Vitamins and Infusion of Levodopa-Carbidopa Intestinal Gel.

Levodopa-carbidopa intestinal gel infusion (LCIG) is an established therapy for advanced Parkinson disease (PD), resulting in a significant improvement of quality of life. With increased LCIG adoption worldwide, potential complications due to abnormal vitamin absorption or metabolism have been reported in these patients. Neurologists are unfamiliar with vitamins physiology and pathophysiological mechanisms in case of their deficiency. Unfortunately, clinical and laboratory guidelines related to vitamin monitoring and supplementation in the context of treatment with LCIG are not available. We herein summarize the current knowledge on three vitamins that are reduced with LCIG therapy reporting on their physiology, laboratory testing, and clinical impact of their deficiency/excess. In addition, we proposed an opinion-based recommendation for clinicians treating LCIG patients. Patients and caregivers should be informed about the risk of vitamin deficiency. Vitamin B12, homocysteine, and methylmalonic acid (MMA) should be tested before starting LCIG, six months after and once/year thereafter. Vitamin B6 and folate testing is not universally available but it should be considered if homocysteine is elevated but MMA and/or total vitamin B12 are normal. Prophylaxis of vitamin deficiency should be started as soon as LCIG is implemented, possibly even before. Dietary recommendations are enough in most patients although a subgroup of patients is at higher risk and should receive Vitamin B12 regularly and cycles of B6. Finally, once diagnosed a vitamin deficiency should be readily treated and accompanied by clinical and laboratory monitoring. Resistant cases should receive non-oral routes of administration and possibly discontinue LCIG, even temporarily.

Long-term results of carbidopa/levodopa enteral suspension across the day in advanced Parkinson's disease: Post-hoc analyses from a large 54-week trial.

Introduction: Carbidopa/levodopa enteral suspension (CLES) previously demonstrated reduction in total daily OFF from baseline by over 4 hours in advanced Parkinson's disease patients across 54 weeks. Evidence on CLES's long-term effectiveness on patterns of motor-symptom control throughout the day remains limited. Methods: We present post-hoc analyses of a large, open-label study of CLES monotherapy (N = 289). Diary data recorded patients' motor states at 30-minute intervals over 3 days at baseline and weeks 4, 12, 24, 36, and 54. Adjusted generalized linear mixed models assessed changes from baseline at each timepoint for four outcome measures: time to ON without troublesome dyskinesia (ON-woTD) after waking, motor-symptom control as measured by motor states' durations throughout the day, number of motor-state transitions, and presence of extreme fluctuations (OFF to ON with TD). Results: Patients demonstrated short-term (wk4) and sustained (wk54) improvement in all outcomes compared to baseline. At weeks 4 and 54, patients were more likely to reach ON-woTD over the course of their day (HR: 1.86 and 2.51, both P < 0.0001). Across 4-hour intervals throughout the day, patients also experienced increases in ON-woTD (wk4: 58-65 min; wk54: 60-78 min; all P < 0.0001) and reductions in OFF (wk4: 50-61 min; wk54: 56-68 min; all P < 0.0001). At weeks 4 and 54, patients' motor-state transitions were reduced by about half (IRR: 0.53 and 0.49, both P < 0.0001), and fewer patients experienced extreme fluctuations (OR: 0.22 and 0.15, both P < 0.0001). Conclusion: CLES monotherapy was associated with significant long-term reductions in motor-state fluctuations, faster time to ON-woTD upon awakening, and increased symptom control throughout the day.

Patterns of Daily Motor-Symptom Control with Carbidopa/Levodopa Enteral Suspension Versus Oral Carbidopa/Levodopa Therapy in Advanced Parkinson's Disease: Clinical Trial Post Hoc Analyses.

INTRODUCTION: A clinical trial in advanced Parkinson's disease (APD) has established the superiority of carbidopa/levodopa enteral suspension (CLES) in reducing total patient "off" time (OFF) and increasing total "on" time without troublesome dyskinesia (ON-woTD) over orally administered immediate-release carbidopa/levodopa tablets (IR-CL). However, temporal patterns of these improvements throughout the waking day have not been examined. In this analysis, time to ON-woTD after waking and patterns of motor-symptom control throughout the waking day were compared between CLES and IR-CL. METHODS: Post hoc analyses of APD patient-diary data from the phase 3 randomized controlled trial were used to compare changes in time to ON-woTD after waking, motor-symptom control throughout the waking day, occurrence of extreme fluctuations between OFF and "on" with troublesome dyskinesia, and motor-state transitions with CLES versus IR-CL from baseline to week 12. RESULTS: The sample included 33 CLES-treated and 30 IR-CL-treated patients. Among the CLES group, the percentage of patient days achieving ON-woTD within 30 min of waking was three times higher at week 12 versus baseline (33% vs. 11%, p = 0.0043); no significant change occurred with IR-CL. When the waking day was divided into four 4-h periods, CLES versus IR-CL treatment produced significantly greater reductions in OFF during three periods, and two periods had increased ON-woTD. Fewer CLES-treated patients had extreme fluctuations at week 12 (3% vs. 23%, p = 0.0224) compared to IR-CL-treated patients. From baseline to week 12, CLES-treated patients had greater reductions in the average number of motor-state transitions compared to IR-CL-treated patients (- 1.6, p = 0.0295). CONCLUSION: CLES-treated patients experienced a more rapid onset of ON-woTD after waking and greater consistency of ON-woTD throughout their waking day than IR-CL-treated patients.

