Pharm: use of GI drugs

Vocabulary flashcards covering key concepts related to GI motility, vomiting mechanisms, and emetic drugs discussed in Chapters 1–6 of the lecture notes.

Segmentation (GI tract)

Rhythmic, segmental contractions that mix and move food through the GI tract; important for motility and regulated by the parasympathetic nervous system.

Hyper-mobility vs. Hypo-mobility

Increased (hyper) or decreased (hypo) GI motility; affects how quickly food moves and can influence nausea/vomiting.

Emesis (vomiting)

Forceful ejection of stomach contents; coordinated by the vomiting center in the brain and can involve diaphragmatic and stomach contractions.

Hindgut fermenters cannot vomit

Species such as rats, rabbits, and horses generally cannot vomit.

Vomiting center

Brain region that coordinates vomiting through multiple input pathways.

CRTZ (chemoreceptor trigger zone)

Brain area that detects circulating toxins and can trigger the vomiting reflex.

Endogenous emetic triggers

Internal substances that can induce vomiting (e.g., dopamine, histamine) produced within the body.

Exogenous emetic triggers

External factors that can induce vomiting (e.g., disease like uremia, toxins, medications, radiation).

Emetic pathways

Four main routes to trigger vomiting: peripheral receptors with vagus/glossopharyngeal nerves, vestibular input, higher CNS centers, and the CRTZ.

Apomorphine

Common veterinary emetic that acts on dopamine receptors in the CRTZ; given IV or as subconjunctival eye drops; controlled substance (C-II); rapid onset in dogs (3–5 minutes) but less reliable in cats.

Roparinol (Riparinol) / Klevitrin

A newer veterinary emetic used in small animals; efficacy varies by clinic; trade name Klevitrin; not universally preferred.

Hydrogen peroxide as an emetic

GI irritant used to induce vomiting; effectiveness limited and can cause GI tract irritation; typically time-limited (within ~4 hours of ingestion).

Ipecac syrup

Emetic that can cause vomiting; onset ~30 minutes; potential cardiotoxicity; not routinely recommended due to risk.

Xylazine

Alpha-2 agonist; effective emetic in cats and provides sedation; reversal possible with atipamezole (or tolazoline) if needed.

Chocolate toxicity in dogs

Toxicity depends on type; baker’s chocolate is highly toxic per ounce due to bitterness; sweeter chocolate appears less toxic per ounce in notes.

White foamy vomit

Vomitus associated with several systemic diseases (e.g., hyperthyroidism, kidney disease, liver disease, diabetes, pancreatitis, GI lymphoma); suggests non-gastric causes.

Yellow vomit (egg-yolk appearance)

Yellow, bile-containing vomit described in notes; indicates bile reflux/duodenal involvement or related GI irritation.

Megaesophagus and sausage-shaped vomit

In megaesophagus, regurgitated material may appear as a long sausage-like tube rather than a pile, indicating esophageal retention rather than true gastric vomiting.

Chronic vomiting etiologies in cats

Common causes include hyperthyroidism, inflammatory bowel disease (IBD), GI lymphoma, chronic gastritis, and other systemic diseases; cats often have distinct presentations.