-
Medicine Sep 2023Atypical antipsychotic (AAP) augmentation is an alternative strategy for patients with major depressive disorder (MDD) who had an inadequate response to antidepressant... (Meta-Analysis)
Meta-Analysis
Comparative efficacy and safety of 4 atypical antipsychotics augmentation treatment for major depressive disorder in adults: A systematic review and network meta-analysis.
BACKGROUND
Atypical antipsychotic (AAP) augmentation is an alternative strategy for patients with major depressive disorder (MDD) who had an inadequate response to antidepressant therapy (ADT). We aimed to compare and rank the efficacy and safety of 4 AAPs in the adjuvant treatment of MDD.
METHODS
We searched randomized controlled trials (RCTs) published and unpublished from the date of databases and clinical trial websites inception to April 30, 2023. The evidence risk of bias (RoB) and certainty are assessed using the Cochrane bias risk tool and grading of recommendations assessment, development, and evaluation (GRADE) framework, respectively. Using network meta-analysis, we estimated summary risk ratios (RRs) or standardized mean difference (SMD) based on the random effects model.
RESULTS
56 eligible studies comprising 11448 participants were included. In terms of primary efficacy outcome, compared with placebo (PBO), all AAPs had significant efficacy (SMD = -0.40; 95% CI, -0.68 to -0.12 for quetiapine (QTP); -0.35, -0.59 to -0.11 for olanzapine (OLA); -0.28, -0.47 to -0.09 for aripiprazole (ARI) and -0.25, -0.42 to -0.07 for brexpiprazole (BRE), respectively). In terms of acceptability, no significant difference was found, either agents versus agents or agents versus PBO. In terms of tolerability, compared with the PBO, QTP (RR = 0.24; 95% CI,0.11-0.53), OLA (0.30,0.10-0.55), ARI (0.39,0.22-0.69), and BRE (0.37,0.18-0.75) were significantly less well tolerated. 8 (14.2%) of 56 trials were assessed as low RoB, 38 (67.9%) trials had moderate RoB, and 10 (17.9%) had high RoB; By the GRADE, the certainty of most evidence was low or very low.
CONCLUSION
Adjuvant AAPs had significant efficacy compared with PBO, but treatment decisions must be made to balance the risks and benefits.
Topics: Adult; Humans; Depressive Disorder, Major; Antipsychotic Agents; Network Meta-Analysis; Quetiapine Fumarate; Aripiprazole; Olanzapine; Adjuvants, Immunologic; Adjuvants, Pharmaceutic
PubMed: 37746943
DOI: 10.1097/MD.0000000000034670 -
CNS Drugs Dec 2022Research comparing levodopa/carbidopa intestinal gel (LCIG), deep brain stimulation (DBS), and continuous subcutaneous apomorphine infusion (CSAI) for advanced... (Meta-Analysis)
Meta-Analysis
Comparative Effectiveness of Device-Aided Therapies on Quality of Life and Off-Time in Advanced Parkinson's Disease: A Systematic Review and Bayesian Network Meta-analysis.
INTRODUCTION
Research comparing levodopa/carbidopa intestinal gel (LCIG), deep brain stimulation (DBS), and continuous subcutaneous apomorphine infusion (CSAI) for advanced Parkinson's disease (PD) is lacking. This network meta-analysis (NMA) assessed the comparative effectiveness of LCIG, DBS, CSAI and best medical therapy (BMT) in reducing off-time and improving quality of life (QoL) in patients with advanced PD.
METHODS
A systematic literature review was conducted for randomized controlled trials (RCTs), observational and interventional studies from January 2003 to September 2019. Data extracted at baseline and 6 months were off-time, as reported by diary or Unified Parkinson's Disease Rating Scale Part IV item 39, and QoL, as reported by Parkinson's Disease Questionnaire (PDQ-39/PDQ-8). Bayesian NMA was performed to estimate pooled treatment effect sizes and to rank treatments in order of effectiveness.
