasted patent if aspiration of gastric fluid were to occur
27
Q

sodium citrate (bicitra): PK

A
  • pH 8.4
  • effective within 15 - 20 min
  • Metabolism: almost completely oxidized
  • Excretion: < 5% unchanged in the urine
28
Q

sodium citrate (bicitra): SE

A
  • unpleasant taste r/t to pH can cause N/V
  • increased gastric volume
  • may decrease gastric emptying (give with reglan
29
Q

sodium citrate (bicitra): cautions/contraindications

A
  • low Na diet
  • severe renal impairement (avoid only with long term use of bicitra)
  • should not be administered with aluminum containing antacids
30
Q

sodium citrate (bicitra): dose

A
  • 15-30ml of 0.3-mol per liter solution 15-30 mins before induction of anesthesia is effective in increasing gastric pH in pregnant and non-pregnant patients
31
Q

diphenhydramine (benadryl): class + use

A
  • class
    • first generation H1 receptor antagonist
  • use
    • mild allergy
    • motion sickenss
    • chemotherapy induced N/V
    • PONV
    • insomnia
    • Anti-pruritic
    • acute anaphylaxis - directed at blocking further histamine - mediated vasodilation and hemodynamic instability and respiratory compromise. Used in conjunction wiht epi (adjunt only….not adequate tx by Itself).
    • Prevention and Tx of allergic reaction/ hypersensitivity to allergens/other drugs/ blood products (given with epi)
32
Q

diphenhydramine (benadryl): MOA

A

competitively and reversibly blocks H1 receptors from histamine on the effector cell in the GI tract, blood vessels and respiratory tract → preventing effects of histamine peripherally (vasodilation, hypotension, tachycardia, bronchospasm, edema, itching)

33
Q

diphenhydramine (benadryl): PK

A
  • Onset: Rapid
  • DOA: 4 - 6hrs
  • Cmax/peak: 2 - 3 hours
  • E1/2t: 2 - 8 hrs, up to 13.5 in elderly
  • Pb: 78%
  • Vd: widely distributed
  • crosses BBB
  • excellent absorption
  • lipophilic
  • nonionized at physiologic pH
  • Metabolism:
    • significant first pass effect
    • extensive hepatic by CYP450
    • smaller degrees in the pulmonary and renal systems
  • Excretion: portion excreted unchanged in urine
34
Q

diphenhydramine (benadryl): SE

A
  • NEURO
    • sedative effects
    • parodoxical excitation in peds or elderly
  • CV
    • QT interval prolongation
  • RESP
    • thickening of secretions
  • ANTICHOLINERGIC EFFECTS
    • pupillary dilation, dry eyes, dry mouth, urinary hesitancy, constipation, hypotension, tachycardia
35
Q

diphenhydramine (benadryl): cautions/contraindications/drug interactions

A
  • Caution
    • administration near end of case can delay recovery from anesthesia
  • Contraindications
    • premi
    • neonate
    • breastfeeding mom
    • increased IOP
    • glaucoma
  • Drug interactions
    • may have additive effects with CNS depressants
    • may intensify anicholinergic effects of other drugs
36
Q

diphenhydramine (benadryl): dose

A
  • 10 - 50 mg IV q 6 - 8hrs
37
Q

cimetidine: class + use

A
  • class
    • selective H2 receptor antagonist
    • least potent
  • use:
    • PUD
    • GERD
    • chemoprophylaxis prior to induction of GA
38
Q

cimetidine: MOA

A
  • competitive antagonism of H2 receptors to suppress gastric acid secretion by parietal cells and decrease intracellular cAMP and secretion of H+ ions
  • does not affect gastric fluid already present
39
Q

cimetidine: PK

A
  • onset: 45 - 90 min
  • peak: 1 - 3 hrs with oral administration
  • DOA: 4hrs
  • E1/2t: 1.5 - 2.5 hrs
  • Pb: 20%
  • Vd: 0.8 - 1.2 L/kg
  • crosses placenta and BBB
  • rapid oral absorption
  • Metabolism:​
    • first pass metabolism - only 50% bioavailability
    • hepatic
  • Elimination: ~75% unchanged in urine (RF increases E1/2t)
40
Q

