Medication antiparkinsonian

A summary of available antiparkinsonian medications is listed in Table 55-2. 

Six patients with Parkinson s disease were withdrawn from their antiparkinsonian medications (L-DOPA/carbidopa, bromocriptine, or lisuride) (Rabey et al. 1992, 1993). After 12 hours off medication, the subjects ate 250 g of cooked fava beans. Significant improvements in motor symptoms were noted, comparable to those seen with 125 mg of L-DOPA and 12.5 mg of carbidopa. In fact, three subjects developed severe dyskinesias after fava ingestion, akin to those seen after larger doses of pharmaceutical L-DOPA. Plasma levels of L-DOPA increased after fava ingestion in a manner comparable to that seen with administration of oral L-DOPA. These results suggest that the L-DOPA contained in fava beans was transported into the CNS and converted to dopamine. In five nonparkinsonian, healthy volunteers, a similar increase in plasma L-DOPA was observed after fava ingestion, although much lower. The difference in plasma L-DOPA between normal volunteers and parkinsonian patients is apparently due to a residual effect of carbidopa in the subjects with Parkinson s disease. Without carbidopa, the L-DOPA from fava is rapidly converted to dopamine in the blood stream and never crosses the blood-brain barrier. 

Addition of other antiparkinsonian medications Standard drugs for Parkinson disease may be used concomitantly while carbidopa, levodopa, and entacapone... 

Kissling et al. (27,9) evaluated both fluphenazine and haloperidol decanoate in a 6-month double-blind study involving 31 schizophrenic patients. These authors found both were equally effective in preventing relapse, with a slight advantage for haloperidol decanoate as reflected by fewer adverse effect-related dropouts and a decreased need for antiparkinsonian medications with this latter agent. Wistedt ( 280) compared fluphenazine decanoate with haloperidol decanoate in a double-blind... 

Prophylactic antiparkinsonian medication for all patients on antipsychotics is controversial. Arguments against this approach include ... 

Studies in which antiparkinsonian medications were discontinued have significant methodological problems. One specific issue is that patients placed on prophylactic therapy, who then fail to develop symptoms when their antiparkinsonian medication is withdrawn, may never have developed EPS at all. Still, up to 70% of patients have been noted to exhibit EPS after discontinuation of their antiparkinsonian drug, indicating that these agents indeed provide long-term efficacy. 

Comaty et al. (452) conducted a prospective double-blind, placebo-controlled trial of low-dose benztropine (i.e., 2 mg/day) maintenance therapy. After an acute EPS had been stabilized with 2 days of active antiparkinsonian medication, the recurrence of EPS did not differ significantly between those maintained on active drug or those switched to placebo over the next 8 days. While there was a trend favoring the active drug group, low-dose maintenance benztropine (i.e., 2 mg/day) afforded little benefit in comparison with placebo. 

Preclinical and clinical data indicate that olanzapine may have antipsychotic effects at doses below its EPS threshold. Although early clinical results substantiated a lesser propensity to cause EPS at the low end of the dose-response curve, with dose escalation there was a concomitant increase in the use of antiparkinsonian medication (473). In this context, it should be noted that studies that used higher olanzapine doses found them to be more effective than low to intermediate doses (117). Thus, olanzapine may be similar to risperidone in that both drugs have a therapeutic dose range in which the antipsychotic effect can be achieved without inducing significant EPS. 

Preclinical studies of ziprasidone indicate that it also has a low propensity to induce EPS, which was confirmed in subsequent phase II and III studies. Furthermore, the motor symptoms evoked by ziprasidone were seldom sufficiently troublesome to warrant anticholinergic medication. In one phase III trial, not more than 25% of patients receiving 160 mg/day were prescribed an anticholinergic at any time during the 6-week treatment period. These results indicate that therapeutic doses of ziprasidone not only induce a low incidence of acute EPS, but when they occur, they are often mild and do not require antiparkinsonian medication (137). 

Physostigmine, given intravenously, counteracts both the peripheral and central side effects of atropine and other anticholinergic drugs such as thioridazine (neuroleptic), imipramine (antidepressant), and benztropine (antiparkinsonian medication). 

In a retrospective study, a substantial proportion of patients who needed antiparkinsonian medication while taking risperidone (mean daily dose 4.4 mg) were identified. Twelve of fifty-five elderly inpatients (aged over 65 years) taking risperidone received antiparkinsonian drugs (216). 

Improvement in the primary outcome measure, the UPDRS Motor score in the practically defined OFF state (off all antiparkinsonian medication for at least 12 hours), was observed in all patients at 12 months and persisted until month 24. 

Interaction with over-the-counter cold and allergy preparations, antihistamines, amphetamines, insulin, narcotics, and antiparkinsonian medications... 

Medications are often prescribed to decrease or control movement-related side effects and are referred to as anti-parkinsonian medications. When a client is receiving a traditional or typical antipsychotic medicine it is essential to determine if something has been prescribed to counter the side effects that might result. The medications that are often used to address the side-effect profiles just described are listed. (See list that follows for typical antipsychotic and antiparkinsonian medications.)... 

Nervous system Serotonin syndrome with rhabdomyolysis occurred in a patient with Parkinson s disease after he had taken venlafaxine 75 mg/day for depression for 2 weeks [23" ]. Previous reports of serotonin syndrome with venlafaxine have been related to overdose [24 ]. Parkinsonism or drug-drug interactions with the antiparkinsonian medications may have predisposed this patient to serotonin syndrome at such low doses of venlafaxine. 

Associated problems, such as increases in glucose and cholesterol, were usually also more frequent with olanzapine. Nevertheless, olanzapine may be associated with more extrapyramidal reactions than quetiapine, as judged by use of antiparkinsonian medications (RR=2.05 95%... 

A 6-week randomised, single-blind study compared risperidone plus divalproate and haloperidol plus divalproate in the treatment of mania [16 ]. There were significantly more extrapyramidal side effects and dyskinesia as well as more antiparkinsonian medication use with haloperidol. Mean weight increase and proportion of patients with clinically relevant weight gain (>7%) were greater with risperidone. 

A study is reported of the sudden withdrawal of antiparkinsonian medication in a group of chronic mental hospital in-patients who were receiving a variety of major tranquillizers. Of the 32 patients who had completed the study at the time of the report, none had required urgent renewal of antiparkinsonian medication and only 4 had shown a return of symptoms which were thought to justify further medication within 3 weeks of drug withdrawal. Subsequent follow-up of the patients for a minimum of 133 days revealed no further patients requiring antiparkinsonian medication (30 ). 

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