Sciegienka Anna, Argo Tami, Cantrell Matthew, Alexander Bruce
Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, USA.
Iowa City VA Health Care System, Iowa City, IA, USA.
Ann Pharmacother. 2015 Jun;49(6):670-3. doi: 10.1177/1060028015579197. Epub 2015 Mar 31.
Topiramate has been associated with metabolic acidosis secondary to decreased serum bicarbonate. Product labeling recommends serum bicarbonate monitoring at baseline and periodically thereafter.
The study objective was to assess changes in serum bicarbonate within the first year of topiramate use in an outpatient veteran population.
This was a single-center, retrospective study conducted at the Iowa City Veterans Affairs Health Care System. Inclusion criteria required a minimum of 1 topiramate outpatient prescription between October 1, 1999, and August 31, 2012, and at least 1 serum bicarbonate level within 12 months prior to topiramate initiation. Patients with topiramate nonadherence, concurrent use of sodium bicarbonate or oral carbonic anhydrase inhibitors, and individual serum bicarbonate values obtained during inpatient hospitalizations were excluded. Change in bicarbonate was evaluated using a paired t test. Decreases in bicarbonate of ≥5 mEq/L, values <20 mEq/L, days to lowest value, and correlation between adverse drug reactions (ADRs) and topiramate discontinuation were evaluated.
Of 546 patients reviewed, 350 were included in the analysis. There was a statistically significant decrease of 2.7 mEq/L in bicarbonate following initiation of topiramate. Only 1 patient had a bicarbonate value <17 mEq/L. There was no association between bicarbonate decrease ≥5 mEq/L and ADRs.
A statistically significant reduction in bicarbonate levels occurred with topiramate, which was clinically insignificant. ADR occurrence did not correlate with bicarbonate levels <17 mEq/L or a decrease ≥5 mEq/L. Our results indicate that serum bicarbonate levels should only be monitored before topiramate initiation and in patients presenting with symptoms suggestive of acidosis.
托吡酯与血清碳酸氢盐降低继发的代谢性酸中毒有关。产品标签建议在基线时监测血清碳酸氢盐，并在此后定期监测。
本研究的目的是评估在门诊退伍军人人群中使用托吡酯的第一年血清碳酸氢盐的变化。
这是一项在爱荷华市退伍军人事务医疗保健系统进行的单中心回顾性研究。纳入标准要求在1999年10月1日至2012年8月31日期间至少有1份托吡酯门诊处方，且在开始使用托吡酯前12个月内至少有1次血清碳酸氢盐水平检测。排除不依从托吡酯治疗、同时使用碳酸氢钠或口服碳酸酐酶抑制剂的患者，以及住院期间获得的个体血清碳酸氢盐值。使用配对t检验评估碳酸氢盐的变化。评估碳酸氢盐降低≥5 mEq/L、值<20 mEq/L、达到最低值的天数，以及药物不良反应（ADR）与停用托吡酯之间的相关性。
在审查的546例患者中，350例纳入分析。开始使用托吡酯后，碳酸氢盐在统计学上显著降低了2.7 mEq/L。只有1例患者的碳酸氢盐值<17 mEq/L。碳酸氢盐降低≥5 mEq/L与ADR之间无关联。
托吡酯使碳酸氢盐水平在统计学上显著降低，但在临床上无显著意义。ADR的发生与碳酸氢盐水平<17 mEq/L或降低≥5 mEq/L无关。我们的结果表明，仅应在开始使用托吡酯前以及出现酸中毒症状的患者中监测血清碳酸氢盐水平。