cimetidine: SE

A
  • common side effects
    • diarrhea
    • headache
    • fatigue
    • skeletal muscle weakness
  • NEURO
    • CNS toxicity (confusion, restlessness, agitation, headaches, dizziness)
  • CV
    • rapid IV administration may cause bradycardia and hypotension → give over 15 - 30 minutes
  • RESP
    • association with PNA - decreased gastric acidity = more bacterial colonization in stomach and secondary in lungs
  • GI
    • ​may have transient elevation in LFTs
  • MISC
    • gynecomastia
    • impotence
    • idosyncratic cases of myelosuppression, thrombocytopenia, neutropenia, anemia
    • serum B12 deficiency with long term use
41
Q

cimetidine: cautions/drug interactions

A
  • CAUTIONS
    • RF (prolonged E1/2t)
    • liver disease (elevation in LFTS)
    • asthma
      • H2 antagonists impair H3 receptors → enhanced histamine release → AVOID rapid admin of these agents esp when in combo with a histamine releaser
      • ​​may exacerbate bronchospasm with unopposed H1 bronchoconstriction
  • DRUG INTERACTIONS
    • absorption of drugs can be impaired from increased gastric pH
    • Inhibits CYP450 = prolonged effect of warfarin, diazepam, Lidocaine, Propranolol, morphine, CCB, TCAs, Phenytoin
42
Q

cimetidine: dose

A
  • 300 mg IV over 15-30 min, 1-2 hrs preop - ↓ in RF
  • 300 mg PO the night prior and morning of surgery
43
Q

ranitidine (zantac): class + use

A
  • selective competitive H2 receptor antagonist
44
Q

ranitidine (zantac): MOA

A
  • competitive antagonism of H2 receptors to suppress gastric acid secretion by parietal cells and decrease intracellular cAMP and secretion of H+ ions
  • does not affect gastric fluid already present
45
Q

ranitidine (zantac): PK

A
  • DOA: 1.5 - 2.6 hrs
  • Vd: 1 - 2 L/kg
  • Pb: 15%
  • Metabolism: hepatic
    • 75% for PO and 30% for IV
  • Excretion: kidneys
    • 27% unchanged for PO dose
    • 50 - 70% unchanged for IV dose (dec dose in RF)
46
Q

ranitidine (zantac): SE

A
  • generally well tolerated, very few adverse effects
  • NEURO
    • common side effects
      • diarrhea
      • headache
      • fatigue
      • skeletal muscle weakness
  • CV
    • rapid IV administration may cause bradycardia and hypotension → give over 15 - 30 minutes
  • RESP
    • association with PNA - decreased gastric acidity = more bacterial colonization in stomach and secondary in lungs
  • GI
    • ​may have transient elevation in LFTs
  • MISC
    • idosyncratic cases of myelosuppression, thrombocytopenia, neutropenia, anemia
    • serum B12 deficiency with long term use
47
Q

ranitidine (zantac): cautions/drug interactions

A
  • CAUTIONS
    • RF (prolonged E1/2t)
    • asthma
      • H2 antagonists impair H3 receptors → enhanced histamine release → AVOID rapid admin of these agents esp when in combo with a histamine releaser
      • ​​may exacerbate bronchospasm with unopposed H1 bronchoconstriction
  • DRUG INTERACTIONS
    • absorption of drugs can be impaired from increased gastric pH
    • decreases metabolism of drugs that undergo extensive hepatic metabolism: propranolol, diazepam
48
Q

ranitidine (zantac): dose

A
  • 50-100 mg IV over 15-30 min preop; ↓ in RF
49
Q

famotidine (pepcid): class

A
  • selective competitive H2 receptor antagonist (most potent)
50
Q

famotidine (pepcid): MOA

A
  • competitive antagonism of H2 receptors to suppress gastric acid secretion by parietal cells and decrease intracellular cAMP and secretion of H+ ions
  • does not affect gastric fluid already present
51
Q