RESULTS
A total of 22 studies fulfilled the inclusion criteria (n = 2063 patients): four RCTs, and 16 single-armed, one 2-armed and one 3-armed prospective studies. Baseline mean age was between 55.5-70.9 years, duration of PD was 9.1-15.3 years, off-time ranged from 5.4 to 8.7 h/day in 9 studies, and PDQ scores ranged from 28.8 to 67.0 in 19 studies. Levodopa/carbidopa intestinal gel and DBS demonstrated significantly greater improvement in off-time and QoL at 6 months compared with CSAI and BMT (p < 0.05). There was no significant difference in the effects of LCIG and DBS, but DBS was ranked first for reduction in off-time, and LCIG was ranked first for improvement in QoL.
CONCLUSIONS
This NMA found that LCIG and DBS were associated with superior improvement in off-time and PD-related QoL compared with CSAI and BMT at 6 months after treatment initiation. This comparative effectiveness research may assist providers, patients, and caregivers in the selection of the optimal device-aided therapy.
Topics: Humans; Middle Aged; Aged; Carbidopa; Levodopa; Quality of Life; Network Meta-Analysis; Parkinson Disease; Apomorphine
PubMed: 36414908
DOI: 10.1007/s40263-022-00963-9 -
Pituitary Feb 2023This systematic literature review investigated whether extended dosing intervals (EDIs) of pharmacological acromegaly treatments reduce patient burden and costs compared...
PURPOSE
This systematic literature review investigated whether extended dosing intervals (EDIs) of pharmacological acromegaly treatments reduce patient burden and costs compared with standard dosing, while maintaining effectiveness.
METHODS
MEDLINE/Embase/the Cochrane Library (2001-June 2021) and key congresses (2018-2021) were searched and identified systematic literature review bibliographies reviewed. Included publications reported on efficacy/effectiveness, safety and tolerability, health-related quality of life (HRQoL), and patient-reported and economic outcomes in longitudinal/cross-sectional studies in adults with acromegaly. Interventions included EDIs of pegvisomant, cabergoline, and somatostatin receptor ligands (SRLs): lanreotide autogel/depot (LAN), octreotide long-acting release (OCT), pasireotide long-acting release (PAS), and oral octreotide; no comparator was required.
RESULTS
In total, 35 publications reported on 27 studies: 3 pegvisomant monotherapy, 11 pegvisomant combination therapy with SRLs, 9 LAN, and 4 OCT; no studies reported on cabergoline, PAS, or oral octreotide at EDIs. Maintenance of normal insulin-like growth factor I (IGF-I) was observed in ≥ 70% of patients with LAN (1 study), OCT (1 study), and pegvisomant monotherapy (1 study). Achievement of normal IGF-I was observed in ≥ 70% of patients with LAN (3 studies) and pegvisomant in combination with SRLs (4 studies). Safety profiles were similar across EDI and standard regimens. Patients preferred and were satisfied with EDIs. HRQoL was maintained and cost savings were provided with EDIs versus standard regimens.
CONCLUSIONS
Clinical efficacy/effectiveness, safety, and HRQoL outcomes in adults with acromegaly were similar and costs lower with EDIs versus standard regimens. Physicians may consider acromegaly treatment at EDIs, especially for patients with good disease control.
Topics: Adult; Humans; Acromegaly; Octreotide; Insulin-Like Growth Factor I; Cabergoline; Cross-Sectional Studies; Quality of Life; Peptides, Cyclic; Human Growth Hormone
PubMed: 36447058
DOI: 10.1007/s11102-022-01285-1 -
Journal of Psychiatric Research Jun 2024Variability in hepatic cytochrome P450 (CYP) enzymes such as 2C19 and 2D6 may influence side-effect and efficacy outcomes for antipsychotics. Aripiprazole and... (Review)
Review
Variability in hepatic cytochrome P450 (CYP) enzymes such as 2C19 and 2D6 may influence side-effect and efficacy outcomes for antipsychotics. Aripiprazole and risperidone are two commonly prescribed antipsychotics, metabolized primarily through CYP2D6. Here, we aimed to provide an overview of the effect of CYP2C19 and CYP2D6 on side-effects of aripiprazole and risperidone, and expand on existing literature by critically examining methodological issues associated with pharmacogenetic studies. A PRISMA compliant search of six electronic databases (Pubmed, PsychInfo, Embase, Central, Web of Science, and Google Scholar) identified pharmacogenetic studies on aripiprazole and risperidone. 2007 publications were first identified, of which 34 were included. Quality of literature was estimated using Newcastle-Ottowa Quality Assessment Scale (NOS) and revised Cochrane Risk of Bias tool. The average NOS score was 5.8 (range: 3-8) for risperidone literature and 5 for aripiprazole (range: 4-6). All RCTs on aripiprazole were rated as high risk of bias, and four out of six for risperidone literature. Study populations ranged from healthy volunteers to inpatient individuals in psychiatric units and included adult and pediatric samples. All n = 34 studies examined CYP2D6. Only one study genotyped for CYP2C19 and found a positive association with neurological side-effects of risperidone. Most studies did not report any relationship between CYP2D6 and any side-effect outcome. Heterogeneity between and within studies limited the ability to synthesize data and draw definitive conclusions. Studies lacked statistical power due to small sample size, selective genotyping methods, and study design. Large-scale randomized trials with multiple measurements, providing robust evidence on this topic, are suggested.
Topics: Humans; Aripiprazole; Cytochrome P-450 CYP2D6; Risperidone; Cytochrome P-450 CYP2C19; Antipsychotic Agents
PubMed: 38631139
DOI: 10.1016/j.jpsychires.2024.04.001 -
BMC Endocrine Disorders Nov 2021Prolactinoma is the major cause of hyperprolactinemia, and dopamine agonists (DAs) are generally the first-line treatment for them. Several studies have reviewed the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Prolactinoma is the major cause of hyperprolactinemia, and dopamine agonists (DAs) are generally the first-line treatment for them. Several studies have reviewed the recurrent rate of hyperprolactinemia after DAs withdrawal. However, few of them have concerned the recurrence risk of prolactinoma following the withdrawal of DAs.
METHODS
Three medical databases, PubMed, EMBASE and Cochrane library, were retrieved up to February, 14, 2021 to identify studies related to recurrence of prolactinoma and withdrawal of DAs. Statistical analyses including meta-analysis, sensitivity analysis, meta-regression, funnel plot and Egger test were performed through software R.
RESULTS
A total of 3225 studies were retrieved from the three data bases, and 13 studies consisted of 616 patients and 19 arms were finally included in this systematic analysis. There was no significant heterogeneity among the included studies, and fixed effect model was thus used. The pooled recurrence proportion of prolactinoma after withdrawal of DA was 2% with a 95% confidence interval (CI) of 1-3%.
CONCLUSION
Our study showed a very low recurrent rate of prolactinomas after DAs withdrawal. Much more prospective studies with larger cases and longer follow-up period are encouraged to confirm our finding.
TRIAL REGISTRATION
Registration number CRD42021245888 (PROSPERO).
Topics: Bromocriptine; Cabergoline; Deprescriptions; Dopamine Agonists; Humans; Neoplasm Recurrence, Local; Pituitary Neoplasms; Prolactinoma
PubMed: 34774043
DOI: 10.1186/s12902-021-00889-1 -
PloS One 2024To report the first and largest systematic review and meta-analysis of randomized controlled trials (RCT) to evaluate the efficacy and safety of aripiprazole or... (Meta-Analysis)
Meta-Analysis
Efficacy and safety of aripiprazole or bupropion augmentation and switching in patients with treatment-resistant depression or major depressive disorder: A systematic review and meta-analysis of randomized controlled trials.
OBJECTIVES
To report the first and largest systematic review and meta-analysis of randomized controlled trials (RCT) to evaluate the efficacy and safety of aripiprazole or bupropion augmentation and switching in patients with treatment-resistant depression (TRD) or major depressive disorder(MDD).
METHODS
We conducted a systematic literature retrieval via PubMed, Embase, Web of Science, and Cochrane until April 2023 for RCT, which evaluated the efficacy and safety of aripiprazole or bupropion augmentation and switching for patients with TRD or MDD. Outcomes measured were changes in the Montgomery-Asberg Depression Rating Scale (MADRS), response and remission rate, and serious adverse events.
RESULTS
Five RCTs, including 4480 patients, were included for meta-analysis. Among them, two RCTs were rated as "high risk" in three aspects (allocation concealment, blinding of participants and personnel and blinding of outcome assessment) because of the non-blind method, and the quality evaluation of the remaining works of literature was "low risk". Augmentation treatment with Aripiprazole (A-ARI) was associated with a significant higher response rate compared with augmentation treatment with bupropion (A-BUP) (RR: 1.15; 95% CI: 1.05, 1.25; P = 0.0007; I2 = 23%). Besides, A-ARI had a significant higher remission rate compared with switching to bupropion (S-BUP) (RR: 1.22; 95% CI: 1.00, 1.49; P = 0.05; I2 = 59%) and A-BUP had a significant higher remission rate compared with S-BUP (RR: 1.20; 95% CI: 1.06, 1.36; P = 0.0004; I2 = 0%). In addition, there was no significant difference in remission rate(RR: 1.05; 95% CI: 0.94, 1.17; P = 0.42; I2 = 33%), improvement of MADRS(WMD: -2.07; 95% CI: -5.84, 1.70; P = 0.28; I2 = 70%) between A-ARI and A-BUP. No significant difference was observed in adverse events and serious adverse events among the three treatment strategies.
CONCLUSIONS
A-ARI may be a better comprehensive antidepressant treatment strategy than A-BUP or S-BUP for patients with TRD or MDD. More large-scale, multi-center, double-blind RCTs are needed to further evaluated the efficacy and safety of aripiprazole or bupropion augmentation and switching treatment strategies.
Topics: Aripiprazole; Bupropion; Humans; Depressive Disorder, Major; Randomized Controlled Trials as Topic; Depressive Disorder, Treatment-Resistant; Treatment Outcome; Drug Therapy, Combination
PubMed: 38669232
DOI: 10.1371/journal.pone.0299020 -
The Cochrane Database of Systematic... Apr 2021Ovarian hyperstimulation syndrome (OHSS) is a potentially serious complication of ovarian stimulation in assisted reproduction technology (ART). It is characterised by... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Ovarian hyperstimulation syndrome (OHSS) is a potentially serious complication of ovarian stimulation in assisted reproduction technology (ART). It is characterised by enlarged ovaries and an acute fluid shift from the intravascular space to the third space, resulting in bloating, increased risk of venous thromboembolism, and decreased organ perfusion. Most cases are mild, but forms of moderate or severe OHSS appear in 3% to 8% of in vitro fertilisation (IVF) cycles. Dopamine agonists were introduced as a secondary prevention intervention for OHSS in women at high risk of OHSS undergoing ART treatment. OBJECTIVES: To assess the effectiveness and safety of dopamine agonists in preventing OHSS in women at high risk of developing OHSS when undergoing ART treatment.
SEARCH METHODS
We searched the following databases from inception to 4 May 2020: Cochrane Gynaecology and Fertility Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and PsycINFO for randomised controlled trials (RCTs) assessing the effect of dopamine agonists on OHSS rates. We also handsearched reference lists and grey literature.
