Today's Veterinary Practice provides comprehensive information to keep every small animal practitioner up to date on companion animal medicine and surgery as well as practice building and management.
Issue link: http://todaysveterinarypractice.epubxp.com/i/815220
101 MAY/JUNE 2017 ■ TVPJOURNAL.COM FOCUS ON PHARMACOLOGY has been widely experimentally associated with social anxieties. If broader coverage is needed, combine it with a less specific TCA (amitriptyline, nortriptyline) and lower the dosage of both. Separation Anxiety Plus Noise Reactivity What are the concerns if the patient also reacts badly to noises? Here, we need to distinguish between panicking and being distressed ( Box 1 ). If the dog is distressed, any of the benzodiazepines may lower its reactivity level by providing central inhibition of responses. Benzodiazepines can be calming agents, antianxiety agents, or sedative and analgesic agents, depending on dose, route, and choice of medication. Alprazolam is considered the only truly "panicolytic" benzodiazepine. These compounds should not be used to treat patients in households where humans have addiction or substance abuse difficulties. Dogs that are distressed about noise or departures may respond to lorazepam and become calmer, while others may need longer-lasting benzodiazepines (diazepam, clonazepam), which may also make them sleep more. Additional and deeper sleep may not always be an adverse or sedative effect of a behavioral medication, but with long-term use benzodiazepines can disrupt natural sleep rhythms. This is not a major concern for short-term treatment. Anxious dogs likely have interrupted sleep cycles; clients often say they notice that once the dog begins to respond to medication, the dog sleeps longer or more deeply. Good, restorative sleep should be a treatment goal. In contrast, excessive sedation, including persistent cognitive impairment, lack of motor coordination, or paradoxical excitement, is an undesired effect. The key with benzodiazepines is finding the right dose for the patient; these medications have highly variable effects. Having clients test benzodiazepines for adverse events, such as excessive sedation or paradoxical excitation, when no stimulation is expected is an important step. If no adverse effects are observed, clients should then help test and record the effects of increasing dosages to see if they can find one that provides relief. Clonidine, an α2 agonist, may also aid distressed dogs by decreasing both central and peripheral signs of sympathetic arousal. At higher dosages, clonidine can be both sedative (impairing cognition) and hypotensive (rendering patients BOX 3. Sample Combinations of Medications That May Allow Dosage of Each to Be Lowered With Enhanced Efficacy 5 • Amitriptyline (TCA) [anxiety-related diagnosis] + fluoxetine (SSRI) [anxiety-related diagnosis] • Amitriptyline (TCA) [anxiety-related diagnosis] + fluoxetine (SSRI) [anxiety-related diagnosis] + alprazolam (BZD) [panic/phobia/severe distress with known trigger] • Amitriptyline (TCA) [anxiety-related diagnosis] + alprazolam (BZD) [panic/phobia] • Fluoxetine (SSRI) [anxiety-related diagnosis] + alprazolam (BZD) [panic/phobia] • Clomipramine (TCA, relatively specific) [anxiety-related diagnosis] + alprazolam (BZD) [panic/phobia] • Clomipramine (TCA, relatively specific) [anxiety-related diagnosis] + diazepam (BZD) [panic/phobia]—could be fairly sedating • Amitriptyline (TCA) [anxiety-related diagnosis] + diazepam (BZD) [panic/phobia]—could be fairly sedating • Paroxetine (SSRI) (social anxiety) + alprazolam (BZD) [panic/appetite stimulation in cats] BZD, benzodiazepine; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant.