A Practitioner’s Guide to Prescribing Tiagabine for Adults with Intellectual Disabilities

Abstract

We developed this tiagabine guideline using drug prescribing information and reviewing the available literature on relevant neuropsychiatric disorders in populations without intellectual disabilities because of the dearth of available literature on the population with intellectual disabilities. This guideline includes indications; contraindications; assessments prior to and during treatment; dosing with particular focus on dosing modifications required by drug–drug interactions, personal characteristics; and adverse drug reactions. The procedures contained in this guideline may not fully account for all of the possible risks of treatment in this population because of the limited studies available; thus, there will be a need to periodically update this guideline as new information becomes available. Nevertheless, we believe that this guideline provides a useful resource for clinicians who treat epilepsy in adult individuals with intellectual disabilities. A tiagabine drug utilization review that summarizes this guideline is described.

Appendix Drug Utilization Review: Tiagabine

DRUG UTILIZATION REVIEW CRITERIA				CRITERIA MET
TIAGABINE FOR ADULTS WITH IDs				YES	NO	NA
1) Indication: Check one of the following indications for use
	Adjunctive therapy for partial seizures.
	Other: Specify_________________________. When tiagabine is used for off-label indications, the chart will specifically include an explanatory note (Y___ N___).
To meet indication criteria at least one indication is present and documented.					
2) Dose:_____ Enzyme-inducing antiepileptics________________
	Tiagabine is administered with food.					
	The first antiepileptic dose in patients taking an enzyme-inducing antiepileptic was ≤ 4 mg (Y__ N__) unless otherwise recommended by a consultant with expertise in the area (Y__).					
	The maximum antiepileptic dosage in patients taking an enzyme-inducing antiepileptic was ≤ 56 mg/day (Y__ N__) unless otherwise recommended by a consultant with expertise in the area (Y__).					
	The first antiepileptic dose in patients NOT taking an enzyme-inducing antiepileptic was < 4 mg (Y__ N__) unless otherwise recommended by a consultant with expertise in the area (Y__).					
	The maximum antiepileptic dosage in patients NOT taking an enzyme-inducing antiepileptic was ≤ 22 mg/day (Y__ N__) unless otherwise recommended by a consultant with expertise in the area (Y__).					
	Taking other inducers____________________________. The chart documents the interaction (Y___ N___). The dosage of tiagabine may need to be increased when an inducer was added and the discontinuation of the inducer may need to be followed by a decrease of tiagabine dosage.					
	Taking potent CYP3A inhibitors (e.g., ketoconazole___, itraconazole___, fluconazole___, erythromycin___, fluoxetine___, fluvoxamine___, clarithromycin___, diltiazem___, or other________). The chart documents the interaction (Y___ N___). The dosage of tiagabine may need to be decreased when an inhibitor was added and the discontinuation of the inhibitor may need to be followed by an increase of tiagabine dosage.					
	Hepatic impairment_____. The chart documents slower titration and frequent monitoring (Y___ N___).					
To meet dose criteria all are Yes or NA.					
3) Relative contraindications: Check any present
	Pregnancy (Category C) or breast feeding.
	Hepatic insufficiency.
	History of status epilepticus.
If any of the above are checked, rationale is documented in chart to meet relative contraindication criteria. If none are present check NA.						
4) Baseline monitoring studies:
	Liver function tests.
	Serum concentrations of concomitantly administered antiepileptics, which are usually followed with therapeutic drug monitoring.
Answer Yes or No. If information is not applicable check NA.						
5) Discontinuation:
	Tiagabine is or was withdrawn slowly to minimize the potential of increased seizure frequency (Y___ N___). Abrupt withdrawal was justified by a major medical reason (Y___ N___).					
6) Adverse drug reactions (ADRs) due to tiagabine: Check left boxes to indicate which ADRs are present.
6.1) Common ADRs:
	Neuropsychiatric: decreased concentration, dizziness, nervousness, somnolence, weakness or tremor.		Gastrointestinal: nausea.
6.2) Relatively uncommon ADRs:
	Increased seizures, status epilepticus or exacerbations of EEG abnormalities.		Psychiatric symptoms: nervousness, depressive mood, emotional lability, psychosis, or confusion.
	Movement disorders, including dystonia or athetosis.		Spontaneous ecchymoses.
	Other_____________		Other_____________
6.3) Potentially lethal ADRs:
	Suicidal ideation or behavior.
Answer Yes (intervention or benefit/risk discussion after ADRs developed) or No (neither intervention nor benefit/risk discussion after ADRs developed) or NA (no abnormality developed).