SELECTION CRITERIA
We considered RCTs for inclusion that compared dopamine agonists with placebo/no intervention or another intervention for preventing OHSS in ART. Primary outcome measures were incidence of moderate or severe OHSS and live birth rate. Secondary outcomes were rates of clinical pregnancy, multiple pregnancy, miscarriage, and adverse events.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened titles, abstracts, and full texts of publications; selected studies; extracted data; and assessed risk of bias. We resolved disagreements by consensus. We reported pooled results as odds ratios (OR) and 95% confidence interval (CI) by the Mantel-Haenszel method. We applied GRADE criteria to judge overall quality of the evidence.
MAIN RESULTS
The search identified six new RCTs, resulting in 22 included RCTs involving 3171 women at high risk of OHSS for this updated review. The dopamine agonists were cabergoline, quinagolide, and bromocriptine. Dopamine agonists versus placebo or no intervention Dopamine agonists probably lowered the risk of moderate or severe OHSS compared to placebo/no intervention (OR 0.32, 95% CI 0.23 to 0.44; 10 studies, 1202 participants; moderate-quality evidence). This suggests that if the risk of moderate or severe OHSS following placebo/no intervention is assumed to be 27%, the risk following dopamine agonists would be between 8% and 14%. We are uncertain of the effect of dopamine agonists on rates of live birth (OR 0.96, 95% CI 0.60 to 1.55; 3 studies, 362 participants; low-quality evidence). We are also uncertain of the effect of dopamine agonists on clinical pregnancy, multiple pregnancy, miscarriage or adverse events (very low to low-quality evidence). Dopamine agonists plus co-intervention versus co-intervention Dopamine agonist plus co-intervention (hydroxyethyl starch, human albumin, or withholding ovarian stimulation 'coasting') may decrease the risk of moderate or severe OHSS compared to co-intervention (OR 0.48, 95% CI 0.28 to 0.84; 4 studies, 748 participants; low-quality evidence). Dopamine agonists may improve rates of live birth (OR 1.21, 95% CI 0.81 to 1.80; 2 studies, 400 participants; low-quality evidence). Dopamine agonists may improve rates of clinical pregnancy and miscarriage, but we are uncertain if they improve rates of multiple pregnancy or adverse events (very low to low-quality evidence). Dopamine agonists versus other active interventions We are uncertain if cabergoline improves the risk of moderate or severe OHSS compared to human albumin (OR 0.21, 95% CI 0.12 to 0.38; 3 studies, 296 participants; very low-quality evidence), prednisolone (OR 0.27, 95% CI 0.05 to 1.33; 1 study; 150 participants; very low-quality evidence), hydroxyethyl starch (OR 2.69, 95% CI 0.48 to 15.10; 1 study, 61 participants; very low-quality evidence), coasting (OR 0.42, 95% CI 0.18 to 0.95; 3 studies, 320 participants; very low-quality evidence), calcium infusion (OR 1.83, 95% CI 0.88 to 3.81; I² = 81%; 2 studies, 400 participants; very low-quality evidence), or diosmin (OR 2.85, 95% CI 1.35 to 6.00; 1 study, 200 participants; very low-quality evidence). We are uncertain of the effect of dopamine agonists on rates of live birth (OR 1.08, 95% CI 0.73 to 1.59; 2 studies, 430 participants; low-quality evidence). We are uncertain of the effect of dopamine agonists on clinical pregnancy, multiple pregnancy or miscarriage (low to moderate-quality evidence). There were no adverse events reported.
AUTHORS' CONCLUSIONS
Dopamine agonists probably reduce the incidence of moderate or severe OHSS compared to placebo/no intervention, while we are uncertain of the effect on adverse events and pregnancy outcomes (live birth, clinical pregnancy, miscarriage). Dopamine agonists plus co-intervention may decrease moderate or severe OHSS rates compared to co-intervention only, but we are uncertain whether dopamine agonists affect pregnancy outcomes. When compared to other active interventions, we are uncertain of the effects of dopamine agonists on moderate or severe OHSS and pregnancy outcomes.
