GI Flashcards
True/False:
Pharmacology of GI drugs in children esp <1 yr there is a significant knowledge gap
True
True/false:
Many GI drugs used in neonates have not been thoroughly studied.
True
In what situation are anti-emetics in neonates used?
Surgical pts
Where is vomiting controlled in the brain?
It has input from what 4 sources?
the Vomiting center of the Medulla
- Chemoreceptor trigger zone
- Cortex
- Vestibular apparatus
- GI tract
Name 2 anti-emetic agents
- Promehtazine (most common in U.S.)
s/e’s: hallucinations, sedation, seizures, HTN, tachycardia - Metoclopramide (Reglan)
s/e’s: sedation, anti-cholinergic, extrapyramidal (dyskinesia/dystonia) symptoms
There are 4 types of antacids-name them.
- Sodium Bicarbonate
- Calcium Carbonate
- Magnesium-containing
- Aluminum-containing
Chronic use of Sodium bicarbonate antacids is a/w?
Na+ retetion, systemic Alkalosis, milk-alkali syndrome
Which 2 antacid types are most potent and are rapid-acting?
Sodium Bicarbonate
Calcium Carbonate
Calcium carbonate has a longer/shorter duration of action than Sodium carbonate but is a/w what adverse side effects?
Longer
Hypercalcemia, hypercalciuria, Renal calcium deposits, compromised renal fxn, gastric acid Hyper-secretion.
Magnesium-containing antacids are a/w?
Diarrhea, Hypermagnesemia (esp w/compromised renal function)
Aluminum-containing antacids have what s/e’s?
Constipation, Hypocalcemia, & Hypophosphatemia
Concomitant use of antacids with other meds may do what?
Decrease drug absorption due to alteration in gastric pH.
When should antacids be administered?
- 2 hrs after other drugs to avoid alteration in pH and drug absorption
- 1 hr after meals
Peds pts who require long-term therapy should be monitored closely for?
Adverse effects
Prokinetic Agents do what?
Improve Gastric motility
Name 3 examples of Prokinetic Agents
- Metoclopramide (reglan)
- Cisapride
- Erythromycin
Which Prokinetic is most commonly used in the NICU?
Metoclopramide
Metoclopramide has a combination of central and peripheral __________ antagonism
Dopamine antagonism
Metoclopramide works by?
Augmentation of acetylcholine release from postganglionic nerve terminals is likely responsible for it’s effect on smooth muscle.
Does Metocloprmaide increase gastric acid secretion, endogenous gastrin release or salivation?
No
Does Metoclopramide promote the coordination of gastric, pyloric, and duodenal motor function?
Yes
How does Metocloprmaide accelerate gastric emptying?
by increasing gastric tone
True/False: Large-scale clinical trials need to be done to test the efficacy and safety of Reglan?
True, only small studies have been done.
What is significant about Cisapride?
Removed from U.S. and Canadian markets d/t safety concerns: Prolonged Q-T interval with associated V. Arrhythmias, underlying cardiac dz, electrolyte disturbances, renal insufficiency, hepatic dysfunction, and concurrent therapy with meds known to alter cardiac conduction intervals.
Is Cisapride widely available in other parts of the world?
Yes
Erythromycin is thought to increase what ?
Lower esophageal sphincter tone in the duration but not amplitude of contractions of the distal esophagus in adults with GER
The dose of Erythromycin is Larger/Smaller than the dose for antimicrobial therapy?
Smaller
The effect of EES is similar to the polypeptide hormone ________ (promoting movement of nutrients)
Motilin
The association with Erythromycin and what condition is a concern?
Hypertrophic Pyloric Stenosis
When was the association of Erythromycin with pyloric stenosis discovered?
After wide-spread use of Erythromycin for Pertussis outbreak in a community–>7x increased rate of pyloric stenosis
Is low-dose Erythromycin a/w pyloric stenosis?
No
H-2 receptor antagonists are the most commonly used drugs in children for?
- Reflux
- Treatment of gastric/duodenal ulcers
- Treatment/prophylaxis against GI hemorrhage
There are how many H-2 receptor antagonists available for clinical use?
How many for children?
What are they?
4
2
Ranitidine & Famotidine
H-2 Receptor Antagonists reduce?
Gastric acid secretion by inhibiting Histamine at the H2 receptor site.
H-2 Receptor Antagonists decrease?
Acid-secretory response of parietal cells
H-2 Receptor Antagonists are particulary effective in suppressing…?
Nocturnal acid production
esp important in those at risk for Duodenal ulcers
True/False: H-2 Receptor Antagonists are frequently used in NICU as prophylaxis for gastric stress ulcers
True
Routine use of H-2 Receptor Antagonists has lead to what concerns?
Alteration of gastric pH
may allow for over-growth of pathogenic bacteria and in LWB’s–NEC
What are the s/e’s of H-2 Receptor Antagonists?
Most common:GI symptoms, Rash, Dizziness
Also: Mania, seizures, gynecomastia, galactorrhea, impotence, possible decrease in spermatogenesis, thrombocytopenia, agranulocytosis
True/FalseProton-Pump Inhibitors are the most common GI medication used in the NICU?
True
Which PPI is the most commonly used?
Prevacid (Lansoprazole)
There are how many approved PPI’s in the U.S.?
Do any have approved labeling for children <1 y/o?
4
No
What is Prevacid (Lansoprazole) used for?
Tx of reflux esophagitis
Inhibits gastric acid secretion (inhibits H+/K+/ATPase–enzyme responsible for production of HCl- by parietal cells of proton pump)
Where is Prevacid metabolized?
Liver
Onset of action of Prevacid is w/in?
Max effect w/in?
Average T2?
1 hr
- 5 hrs
- 5 hrs
Inhibition of Acid secretion is about ___% of maximum at 24 hrs of age with duration of action about ___ hrs.
50%
72 hours
What are the most common s/e’s of Prevacid?
Headache, Nausea, Diarrhea
True/False: there is questionable a/w VLBW and late-onset gram negative sepsis
True
