CLINICAL HANDBOOK OF SCHIZOPHRENIA

42. Intellectual Disability and Other Neuropsychiatric Populations 443usually proceed in a manner that is initially cautious and conservative. This is similar inprinciple to an approach one would use in geriatric psychiatry. The main point is to startwith single agents in low doses, followed by slow up-titration of dosage, with sufficienttime between dose changes to observe both positive and negative effects. We recommendbeginning with single agents and using augmentation strategies, or adding more drugsonly when monotherapy clearly has failed.We usually begin with a low dose of one of the currently available “atypical”antipsychotic drugs, advancing the daily dose in an “as tolerated” manner, depending onpositive or negative aspects of the clinical response. We normally increase the dose aboutonce a week. Measuring drug levels may be helpful if there is a question of compliance, orof suspected unusual absorption or metabolism of the drug.If a positive clinical response is absent or insufficient after about 4–5 weeks, we usuallyconsider a similar trial of another “atypical” antipsychotic. If this second trial doesnot meet clinical expectations, we might consider trying either two “atypicals” in combinationor adding a “typical” drug, such as haloperidol or perphenazine, to the most recent“atypical.” We usually pursue a particular regimen for about 1 month before changingor adding a drug.After two or three unsuccessful drug treatment trials, we consider clozapine. Somecase report data suggest that clozapine is a reasonably safe and efficacious drug for personswith ID and symptoms of schizophrenia or schizoaffective disorder (Thalayasingam,Alexander, & Singh, 2004). We also begin with a low dosage of this drug, usually 12.5mg per day. We usually cross-taper clozapine with the previous drug. One should beaware that selective serotonin reuptake inhibitors (SSRIs), especially fluvoxamine, increaseclozapine serum levels.Long-acting “depot” antipsychotic drug formulations, such as long-acting risperidone,may be considered if there is a significant compliance problem. This has seldombeen an issue in our practice, probably because most of our patients have caregivers whocan administer oral drugs.Because a straightforward diagnosis of schizophrenia is frequently not possible inpersons with more severe forms of ID, empirical treatment is sometimes necessary. Inthese more obscure situations, empirical pharmacotherapy based on a dominant symptomor symptom complex should be considered. Our experience and opinion is that themore severe, disruptive, and dangerous the behavior, the stronger the indication for empiricaldrug treatment trials. Careful analysis of likely risks and benefits is important, butit makes little sense to withhold a trial of rational pharmacotherapy in the face of persistentdangerous or severely disruptive behavior. Most modern antipsychotic drugs have favorablerisk–benefit profiles, so their careful use is ethical in these situations.Although polypharmacy should be avoided in favor of treatment with a single drugwhenever possible, complicated neuropsychiatric disorders, including schizophrenia,sometimes require use of combinations of drugs. Tracking target signs and symptoms, sothat improvement or worsening can be recognized, is an important treatment tool. Keenawareness of possible drug interactions and adverse drug effects is essential for rationaland successful pharmacotherapy. We advise and attempt to use the least number of drugsin the lowest doses necessary to achieve the desired therapeutic result.Discontinuing drugs that are causing either dangerous or distressing side effects isimportant. Also, once it is clear that a drug is ineffective, it should also be stopped, evenif there is no evident toxicity. Doing so helps to avoid creeping polypharmacy, an insidiousprocess in which individuals accrete ever-increasing numbers of unnecessary drugs.This process typically occurs when recurrent behavioral disturbances lead to new prescriptions,while the previous regimen is uncritically maintained.