In advanced Parkinson's disease, patients' motor-symptom states (such as "on" time without troublesome dyskinesia [good "on" time] and "off" time), and the timing at which they occur, can impact patients' quality of life and ability to complete activities of daily living. Carbidopa/levodopa enteral suspension is administered continuously into the jejunum, potentially reducing some of the motor-state variation that is common with orally administered carbidopa/levodopa, including delayed "on" time after waking and transitions between "off" and "on" throughout the day. In post hoc analyses of clinical trial data, patterns of motor-states across the waking day were compared between carbidopa/levodopa enteral suspension and orally administered immediate-release carbidopa/levodopa at week 12. Outcomes included time to good "on" after waking; occurrence of extreme fluctuations between "off" time and "on" time with troublesome dyskinesia; time in each motor-state during 4-h intervals across the day; and frequency of motor-state transitions. Three times as many carbidopa/levodopa enteral suspension-treated patients achieved good "on" within 30 min of waking after 12 weeks versus baseline, whereas no significant change was observed for the orally administered immediate-release carbidopa/levodopa group. Compared to orally administered immediate-release carbidopa/levodopa-treated patients, fewer carbidopa/levodopa enteral suspension-treated patients experienced extreme fluctuations, had greater reductions in motor-state transitions, and greater reductions in duration of "off" during three of the four intervals in the day. These findings provide a first look at the impact of carbidopa/levodopa enteral suspension on motor-state patterns throughout the day, and suggest that carbidopa/levodopa enteral suspension provides more consistent motor-symptom control and predictable benefit throughout the day than orally administered carbidopa/levodopa.

Current Practices for Outpatient Initiation of Levodopa-Carbidopa Intestinal Gel for Management of Advanced Parkinson's Disease in the United States.

In 2015, the US Food and Drug Administration approved levodopa-carbidopa intestinal gel (LCIG; also known as carbidopa-levodopa enteral suspension in the US) for the treatment of motor fluctuations in patients with advanced Parkinson's disease. LCIG provides a continuous infusion of levodopa and carbidopa by means of a portable pump and percutaneous endoscopic gastrojejunostomy tube. The delivery system has a two-fold pharmacokinetic advantage over orally administered carbidopa/levodopa. First, levodopa is delivered in a continuous rather than intermittent, pulsatile fashion. Second, delivery to levodopa's site of absorption in the jejunum bypasses the stomach, thereby avoiding issues with erratic gastric emptying. In blinded prospective clinical trials and observational studies, LCIG has been shown to significantly decrease "off" time, increase "on" time without troublesome dyskinesia, and reduce dyskinesia. Consistent with procedures in previous studies, LCIG initiation and titration in the pivotal US clinical trial were performed in the inpatient setting and followed a standardized protocol. In clinical practice, however, initiation and titration of LCIG have a great degree of flexibility and, in the US, almost always take place in the outpatient setting. Nonetheless, there remains a significant amount of clinician uncertainty regarding titration in outpatient clinical practice. This review aims to shed light on and provide guidance as to the current methods of titration in the outpatient setting, as informed by the medical literature and the authors' experiences. FUNDING: AbbVie, Inc. Plain language summary available for this article.

Results from recent studies have shown that continuous infusion of levodopa-carbidopa intestinal gel (LCIG) into the jejunum (a part of the small intestine) effectively manages the motor and nonmotor complications (e.g., tremor, extreme stiffness in arms and legs, difficulty walking, and impaired balance) experienced by patients with advanced Parkinson's disease (PD). LCIG is administered by a portable pump directly into the patient's jejunum by a permanent tube that is inserted surgically. LCIG therapy is beneficial to advanced PD patients over orally administered carbidopa/levodopa for two reasons. First, oral carbidopa/levodopa moves from the stomach to the small intestine where it is intermittently absorbed into the blood stream. LCIG is administered continuously and offers better symptom control for longer. Results from clinical trials and observational studies have shown that LCIG significantly decreases "off" time (poor motor control) and increases "on" time (good motor control) in advanced PD patients without troublesome dyskinesia, which results from the higher doses of oral levodopa required to treat the symptoms. Second, LCIG is absorbed in the jejunum, thereby bypassing the stomach where problems can occur because of inconsistent stomach emptying. In the US, titration of LCIG is performed mostly in an outpatient setting. Some clinicians may view titration of LCIG to be too complex and variable, so they avoid using LCIG therapy for their PD patients. Fortunately, emerging data and clinicians' expanding experience with LCIG have shown that titration can be easily managed in an outpatient setting, allowing for more customized therapeutic regimens for patients.