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99 MAY/JUNE 2017 ■ TVPJOURNAL.COM FOCUS ON PHARMACOLOGY Most of these medications are metabolized through the cytochrome P-450 system. Table 3 lists inducers and inhibitors that affect how these behavioral compounds are metabolized. Understanding such P-450 enzyme system interactions allows medication adjustment to minimize adverse events. Although most available information is for humans, some studies have measured CYP effects for dogs, 11–14 with particularly strong conservation for CYP 1A enzymes. Isoforms are sufficiently similar between humans and dogs that inference from human information may serve as a good precaution. TAILORING THERAPY: CLINICAL EXAMPLES Applying an approach that seeks to tailor treatment in behavioral medicine to specific presentations and targeted signs is not difficult but does require thought. Separation Anxiety A dog with separation anxiety that involves salivation will benefit from any anticholinergic agent because the undesirable effect may be part of a reinforcing feedback cycle. Medications classified as anticholinergics are not used in TABLE 1 Relative Effects of Medications on Noradrenaline/Norepinephrine and Serotonin Receptors and for Sedation or Anticholinergic Effects 8–10 PARENT COMPOUND NA/NE 5-HT POTENTIAL FOR SEDATION POTENTIAL FOR ANTICHOLINERGIC EFFECTS TCAs Imipramine +++ ++ Moderate Moderate Amitriptyline ++ ++ High High Nortriptyline + + Moderate Moderate Clomipramine ++ +++ High High SSRIs Fluoxetine + +++ Moderate Low Paroxetine ++ High High Sertraline + +++ Moderate Moderate Fluvoxamine +++ Moderate Citalopram +++ Moderate Moderate SARIs Trazodone ++ High Low Benzodiazepines Alpraz olam Low to moderate Lorazepam Low to moderate Diazepam High Clonazepam Moderate α-Agonists Clonidine Moderate OTM dexmedetomidine Low +, some effect; ++, moderate effect; +++, large effect; 5HT, 5-hydroxytryptamine (serotonin); NA/NE, noradrenaline/norepinephrine; OTM, oral transmucosal; SARI, serotonin antagonist/reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant.