Pramipexole

Evidence Level: L4

Predicted Indications: 10

Pramipexole
Pramipexole: From Restless Legs Syndrome and Parkinson Disease to Attention Deficit-Hyperactivity Disorder

## Pharmacist Assessment Report

Pramipexole: From Restless Legs Syndrome and Parkinson Disease to Attention Deficit-Hyperactivity Disorder

One-Sentence Summary

Pramipexole is a dopamine agonist originally used to treat restless legs syndrome and Parkinson disease. The TxGNN model predicts it may be effective for attention deficit-hyperactivity disorder (ADHD), but the support is indirect: there are no registered clinical trials and only 7 publications (reviews, case reports, one Tourette's syndrome RCT and mechanistic work, none of them ADHD-specific). Among the other predicted indications, schizophrenia has the strongest supporting evidence (1 Phase 3 trial and a randomized controlled trial), and it is discussed under the conclusion.

Quick Overview

Item	Content
Original Indication	Restless legs syndrome; Parkinson disease (the Singapore licences carry no indication text, so these come from the knowledge graph)
Predicted New Indication	Attention deficit-hyperactivity disorder
TxGNN Prediction Score	99.998%
Evidence Level	L4
Singapore Market Status	✓ Marketed
Number of Registrations	3
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism of action data is not available in the data compiled for this report. Pramipexole is known as a dopamine D2/D3 receptor agonist. It is used in Parkinson disease and restless legs syndrome, where dopaminergic signalling is central.

Dopamine dysregulation is also implicated in ADHD. Variants of the dopamine D4 receptor gene have been associated with ADHD, so a dopaminergic drug is a plausible candidate. This is a mechanistic argument only. The literature compiled includes a case report of a patient with ADHD who received pramipexole together with atomoxetine for pain, a Tourette's syndrome RCT and general restless legs syndrome reviews. None of these tests pramipexole as a treatment for ADHD itself. The very high TxGNN score is a computational prediction and does not replace clinical evidence.

Clinical Trial Evidence

Currently no related clinical trials registered for ADHD.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
22407510	2012	RCT	Movement Disorders	Multicentre placebo-controlled trial of pramipexole in Tourette's syndrome, a related neuropsychiatric condition, based on the idea of dopamine hypersensitivity
19412489	2006	Review	Neuropsychiatric Disease and Treatment	Pramipexole, a D3-selective agonist, in restless legs syndrome
18656214	2008	Review	Revue Neurologique	Overview of restless legs syndrome (not ADHD-specific)
37342213	2023	Case report	Frontiers in Pain Research	Remission of chronic low back pain and oral dysesthesia in a patient with comorbid ADHD treated with atomoxetine and pramipexole
34182128	2021	Preclinical	Pharmacological Research	Interaction between α2A adrenoceptors and dopamine D4 receptor variants, relevant to ADHD and impulsive-control disorders
24992083	2014	Clinical study	Clinical Neuropharmacology	Piribedil compared with pramipexole and ropinirole on vigilance in Parkinson disease (different drug and disease)

Singapore Market Information

Authorization Number	Product Name	Dosage Form	Approved Indication
SIN13930P	Sifrol Extended Release Tablet 1.5mg	Extended-release tablet	Not stated in the data compiled
SIN13928P	Sifrol Extended Release Tablet 0.375 mg	Extended-release tablet	Not stated in the data compiled
SIN11253P	SIFROL TABLET 0.125 mg	Tablet	Not stated in the data compiled

All three licences are valid single-ingredient products, and none is cancelled.

Safety Considerations

Contraindications and conditions of concern (from the knowledge graph, not label text): orthostatic hypotension, multiple system atrophy, postural orthostatic tachycardia syndrome, drug-induced dyskinesia, psychotic disorders (including schizophreniform and schizoaffective disorder), kidney disease, melanoma, sleep apnoea and narcolepsy-related conditions, and central nervous system disease.
Drug interactions: 100 interactions were found. Those with a moderate level include morphine (including liposomal), opium, cimetidine, metoclopramide, dronabinol and nabilone. Ranitidine is a minor interaction. Others, such as pantoprazole, metformin and omeprazole, have an unknown severity level.
Dopamine agonists can worsen psychosis, which matters for any psychiatric use. Gambling disorder has also been associated with pramipexole in a Swedish register study.

Please refer to the package insert for the full warnings, as label text was not available.

Conclusion and Next Steps

Decision: Hold

Rationale: For ADHD, the support is a computational prediction plus indirect literature. There are no ADHD trials, and the evidence level is L4. Safety information from the label has not been obtained, and the knowledge graph lists psychotic disorders among the contraindicated conditions.

To proceed, the following is needed:

ADHD-specific clinical data, starting with a small controlled study
The Singapore package insert (HSA) with warnings and contraindications, and the detailed mechanism of action data
A safety plan covering psychiatric adverse effects, impulse-control problems, sleepiness and orthostatic hypotension

Note on other predictions: Schizophrenia (score 99.52%) is the best-supported alternative, at evidence level L2 and recommendation "Research Question". Support includes a 16-week placebo-controlled RCT of add-on pramipexole (PMID 35921506, n=200) and a Phase 3 add-on trial, NCT01320982 (n=400, status unknown, no results, multiple arms). Because dopamine agonists may worsen psychosis, any move in that direction would need strict guardrails. The remaining predictions (for example faciodigitogenital syndrome, chondromyxoid fibroma and several rare congenital disorders) rest on the model score alone and should stay on hold.

Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.