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.FundingAbbVie, Inc.Plain Language SummaryPlain language summary available for this article.

Interferon-alpha (IFN-alpha) inhibits the development of diabetes in animal models of autoimmune diabetes. However, the mechanism of the action is not fully understood and drug toxicity could limit its potential clinical utility. Interferon-tau (IFN-tau) is another type 1 interferon, which has less toxicity but may have different biologic activity than IFN-alpha. This study explores the effect of IFN-tau on the diabetic process in non-obese diabetic (NOD) mice. IFN-tau by intraperitoneal, subcutaneous, or oral routes of administration decreased the development of spontaneous diabetes in NOD mice. Islet inflammation was decreased 50%. IFN-tau administration to recipient mice prevented the development of passively transferred and cyclophosphamide accelerated diabetes. IFN-tau treatment also decreased anti-islet effector activity of NOD splenic cells. Immunoregulatory activity of splenic cells was augmented by IFN-tau administration as was the number of splenic CD25+CD4+ cells. Concanavalin A (Con A)-induced release of IFN-gamma was decreased in spleen cells from IFN-tau treated mice. In conclusion, IFN-tau inhibits spontaneous autoimmune diabetes and passively transferred diabetes in the NOD mouse. This diabetes sparing activity may be due to an induction of regulatory cells, possibly CD25+CD4+ T cells, which in turn inhibit anti-islet effector cell activity and the development of insulitis and diabetes. Due to the lower drug toxicity, IFN-tau could be a better drug candidate than IFN-alpha for experimental clinical trials.

Treatment of patients with a-synucleinopathies (e.g., Parkinson disease, multiple system atrophy, diffuse Lewy body disease) may require clinicians to manage both neurologic and cardiovascular issues due to autonomic dysfunction.In addition to the underlying neurodegenerative condition, patients often experience blood pressure dysregulation, such as neurogenic orthostatic hypotension (nOH) and/or supine hypertension. This commentary details the collaborative care between a cardiologist and neurologist to effectively manage medically complex patients with nOH by illustrating the case of a 76-year-old man with a history of multiple system atrophy who experienced recurrent syncope when standing or sitting and falls with loss of consciousness. The patient could walk only a few steps before experiencing a substantial drop in systolic blood pressure (100 mmHg). He also had features of profound parkinsonism (e.g., tremor, facial masking) that required treatment with levodopa, but orthostatic symptoms related to the blood pressure drop needed improvement first. The neurologist and cardiologist collaborated to diagnose nOH and initiate droxidopa treatment, which led to resolution of syncope, control of orthostatic symptoms, and improvement of orthostatic blood pressure. Considerations in the collaborative care of patients with nOH are outlined, including screening protocols, treatment goals and options, mitigation of supine hypertension risk (a condition that frequently coexists with nOH), and management of other comorbidities. In conclusion, collaboration between neurologists and cardiologists is an efficient method to improve outcomes for patients with nOH because this care model allows specialist providers to leverage their areas of expertise to manage the wide spectrum of clinical features associated with nOH. Further, communication and cooperation of the patient care team can lead to reduced patient morbidity, optimal relief of nOH symptoms, improvements in activities of daily living and quality of life, and decreased caregiver burden.

Droxidopa is approved for the treatment of neurogenic orthostatic hypotension (nOH) symptoms and requires patients to be titrated to individualized effective doses (100–600 mg, three times daily) based on symptomatic response. As per the product label, droxidopa should be titrated every 24–48 hours to an optimum maintenance dose (maximum daily dosage 1,800 mg). In an examination of patients with nOH treated in clinical practice settings (n=4,506) using data from the central Northera specialty-pharmacy hub, titration schedules, daily titration dosage (ie, dosage during first dispensation, the assumed titration period), and daily maintenance dosage (dosage during subsequent dispensations) were characterized. It was found that customized titration schedules (ie, different from the product-label recommendation) had been used in 53% of patients, and these patients had had an average daily titration dosage of 567 mg. In contrast, patients who were titrated as per the label schedule (48 hours, 37%; 24 hours, 10%) had daily titration dosages of 1,500–1,650 mg. A relationship between treatment persistence (measured by number of refills) and maintenance dosage was identified. Average daily maintenance doses in patients who received 2, 3–6, 7–24, and >25 dispensations were 938, 969, 1,069, and 1,167 mg, respectively ( P <0.0001). In summary, our data suggest that more than half the patients treated with droxidopa in clinical practice settings are not titrated using the schedule recommended on the product label (ie, not 24–48 hours), and as a result receive lower daily dosages of droxidopa than those treated using the recommended titration schedules. Lower daily maintenance dosages of droxidopa were associated with shorter treatment persistence (ie, fewer dispensations). Reasons for discontinuation could not be examined in this study, but further investigation of these persistence data is warranted.