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antipsychotic. Of these patients, 4 had full orpartial remission, and 1 was lost to follow up.Another case series compared 4 patientstreated with risperidone and onetreated with quetiapine. 27 Three of the 4risperidone-treated patients experiencedtotal resolution of delusions; one of thesethree patients was also on lithium, anotherwas on sertraline and alprazolam as well,and another was also on sertraline anddonepezil. The last risperidone treatedpatient had a decrease in delusions and wason no other medications. The patient treatedwith quetiapine showed partial remissionand was also on venlafaxine, clonazepam,buspirone and bupropion.Shah and Pervez (2009) published onlythe second case report for the use ofrisperidone long-acting injections (RLAI). 29The patient refused to take oral risperidone,but accepted RLAI 25 mg IM every 2 weeks.This dosage was titrated up to 37.5 mg IMon discharge and she then switched to 5mg/day PO risperidone. Her symptomsimproved, although complete remission wasnot achieved.There are also newer atypical antipsychoticswhose efficacy in the treatment of DPhas only been documented in a limitednumber of case studies. One example isaripiprazole. 30-32 Rocha and Hara (2007)documented the first case of aripiprazoletreatment in an 85 year old DP patientand she underwent full remission. 30 Ina subsequent study, 2 patients with DPwere treated with aripiprazole and bothhad complete remission. 31 Paliperidone, anatypical antipsychotic approved by the FDAin 2006, has only been used in one DP case,where an 88 year old man treated with thedrug underwent complete remission. 33DISCUSSIONOur review of typical antipsychoticsindicates that pimozide is an effectivetreatment option for DP. The rates of fullor partial remission were similar to thenumbers reported in a systematic review byLepping et al. (2007). 10 There have been anumber of smaller case reports and studiesutilizing other typical antipsychotics such ashaloperidol, trifluoperazine, flupenthixol andfluphenazine depot, all of which showedexcellent rates of full or partial remission. 10Despite the past successes of pimozide, it isno longer considered first-line treatment ofDP, due to the advent of the safer atypicalantipsychotics. 34Furthermore, the long-term use of pimozideis associated with a number of adverseside effects. Extrapyramidal symptomssuch as tardive dyskinesia, parkinsonismand akathisia occur in less than 10-15%of patients treated with pimozide forschizophrenia, and Gilles de la TouretteSyndrome. 11 It has also been associatedwith clinically significant QT cintervalprolongation, including Torsades de Pointes,possibly due to the calcium channelblocking effects of the drug. 7, 14, 35 These sideeffects, especially its cardiac effects anddrug interactions (drugs metabolized bycytochrome P450 isoenzyme 3A4), makepimozide a non-ideal DP therapy. 34Much less is known about atypicalantipsychotics, because of their relativelyrecent introduction compared to typicalantipsychotics. The largest review to dateof atypical antipsychotic use in DP wasconducted in 2008 by Freudenmann andLepping, 34 which concluded that atypicalantipsychotics should be the first linetherapy for DP.The atypical antipsychotics with the largestsample sizes in our review were risperidoneand olanzapine. Risperidone has beenestablished as the most common atypicalantipsychotic used in the treatment of DP.The particular effectiveness of this drug hasbeen linked to its high affinity for 5-HT 2receptors, a receptor which has been linkedto psychotic processes and perceptualdifferences. 12 Although risperidone’sside effect profile is superior to that oftypical antipsychotics, there are instanceswhere parkinsonism and akathisia havebeen produced by its use and it has beenassociated with a mild increase in metabolicsyndrome. 32 An added benefit of risperidoneis that it is the only atypical antipsychoticavailable as a long-acting depot. Long actinginjections are particularly useful in patientswho are demonstrating harmful behavioursand refusing to comply with oral treatment.The goal of such a treatment would beto help the patient accept their problemis psychological and thus comply withoral therapy.Olanzapine is the second most commonatypical antipsychotic used in DPtreatment. 34 Its side effect profile is alsosuperior to that of pimozide and it rarelycauses extrapyramidal syndrome. However,this medication is closely associated withmetabolic syndrome and sedation. 32 Its useis still limited by a smaller body of evidence,but the fact that three patients treated withrisperidone were switched to olanzapinedue to intolerance suggests it may be a moretolerable drug. 25Quetiapine had an excellent remission rate,but with a small sample size (n=2), morestudies must be done in order to assess itsuse in the treatment of DP. Freudenmannand Lepping (2008) found a full or partialremission rate of 88% after reviewing 8cases. 34 The side effect profile of quetiapineis generally limited to drowsiness, dizzinessand postural hypotension, with minimalrisk of extrapyramidal symptoms or adversecardiac effects. 36 Quetiapine’s excellentside effect profile combined with its highremission rate makes it a potential treatmentfor DP.The results of aripiprazole treatment in DPhave only been published for 4 patients todate with all 4 demonstrating full or partialremission. 23-25 There have not been anyrandomized control trials or placebo crossover studies performed with aripiprazoleand DP, but the case study results arepromising. Adverse effects of aripiprazoleinclude nausea and akathisia, but it is nonsedatingand less often associated withextrapyramidal symptoms and metabolicdisturbances. 37 This excellent side effectprofile may make it beneficial to DP patientswho cannot tolerate the side effects ofother antipsychotics.Paliperidone is the latest atypicalantipsychotic used in the treatment of DP.Paliperidone is the main active metaboliteof risperidone and it blocks 5-HT 2Aand D 2-receptors. It has a long half-life of 24 hours,which decreases the number of daily doses.As well, it decreases the risk of any potentialadverse drug reactions, which is especiallyimportant because many DP patients havenumerous co-morbidities being treatedsimultaneously. 33 The clinical efficacy ofpaliperidone as a treatment for DP needsto be confirmed by further case studies orrandomized control trials.CLINICAL IMPLICATIONSDiagnosis of DP is definitely within thescope of a dermatology practice. However,the psychological basis of the disordermakes initiating therapy in a dermatologistoffice challenging. Patients often feel asif their symptoms are not being seriouslyconsidered when the dermatologist triesto explain that the disease is psychotic innature. Referral to a psychiatrist is oftenmet with anger and frustration, resultingin the patient either seeking the opinionof another dermatologist or resorting toself-treatment, which may be potentiallyharmful. 10 It may be prudent to ask thepatient’s thoughts on you consulting anexpert colleague who deals with similarconditions more frequently. This will openthe door to discussing the managementplan with a psychiatrist, while empoweringthe patient to be actively involved in thetreatment decision.REVIEWUniversity of Alberta Health Sciences Journal • April 2012 • Volume 7 • Issue 1 11