COMPARATIVA DE NIVELES PLASMÁTICOS, IMPLICACIONES CLÍNICAS Y COSTES ENTRE PACIENTES TRATADOS CON VALPROICO ENDOVENOSO GENÉRICO FRENTE A PACIENTES TRATADOS CON VALPROICO ENDOVENOSO INNOVADOR.

Abstract

In order to maximize cost savings, health care systems recommend the use of generic drugs. Its main advantage is lower cost, due to savings in research. However, small variations in bioavailability among generic drugs and brand-name drugs in epilepsy may be associated with negative effects with significant clinical changes (loss of seizure control, loss of jobs / driving license). There are multiple cases series with loss seizure control or adverse events, but there are few studies to draw conclusions about its total interchangeability in antiepileptic drugs._x000D_ Objectives: To compare drug concentrations, seizure control, adverse effects and costs in patients treated with intravenous valproic generic among patients treated intravenous brand-name valproic in the target patient population (patients hospitalized with multiple administrations, different comorbidities and polytherapy)._x000D_ Methods: Retrospective observational study in which we compared two periods: Period 1: 2003-2006 patients receiving “Depakine” ® (brand-name). Period 2: 2007-2010 patients receiving “Ácido valproico GES EFG” ® (generic)._x000D_ Results: We included 49 patients in the brand-name group and 103 in the generic group. Objective 1: There were not differences in drug concentrations between the 2 groups (38.58 vs. 38.75 mcg / mL.). On stratification by dose, with the dose of 1200 mg/day, low drug concentrations were detected in the generic group (51.06 mcg / mL vs. 34.76 mcg / mL, p = 0.025). Objective 2: Baseline seizure frequency was similar in both groups (38.8% vs. 41.7 %). Subsequently, the brand-name group had a trend toward significance better seizure control (83.7% vs. 68.9%, p = 0.075). On multivariable analysis, the diagnosis of status epilepticus was found to be associated as a risk factor predictive of seizures (OR: 4.9 (1.94-12.4)). Objective 3: There was no relationship between adverse effects and drug concentration. Longer treatment was associated with an increase in adverse effects (11 vs. 5 days, p = 0.009.). There were no differences of adverse effects between the two groups. Objective 4: The cost of valproico treatment was higher in the brand-name group (241.72 vs. € 98.79, p = 0.0001). However, there were no differences in cost in patients with seizures (134.05 vs. € 143.23)._x000D_ Conclusions: Objective 1: Only one third of the monitored patients had therapeutic levels (50-100 mcg/mL). In general, there were not differences in mean valproico drug concentrations between both groups. However, with the dose of 1200 mg/day, the generic group had lower concentrations than brand-name group. Objective 2: The brand-name group had a trend for better control seizure. On multivariable analysis, the diagnosis of status epilepticus was associated with loss seizure control (higher incidence in the generic group with non-significant). Objective 3: There was no relationship between adverse effects and drug concentration. After discarding confounding factors, the use of generic could not relate to a different profile of adverse effects. Objective 4: Generic prescription decreased cost 7.50 €/day, resulting in a savings of almost 150 €/treatment. However, the use of generic VPA IV is a only less expensive in seizure-free patients.

Date of Award	3 Oct 2014
Original language	Spanish
Supervisor	Jaime Roquer Gonzalez (Director) & Antonio Mur Sierra (Director)