famotidine (pepcid): PK

A
  • Onset: 30 min IV, 1-3 hours PO
  • DOA: 8-12 hrs
  • E1/2t: 3 hrs (↑ w/elderly & renal insufficiency)
  • PB: 20%
  • Vd: 1.1-1.4 L/kg
  • Metabolism:
    • 30 - 35% hepatic
    • extensive first pass effect (bioavailability 40 - 45%)
  • Elimination: 65 - 70% renal
52
Q

famotidine (pepcid): SE

A
  • generally well tolerated, very few adverse effects
  • NEURO
    • common side effects
      • diarrhea
      • headache
      • fatigue
      • skeletal muscle weakness
  • CV
    • interaction with cardiac H2 receptors (arrhythmias, bradycardia, hypotension, heart block)
  • RESP
    • association with PNA - decreased gastric acidity = more bacterial colonization in stomach and secondary in lungs
  • GI
    • ​may have transient elevation in LFTs
  • MISC
    • idosyncratic cases of myelosuppression, thrombocytopenia, neutropenia, anemia
    • serum B12 deficiency with long term use
53
Q

famotidine (pepcid): cautions/drug interactions

A
  • CAUTIONS
    • RF (prolonged E1/2t)
    • asthma
      • H2 antagonists impair H3 receptors → enhanced histamine release → AVOID rapid admin of these agents esp when in combo with a histamine releaser
      • ​​may exacerbate bronchospasm with unopposed H1 bronchoconstriction
  • DRUG INTERACTIONS
    • absorption of drugs can be impaired from increased gastric pH
    • decreases metabolism of drugs that undergo extensive hepatic metabolism: propranolol, diazepam
54
Q

famotidine (pepcid): dose

A
  • 20 mg IV, 15 min before surgery
    • over at least 2 min (can be given faster than ranitidine and cimetinde)
  • 40 mg PO, 1.5 - 3 hrs before surgery
55
Q

omeprazole (prilosec): class + use

A
  • class
    • Proton Pump Inhibitor (PPI)
    • anti-secretory
  • use
    • PUD with H. pylori
    • Hemorrhagic ulcers
    • PUD in patient who requires NSAID use
    • Can also be used pre-operatively for aspiration prophylaxis
56
Q

omeprazole (prilosec): MOA

A
  • prodrug
  • Suppress gastric acid secretion by irreversibly inhibiting the H+/K+-ATPase pump (final common pathway)
    • Acid suppression lasts 3-5 days after each dose
      • New enzyme must by synthesized – can take weeks to return to baseline
57
Q

omeprazole (prilosec): PK

A
  • Prodrug converted to active drug in parietal cell canaliculus
  • Rapid absorption
  • peak plasma levels: 0.5 - 3.5 hrs
  • short half life
  • PB: 95
  • Crosses placenta and BBB
  • Hepatically metabolized by CYP2C19, 3A4
  • Most effective after 2-3 doses (decreases acid production by 90%)
  • Elimination:
    • 77% metabolites excreted in urine
    • 23% feces
58
Q

omeprazole (prilosec): SE

A
  • Well tolerated in the short term (<4-8 weeks)
    • “Take the lowest possible dose for the shortest possible time”
  • Headache, dizziness, drowsiness, abdominal pain, constipation, diarrhea, flatulence
  • Fractures/osteoporosis (long term use)
  • Acid rebound
  • Low magnesium - tetany, NM dysfuntion
  • Altering pH in GI tract
    • Associated with pneumonia (careful in COPD pts.)
    • C. difficile infections
  • Gastric cancer/carcinoid tumor (in rats only- FDA concluded NOT in humans)
59
Q

omeprazole (prilosec): cautions/drug interactions

A
  • CAUTIONS
    • AE with prolonged use
    • not advised in pregnant women (crosses placenta)
  • DRUG INTERACTIONS
    • prolongs the metabolism of diazepam, warfarin, Dilantin
60
Q

omeprazole (prilosec): dose

A
  • 40 mg IV pre op
  • 20-80 mg PO 2-4 hours prior to surgery or the night before

PHARM ORAL 2021 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions