An updated calculator for determining levodopa-equivalent dose.

Calculation of levodopa-equivalent dose in Parkinson's disease has become common in research, but is also a useful tool in clinical practice, especially when initiating device-aided treatments (deep brain stimulation, apomorphine and levodopa infusions). The aim with the present calculator is to provide an updated conversion table, including dose calculation of the recently developed levodopa/entacapone/carbidopa intestinal gel infusion. Future versions of the calculator should be made conducive to learning by means of artificial intelligence.

Population pharmacokinetics of levodopa gel infusion in Parkinson's disease: effects of entacapone infusion and genetic polymorphism.

Levodopa-entacapone-carbidopa intestinal gel (LECIG) provides continuous drug delivery through intrajejunal infusion. The aim of this study was to characterize the population pharmacokinetics of levodopa following LECIG and levodopa-carbidopa intestinal gel (LCIG) infusion to investigate suitable translation of dose from LCIG to LECIG treatment, and the impact of common variations in the dopa-decarboxylase (DDC) and catechol-O-methyltransferase (COMT) genes on levodopa pharmacokinetics. A non-linear mixed-effects model of levodopa pharmacokinetics was developed using plasma concentration data from a double-blind, cross-over study of LCIG compared with LECIG in patients with advanced Parkinson's disease (n = 11). All patients were genotyped for rs4680 (polymorphism of the COMT gene), rs921451 and rs3837091 (polymorphisms of the DDC gene). The final model was a one compartment model with a high fixed absorption rate constant, and a first order elimination, with estimated apparent clearances (CL/F), of 27.9 L/h/70 kg for LCIG versus 17.5 L/h/70 kg for LECIG, and apparent volume of distribution of 74.4 L/70 kg. Our results thus suggest that the continuous maintenance dose of LECIG, on a population level, should be decreased by approximately 35%, to achieve similar drug exposure as with LCIG. An effect from entacapone was identified on all individuals, regardless of COMT rs4680 genotype. The individuals with higher DDC and COMT enzyme activity showed tendencies towards higher levodopa CL/F. The simultaneous administration of entacapone to LCIG administration results in a 36.5% lower apparent levodopa clearance, and there is a need for lower continuous maintenance doses, regardless of patients' COMT genotype.

Workforce participation and activities in Parkinson's disease patients receiving device-aided therapy.

OBJECTIVES: Many countries have an aging population, and it is thus likely that Parkinson's disease (PD) will become an increasing health problem. It is important to ensure this group can use their resources in the best way possible, including remaining in the work market. This study aimed to investigate workforce participation and daily activities among patients with PD receiving device-aided therapy to provide new knowledge that may be used to inform decisions about these therapy options. MATERIALS AND METHODS: This was a retrospective, descriptive quantitative pilot study, including 67 patients with PD from 3 centers in Sweden and Denmark. Included patients were younger than 67 years at the time of introduction of device-aided therapy. Eligible patients were identified by the Swedish national Parkinson patient registry or by the treating neurologist. Quantitative interviews were made by telephone. RESULTS: A majority of the patients could perform the same, or more, amount of activities approximately 5 years after the introduction of device-aided therapy. A small number of patients receiving deep brain stimulation (DBS) and levodopa-carbidopa intestinal gel (LCIG) were able to increase their work capacity within 1 year of initiating device-aided therapy and a remarkably high share could still work at the end-point of this study, approximately 15 years since the diagnosis of PD. CONCLUSIONS: Device-aided therapy may sustain or increase daily activities and workforce participation in patients with PD who have not yet reached retirement age. There is need for prospective studies, both quantitative and qualitative, to confirm these results.

First clinical experience with levodopa/carbidopa microtablets in Parkinson's disease.

BACKGROUND: Levodopa is the most effective symptomatic treatment throughout the course of Parkinson's disease, but as the disease progresses, there may be a need for individualized, fine-tuned treatments. AIM: To evaluate individualized levodopa/carbidopa dosing using microtablets dispensed with a dose dispenser, with respect to efficacy and usability as perceived by patients. METHODS: Patient records and dose dispenser reports from patients previously or currently treated with microtablets and a dose dispenser were reviewed, and a patient questionnaire concerning effect and usability was sent to patients. RESULTS: Eleven patient records, four dose dispenser reports and nine survey responses were obtained. The treatment effect was considered to be improved by six of nine patients. One-third found their bradykinesia to be improved, and the non-troublesome dyskinesia was unchanged according to a majority of patients; however, some experienced the duration and magnitude of troublesome dyskinesia to be worse. The usability was generally rated as good. The four dose dispenser reports obtained showed 97(±5)% total adherence. CONCLUSIONS: The experienced effect of treatment can, for some patients, be improved by the use of microtablets, and the dose dispenser was considered user-friendly. Further studies with a larger study population and prospective design are needed to confirm the results.

Transcutaneous port for levodopa/carbidopa intestinal gel administration in Parkinson's disease.

OBJECTIVE: To evaluate the safety and tolerability of the T-Port(®) for intestinal infusion of levodopa/carbidopa gel in patients with advanced Parkinson's disease (PD). METHODS: This prospective study was carried out in 24 patients with PD (15 males, mean age 61.8 years, mean duration PD 18.7 years). All adverse device effects were evaluated at 2 weeks, 3 months and 6 months and until explantation or death. RESULTS: Post-operative complications were similar to endoscopic gastrojejunostomy placement (four peritoneal irritation, one pocket pain). Eight patients with prior experience with the endoscopic gastrojejunostomy preferred the T-Port. The total device experience was 83.6 years, and the average survival time was 3.6 (range 1.1-5.2) years. Six T-Ports were still in use, and two patients had died due to non-device-related reasons. Sixteen T-Ports had been explanted due to 15 stoma reactions (14 inflammations and one infection) and one tilting of the T-Port. The T-Ports were replaced with endoscopic gastrojejunostomy system as replacements with T-Ports were not part of the study. Only two device malfunctions occurred (one catheter breakage at 3 year post-implant and one T-Port leakage of levodopa/carbidopa gel). No tube kinking, dislocation or blockage occurred. The number of adverse device effects proved to be significantly lower as compared to the endoscopic gastrojejunostomy literature data. CONCLUSIONS: The T-Port is safe and well tolerated, and the low number of tube problems is a potential advantage compared with the endoscopic gastrojejunostomy system. Proper cleaning and local treatment of the stoma site around the T-Port are essential to prolong its longevity.

Frequent administration of levodopa/carbidopa microtablets vs levodopa/carbidopa/entacapone in healthy volunteers.

OBJECTIVES: An oral dispersible microtablet formulation of levodopa/carbidopa 5/1.25 mg (LC-5) was developed for individualized repeated dosing. The aim was to compare pharmacokinetic profiles of LC-5 and levodopa/carbidopa/entacapone (LCE). MATERIALS AND METHODS: A randomized, crossover study was carried out in 11 healthy subjects. Plasma concentrations of levodopa, carbidopa and 3-O-methyldopa were determined after intake of 300 mg levodopa during the day, either as three intakes of 100/25/200 mg LCE or as a morning dose of 75/18.25 mg followed by five repeated doses of 45/11.25 mg LC-5. RESULTS: Repeated dosing (2.4-hourly) with LC-5 microtablets compared to LCE (6-hourly) avoided long periods with low plasma levodopa levels. Time to maximum plasma concentrations was significantly shorter for LC-5. LC-5 showed lower fluctuation index (FI) in plasma compared to LCE (ANOVA P = 0.0028). FI for dose 2-5 was on average 1.26 for levodopa in LC-5, and 2.23 for dose 1-2 of LCE. The ratio between the two mean FI:s is 0.565; that is, LC-5 gave nearly half the FI as compared to LCE. CONCLUSIONS: Fractionation of levodopa with LC-5 into small, frequent administrations as compared to standard administrations of LCE decreased the FI in plasma for both levodopa and carbidopa by nearly half.

Interim analysis of long-term intraduodenal levodopa infusion in advanced Parkinson disease.

BACKGROUND: This interim 12-month analysis is a part of an open-label, observational, prospective study on health outcomes and cost impact of levodopa/carbidopa intestinal gel (LCIG, Duodopa) in Parkinson disease (PD). The specific aim was to investigate clinical and health-related quality of life (HRQoL) effects in routine care. METHODS: Unified PD rating scale (UPDRS) was the primary efficacy measurement. PD QoL questionnaire 39 (PDQ-39) assessed HRQoL. Subjects were assessed at baseline, ≥3 months after surgery, and then every 3 months. RESULTS: Twenty-seven treatment-naïve subjects when started with LCIG showed a decrease in UPDRS score that was statistically significant throughout the year: UPDRS total score (mean ± SD), baseline = 52.1 ± 16.1, N = 27, month 0 (first visit; at least 3 months after permanent LCIG) = 43.1 ± 16.7, N = 27, P = 0.003; month 12 = 42.5 ± 22.6, n = 25, P = 0.017. PDQ-39 results also showed a tendency for improvement: PDQ-39 (mean ± SD), baseline = 33.6 ± 10.8, N = 27, month 0 = 27.1 ± 11.8, N = 27, P = 0.001; 12 months = 28.8 ± 12.8, n = 23, P = 0.126. CONCLUSIONS: LCIG provides functional improvement beginning at first visit that is sustained for 12 months.

Levodopa/carbidopa intestinal gel infusion long-term therapy in advanced Parkinson's disease.

BACKGROUND: Infusion of levodopa/carbidopa intestinal gel (Duodopa ; Abbott) was introduced in Sweden in 1991 as an experimental treatment in advanced Parkinson's disease and obtained EU approval in 2004. There is compelling evidence for short-term use of this treatment; however, long-term data are scarce. METHODS: A retrospective review of medical records was performed. The primary objective was to assess the duration of treatment for all Swedish patients starting long-term levodopa/carbidopa gel therapy between January 1991 and June 2008. Secondary aims were to study demographics, treatment with anti-Parkinson's disease drugs and other concomitant medications, and reasons for discontinuation of levodopa/carbidopa gel. RESULTS: Of 150 identified patients, 135 were included in the study. On average, patients were 49 years at diagnosis of Parkinson's disease and 63 years when infusion therapy was initiated. The median treatment time on infusion was 3.4 years (range, 0-16 years). The restricted mean treatment time was nearly 8 years; 81 patients were still on treatment at the end of the study. Levodopa was used as monotherapy in a majority of patients. Dosage of the drug was stable over time. Thirty-one patients discontinued infusion prior to the cutoff date and 23 patients died. Device-related problems were the most common reason for discontinuation. Patients were more likely to discontinue infusion therapy before 2000. The year of infusion initiation was significantly earlier in the dropout group compared with a matched group of continuing patients. CONCLUSIONS: Levodopa/carbidopa intestinal gel infusion is a long-term treatment alternative in patients with advanced Parkinson's disease.

Levodopa infusion combined with entacapone or tolcapone in Parkinson disease: a pilot trial.

BACKGROUND AND PURPOSE: Catechol-O-methyltransferase inhibitors may be used to decrease levodopa requirement. The objective was to investigate whether the levodopa/carbidopa intestinal gel infusion dose can be reduced by 20% without worsening of motor fluctuations and levodopa concentration stability when oral catechol-O-methyltransferase inhibitors are added. METHODS: A short-term, randomized, partly blinded, crossover, investigator-initiated clinical trial was performed, with levodopa/carbidopa intestinal gel combined with oral entacapone and tolcapone on two different days in 10 patients. The primary outcome measure was difference in coefficient of variation of levodopa in plasma between levodopa/carbidopa, levodopa/carbidopa/entacapone, and levodopa/carbidopa/tolcapone. The secondary outcome measures other pharmacokinetic variables, patient-reported outcome, and blinded analysis of motor performance. RESULTS: Variation of plasma levodopa concentrations did not differ significantly between the treatments. The treatments did not differ regarding motor performance. Levodopa concentrations were significantly higher using tolcapone. Concentrations of the metabolite 3-O-methyldopa decreased gradually during catechol-O-methyltransferase inhibition. CONCLUSIONS: According to this small, short-term pilot study, oral catechol-O-methyltransferase inhibitors administered in 5-h intervals may be useful in cases where levodopa/carbidopa intestinal gel dose reduction is wanted. Stability of plasma levodopa levels is not significantly altered, and off-time is not increased when decreasing the levodopa/carbidopa intestinal gel dose by 20%. Rather, the dose should probably be decreased more than 20%, especially under tolcapone co-treatment, to avoid increased dyskinesias with time.

Large differences in levodopa dose requirement in Parkinson's disease: men use higher doses than women.

BACKGROUND AND PURPOSE: The characteristics of levodopa dosing are not well described in the literature. The aims were to investigate the use of levodopa in a nationwide Swedish survey and to study the characteristics of low-dose and high-dose patients with Parkinson's disease (PD) in a university hospital. METHODS: Patients with >or= 1 and >or= 2 purchases of levodopa during 2007 were selected from the prescribed drug register. Daily levodopa doses were estimated. Records of 504 patients with PD who visited the neurology clinic at Uppsala University Hospital during 2006-2007 were examined to select a low-dose group (< or = 400 mg levodopa daily, n = 21) and a high-dose group (>or= 1200 mg daily, n = 26) with at least 5 years of PD duration. RESULTS: In total, 33 534 levodopa users with > or = 1 levodopa purchase were found. Daily levodopa dose range was large; median daily dose was 465 mg for men and 395 mg for women (P < 0.0001). Almost half (46%) of the patients used < 400 mg levodopa daily. Significantly, more men were treated with doses >or= 1200 mg daily. Dose and age correlated negatively (P < 0.0001). Patients with high dose at 5 years PD duration continuously increased their dosage the following years, whereas low-dose patients did not. The occurrence of dyskinesias was about the same in both groups despite the large difference in levodopa dose. CONCLUSIONS: We conclude that the levodopa requirement in PD ranges considerably, and that men use higher levodopa dose than women. Levodopa requirement is constant during the progression of the disease in low-dose patients but increases in high-dose patients.

Clinical, neuroimaging and neurophysiological features in addicts with manganese-ephedrone exposure.

OBJECTIVE: To identify biomarkers supporting the clinical diagnosis of manganism in patients several years after exposure to manganese (Mn). METHODS: Neurophysiological examinations, magnetic resonance imaging (MRI), single-photon emission computed tomography and fluorodeoxyglycose (FDG) positron emission tomography were performed in four former ephedrone addicts with extrapyramidal symptoms. RESULTS: Peripheral nervous system was not affected. No patients had reduced uptake of (123)I Ioflupane in the striatum. MRI signal intensities were slightly changed in the basal ganglia. All patients showed a widespread, but not uniform, pathological pattern of FDG uptake with changes mainly located to the central part of the brain including the basal ganglia and the surrounding white matter. CONCLUSIONS: Presynaptic neurons in the nigrostriatal pathway are intact in Mn-induced parkinsonism after prolonged abstinence from ephedrone. The diagnosis is principally based on clinical signs and the history of drug abuse.

Comparison of apomorphine and levodopa infusions in four patients with Parkinson's disease with symptom fluctuations.

BACKGROUND: Motor fluctuations in patients with advanced Parkinson's disease may be successfully treated with subcutaneous apomorphine infusion or intraduodenal levodopa/carbidopa infusion. No comparative trials of these two alternatives were performed. AIMS OF THE STUDY: We present a subanalysis from a randomized crossover clinical trial where levodopa infusion as monotherapy was compared with any other combination of pharmacotherapy in fluctuating patients. Four patients used apomorphine infusion and oral levodopa in the comparator arm. The results of these four patients are presented in detail. METHODS: The duration of the trial was 3 + 3 weeks. Patients were video-recorded half-hourly on two non-consecutive days of both treatment arms. Blinded video ratings were used. Patient self-assessments of motor function and quality-of-life (QoL) parameters were captured using an electronic diary. RESULTS: Ratings in moderate to severe "off" state ranged 0-44% on apomorphine infusion and 0-6% on levodopa infusion. Moderate to severe dyskinesias were not recorded in any of the treatments. QoL was reported to be improved in all patients on duodenal levodopa infusion. CONCLUSIONS: Monotherapy with duodenal infusion of levodopa was more efficacious and brought greater QoL than combination therapy with apomorphine infusion in these fluctuating patients.

Fluctuating functions related to quality of life in advanced Parkinson disease: effects of duodenal levodopa infusion.

OBJECTIVE: To assess fluctuations in quality of life (QoL) and motor performance in patients with advanced Parkinson disease (PD) treated with continuous daytime duodenal levodopa/carbidopa infusion or conventional therapy. METHODS: Of 18 patients completing a 6-week trial (DIREQT), 12 were followed for up to 6 months and assessed using electronic diaries and the PD Questionnaire-39 (PDQ-39). RESULTS: During the trial and follow-up, major diurnal fluctuations were observed, especially for hyperkinesia, 'off' time, ability to walk and depression. Duodenal infusion was associated with significantly more favourable outcomes compared with conventional treatment for satisfaction with overall functioning, 'off' time and ability to walk, with improved outcomes with PDQ-39. CONCLUSIONS: Relative to conventional treatment, infusion therapy may stabilize and significantly improve motor function and patient's QoL. The potential for daily fluctuation in PD symptoms means single measures of treatment effectiveness can result in bias in effect estimates and hence repeated measures are recommended.

Irreversible motor impairment in young addicts--ephedrone, manganism or both?

BACKGROUND: Parkinsonian syndrome related to intravenous use of a "designer" psychostimulant, derived from pseudoephedrine using potassium permanganate as the oxidant, has been observed in drug addicts in Estonia. OBJECTIVE: To describe the symptomatology of four young patients, history of drug administration and chemical analysis of a drug batch. METHODS: Mental and motor function and quality of life were scored and ephedrone was analyzed using electrospray mass spectrometry. Manganese content of the final synthetic mixture was analyzed using Inductively Coupled Plasma-Atomic Emission Spectrometry. RESULTS: None of the four cases scored below the dementia threshold in MMSE, while other ratings (UPDRS, H&Y, PDQ-39) corresponded to disabilities seen in relatively advanced Parkinson's disease. The ephedrone yield of the reaction was approximately 44% and the mixture was found to contain 0.6 g/l of manganese. CONCLUSIONS: The cases were exposed to extreme manganese load. Their symptomatology is probably identical to manganism. The role of ephedrone is presently unknown. Physicians must be aware of early signs of manganism in patients within social risk groups.

Outcome prediction of enteral levodopa/carbidopa infusion in advanced Parkinson's disease.

Two studies comparing intraduodenal infusion of a levodopa/carbidopa gel with oral treatments in advanced PD patients demonstrated improvement in UPDRS scores and in frequent clinical ratings on a global treatment response scale. Further analysis of data from these studies was performed to find predictive factors related to degree of improvement with infusion. Pearson's correlation coefficients between measures of improvement and baseline variables were calculated. Using data from one study, a prediction model was designed and was then evaluated using the other study's data. Correlations were found indicating that patients with more severe symptoms at baseline were most improved after infusion.

Duodenal levodopa infusion monotherapy vs oral polypharmacy in advanced Parkinson disease.

OBJECTIVES: To compare daytime intraduodenal levodopa/carbidopa infusion as monotherapy with individually optimized conventional combination therapies in patients with advanced Parkinson disease (PD) for motor fluctuations and quality of life (QoL). METHODS: Twenty-four patients with motor fluctuations and dyskinesia were studied in a randomized crossover design to compare individualized conventional treatment and intraduodenal infusion of a levodopa/carbidopa gel for 3 + 3 weeks. Video scoring of motor function was assessed by blinded assessors on a global Treatment Response Scale from -3 to 0 to +3 (from severe "off" to "on" to "on" with severe dyskinesia). Patient self-assessment of motor performance and QoL was done using an electronic diary. RESULTS: Median percentage of ratings in a functional "on" interval (-1 to +1) was increased from 81 to 100% by infusion therapy (p < 0.01). This improvement was accompanied by a decrease in "off" state (p < 0.01) and no increase in dyskinesia. Median Unified Parkinson's Disease Rating Scale score decreased from 53 to 35 in favor of infusion (p < 0.05). QoL was improved, using the two instruments: Parkinson's Disease Questionnaire-39 and 15D Quality of Life Instrument (p < 0.01). Adverse events were similar for both treatment strategies. CONCLUSIONS: Continuous intraduodenal infusion of the levodopa/carbidopa enteral gel as monotherapy is safe and clinically superior to a number of individually optimized combinations of conventional oral and subcutaneous medications in patients with motor fluctuations. Intraduodenal infusion of levodopa offers an important alternative in treating patients with advanced Parkinson disease.

Duodenal levodopa infusion in Parkinson's disease--long-term experience.

Motor fluctuations in parkinsonian patients can be reduced by intraduodenal infusion of levodopa. Between 1991 and 1998 continuous daytime administration of levodopa through a transabdominal port has been used in 28 very advanced patients over a total period of 1045 months. A stable suspension of levodopa and carbidopa (Duodopa) has been developed. Patients were characterized by early onset, long history of disease and levodopa therapy. The reason for infusion was in all cases related to on-off fluctuations. All patients experienced a general improvement after the introduction of continuous treatment. There have been no severe complications. Six patients have taken the decision to curtail their treatment. The mean daily levodopa consumption has been slightly reduced on infusion as compared to oral therapy. Nine of the first group of patients participating in the new therapy have been regularly evaluated by means of rating scales and movement analyses. Short-term results have already been published and a follow-up showing continued positive effect after 4-7 years of continuous duodenal infusion is presented.