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One drug or two-the risks and benefits of combining psychotropic medications (Proceedings)
Factors to consider before prescribing a psychoactive drug.
Factors to consider before prescribing a psychoactive drug
Does this patient need a drug?
What is the diagnosis?
What is the intensity of the behavior?
Has prior therapy been appropriately implemented?
Examine past behavioral and environmental modification steps
Selecting the primary medication
Mechanism of action
Class of medication
Type of medication
Extra-label vs FDA approved
Familiarity of prescriber with the product
Tolerance for side effects
Concurrent medical conditions & medications
Risk of side effects
Evaluating the response to single drug therapy
Effect on target behavior
If inadequate, has there been enough time for full response?
Indications for combination therapy
Slow onset chronic drug may be temporarily paired with rapid onset drug
Partial response to primary drug at adequate dose
Dosage of primary drug cannot be increased without intolerable side effects
Will the combination be safe?
Consider inhibition or potentiation of cytochrome p450 enzyme systems
Side effects may be additive
Dosage adjustments may be needed
Prepare to adjust dosages of non-psychotropic medications
Some drugs combinations are contraindicated
Eg no MAO with SSRI
Selecting adjunct medication
Diagnosis and intensity of behavior problem(s)
Age, overall health and species of patient
Side profile of primary drug
Time to therapeutic effect
Class of drug
Need extra care if two drugs are in the same family
Patient monitoring for patients on multiple drug regimen
Pretreatment baseline laboratory testing
CBC / serum chemistry profile / thyroid baseline
Reassess CBC / serum chemistry profile in one month and three months
Additional retesting every 3 – 6 months
The use of many psychotropic medications in animals may still be viewed as experimental. Extra-label use of drugs is common practice. There is little published information available regarding combination therapy. A decision to use multiple medications should be made with full client consent, and with the understanding that the potential benefit to the patient outweighs any risk.
It is rare for psychoactive drugs to be sufficient to eliminate or adequately control most behavior problems. Environmental and behavioral modification may be at least as important as the pharmacological intervention. During follow-up evaluations, confirm that clients are implementing the prescribed interventions appropriately. Offer additional treatment strategies as the patient continues to improve.