Topics: Abortion, Spontaneous; Administration, Oral; Aminoquinolines; Bromocriptine; Cabergoline; Dopamine Agonists; Ergolines; Female; Fertilization in Vitro; Humans; Live Birth; Ovarian Hyperstimulation Syndrome; Placebos; Pregnancy; Pregnancy Rate; Randomized Controlled Trials as Topic; Sperm Injections, Intracytoplasmic
PubMed: 33851429
DOI: 10.1002/14651858.CD008605.pub4 -
Movement Disorders Clinical Practice Sep 2023Continuous subcutaneous apomorphine infusion (CSAI) is one of the advanced therapies for Parkinson's disease (PD). (Review)
Review
BACKGROUND
Continuous subcutaneous apomorphine infusion (CSAI) is one of the advanced therapies for Parkinson's disease (PD).
METHODS
A systematic review of all published articles in English on CSAI for PD till January 30, 2022 was conducted.
RESULTS
A total of 82 articles met the search criteria. Publications included retrospective or prospective open-label observational studies, with a limited number of randomized control trials (RCT). Publications were highly heterogeneous and focused on different aspects of CSAI and included clinical audits, effects on cognition/behavior, axial symptoms, nocturnal issues, adverse events/reasons for discontinuation and comparison with other continuous dopaminergic therapies. CSAI was used in patients who presented severe motor fluctuations not resolved by oral therapy, poor candidates for deep brain stimulation (DBS) due to cognitive/behavioral issues or in those with DBS weaning effect. Recent studies have also shown that CSAI was useful for nocturnal usage in advanced PD, in addition to daytime utilization. Adverse effects were common and include skin lesions, sedation and nausea. Pump management difficulties and patient decisions were common reasons for therapy dropout, predominantly during the initial stages of the CSAI.
CONCLUSION
There is consistent agreement on the benefits of CSAI in reducing OFF periods and improving ON periods without troublesome dyskinesia and specific motor and non-motor symptoms. Although there is a paucity of RCTs, current data from almost 30 years of use suggests CSAI to be beneficial in advanced cases of PD.
Topics: Apomorphine; Parkinson Disease; Humans; Infusions, Subcutaneous; Antiparkinson Agents; Dopamine Agonists; Deep Brain Stimulation
PubMed: 37772305
DOI: 10.1002/mdc3.13810 -
Clinical Drug Investigation Apr 2021BACKGROUND AND OBJECTIVE: Safinamide is a novel anti-parkinsonian drug with possible anti-dyskinetic properties. Parkinson's disease (PD) is a complex disease. The... (Meta-Analysis)
Meta-Analysis
UNLABELLED
BACKGROUND AND OBJECTIVE: Safinamide is a novel anti-parkinsonian drug with possible anti-dyskinetic properties. Parkinson's disease (PD) is a complex disease. The objective of this systematic review and meta-analysis is to evaluate the efficacy and safety of safinamide administration compared to placebo in PD patients on multiple outcomes.
METHODS
PubMed, EMBASE, Cochrane CENTRAL, LILACS, and trial databases were searched up to 23 December 2020 for randomized controlled studies (RCTs) comparing safinamide to placebo, alone or as add-on therapy in PD. Data were extracted from literature and regulatory agencies. Primary outcomes were ON-time without troublesome dyskinesia, OFF-time, and Unified Parkinson's Disease Rating Scale (UPDRS) section III (UPDRS-III). Secondary outcomes included any dyskinesia rating scale (DRS), ON-time with troublesome dyskinesia, UPDRS-II, and Parkinson's Disease Questionnaire 39 (PDQ-39). In order to estimate mean difference (MD) and odds ratios with 95% confidence intervals (CI), generic inverse variance and Mantel-Haenszel methods were used for continuous and dichotomous variables, respectively. Analyses were performed grouping by PD with (PDwMF) or without (PDwoMF) motor fluctuations, safinamide dose, and concomitant dopaminergic treatment. Summary of findings with GRADE were performed.
