drug-interaction-checker

# Veterinary Drug Interaction Checker ## Overview Evaluate potential drug-drug interactions in veterinary patients. Drug interactions in animals differ from humans due to species-specific differences in hepatic metabolism (cytochrome P450 enzyme profiles), protein binding, renal clearance, and GI physiology. This skill checks for known interactions and flags combinations requiring dose adjustment or monitoring. ## When to Use - User asks whether two or more drugs can be given together to an animal - User is adding a new medication to an existing regimen - User asks about drug interactions in a specific species - Keywords: interaction, combine, together, concurrent, polypharmacy, concomitant, contraindicated combination ## Workflow 1. Identify all drugs in the patient's regimen (including supplements, nutraceuticals). 2. Confirm species (MANDATORY - metabolism pathways differ). 3. Check each drug pair for known interactions: - **Pharmacokinetic interactions:** Enzyme induction/inhibition, protein binding displacement, altered absorption - **Pharmacodynamic interactions:** Additive effects, synergism, antagonism 4. Classify severity: - **Contraindicated:** Must not be used together (e.g., MAOIs + serotonergic drugs) - **Major:** Significant risk requiring alternative therapy or intensive monitoring - **Moderate:** May require dose adjustment or monitoring - **Minor:** Minimal clinical significance but document 5. Provide management recommendation for each interaction found. ## Common Veterinary Drug Interactions - **NSAIDs + corticosteroids:** Increased GI ulceration risk (especially in dogs) - **ACE inhibitors + potassium-sparing diuretics:** Hyperkalemia risk - **Phenobarbital + many drugs:** CYP450 enzyme inducer; decreases levels of concurrent drugs - **Ketoconazole/itraconazole + many drugs:** CYP450 inhibitor; increases levels of concurrent drugs - **Metoclopramide + opioids:** Antagonistic effects on GI motility - **Fluoroquinolones + divalent cations (sucralfate, antacids):** Chelation reduces absorption - **Cisapride + azole antifungals:** QT prolongation risk - **Selegiline (Anipryl) + serotonergic drugs (tramadol, SSRIs, TCAs):** Serotonin syndrome risk. Selegiline is an MAO-B inhibitor used for canine cognitive dysfunction. Do not combine with tramadol, fluoxetine, clomipramine, or amitriptyline. Allow 2-week washout between discontinuation and starting a serotonergic drug. - **Metronidazole + phenobarbital:** Phenobarbital induces metronidazole metabolism; may require dose adjustment - **Cyclosporine + ketoconazole:** Ketoconazole intentionally used to reduce cyclosporine dose (cost-saving strategy in vet practice, but requires monitoring) ## Output Format ``` ## Drug Interaction Check: [Species] **Medications:** [List all drugs] **Interactions found:** 1. [Drug A] + [Drug B] - **Severity:** [Contraindicated/Major/Moderate/Minor] - **Mechanism:** [How they interact] - **Clinical effect:** [What could happen] - **Management:** [What to do about it] **No interactions found between:** [List non-interacting pairs] ``` ## Limitations - Veterinary drug interaction databases are less comprehensive than human databases. Many interactions are extrapolated from human data. - Individual patient factors (hepatic/renal disease, age) affect interaction risk. - Nutraceuticals and supplements may have undocumented interactions. - This skill identifies known interactions; absence of a listed interaction does not guarantee safety.