RESULTS
Six studies with a total of 2792 participants were identified. In PDwMF patients, safinamide 100 mg as add-on to levodopa (L-dopa) significantly increased ON-time without troublesome dyskinesia (MD = 0.95 h; 95% CI from 0.41 to 1.49), reduced OFF-time (MD = - 1.06 h; 95% CI from - 1.60 to - 0.51), and improved UPDRS-III (MD = - 2.77; 95% CI from - 4.27 to - 1.28) with moderate quality of evidence. Similar results were observed for the 50 mg dose. However, the quality of evidence was moderate only for ON-time without troublesome dyskinesia, whereas for OFF-time and UPDRS-III was low. In PDwoMF patients taking a single dopamine agonist, safinamide 100 mg resulted in little to no clinically significant improvement in UPDRS-III (MD = - 1.84; 95% CI from - 3.19 to - 0.49), with moderate quality of evidence. Conversely, in PDwoMF patients, the 200 mg and 50 mg doses showed nonsignificant improvement in UPDRS-III, with very low and moderate quality of evidence, respectively. In PDwMF patients taking safinamide 100 mg or 50 mg, nonsignificant differences were observed for ON-time with troublesome dyskinesia and DRS, with high and low quality of evidence, respectively. In the same patients, UPDRS-II was significantly improved at the 100 mg and 50 mg dose, with high and moderate quality of evidence. In PDwoMF, UPDRS-II showed a little yet significant difference only at 100 mg, with low quality of evidence. PDQ-39 resulted significantly improved only with the 100 mg dose in PDwMF, with low quality of evidence.
CONCLUSION
Overall, safinamide is effective in PDwMF patients taking L-dopa both at 100 and 50 mg daily. Evidence for efficacy in early PD is limited. Further trials are needed to better evaluate the anti-dyskinetic properties of safinamide.
Topics: Alanine; Antiparkinson Agents; Benzylamines; Dopamine Agonists; Humans; Levodopa; Parkinson Disease; Randomized Controlled Trials as Topic
PubMed: 33674954
DOI: 10.1007/s40261-021-01011-y -
Frontiers in Cellular Neuroscience 2021The dopamine D1 receptor (D1R) is a Gα-coupled GPCR that is expressed in the midbrain and forebrain, regulating motor behavior, reward, motivational states, and...
The dopamine D1 receptor (D1R) is a Gα-coupled GPCR that is expressed in the midbrain and forebrain, regulating motor behavior, reward, motivational states, and cognitive processes. Although the D1R was initially identified as a promising drug target almost 40 years ago, the development of clinically useful ligands has until recently been hampered by a lack of suitable candidate molecules. The emergence of new non-catechol D1R agonists, biased agonists, and allosteric modulators has renewed clinical interest in drugs targeting this receptor, specifically for the treatment of motor impairment in Parkinson's Disease, and cognitive impairment in neuropsychiatric disorders. To develop better therapeutics, advances in ligand chemistry must be matched by an expanded understanding of D1R signaling across cell populations in the brain, and in disease states. Depending on the brain region, the D1R couples primarily to either Gα or Gα through which it activates a cAMP/PKA-dependent signaling cascade that can regulate neuronal excitability, stimulate gene expression, and facilitate synaptic plasticity. However, like many GPCRs, the D1R can signal through multiple downstream pathways, and specific signaling signatures may differ between cell types or be altered in disease. To guide development of improved D1R ligands, it is important to understand how signaling unfolds in specific target cells, and how this signaling affects circuit function and behavior. In this review, we provide a summary of D1R-directed signaling in various neuronal populations and describe how specific pathways have been linked to physiological and behavioral outcomes. In addition, we address the current state of D1R drug development, including the pharmacology of newly developed non-catecholamine ligands, and discuss the potential utility of D1R-agonists in Parkinson's Disease and cognitive impairment.
PubMed: 35110997
DOI: 10.3389/fncel.2021.806618