Insights in drug-drug interactions facilitate rational polypharmacy

An analysis of 2 American databases may help providers to use more rational polypharmacy. The chance of interaction increased as the number of combinations of abortives and preventives increased [1].

“Rational polypharmacy is common in the headache practice,” said Dr Victor Kaytser (Robert Wood Johnson Medical School, TX, USA). Migraine patients are often prescribed abortive and preventive medicines, as well as transition therapies. The current study aimed to estimate the probability of having an interaction of different medications.

Dr Kaytser and colleagues first listed commonly used abortive and preventive medicines, based on 2 papers: the American Headache Society Position Statement on integrating new migraine treatments into clinical practice and a paper on migraine care in the era of COVID-19 [2,3]. In total, 38 abortive medicines, including bridge medications, and 23 preventives, including valproic acid and amitriptyline, were included [1]. Neuromodulators were excluded. All possible combinations of ≤3 abortives and 3 preventives were obtained. To screen for interactions, the list was entered into the DrugBank and FDA Adverse Event Reporting System (FAERS) application programming interface. If ≥1 interaction of any type was listed for a combination of drugs, then that combination was considered as interacting.

The chance of an interaction increased as the number of combinations of abortives and preventives increased. Venlafaxine and candesartan were among the most interacting in the preventive drug groups. Venlafaxine and amitriptyline were among the most interacting in the abortive versus preventive groups. The calcitonin gene-related peptide (CGRP)-based therapies and botulin toxin appeared to be the least interacting preventive drugs. The least interacting abortives were triptans.

Dr Kaytser concluded that FAERS may provide a useful and relevant tool for making risk-benefit decisions when choosing a headache regimen. A limitation of this study was that the significance or severity of an interaction was uncertain. Furthermore, newer drugs were found to have fewer interactions, but that could be explained by the fact that they have been studied less. In the FAERS method, one report is sufficient to indicate a contraindication, but this is a conservative approach. Finally, rarely used drugs appeared safer in FAERS, but this is likely due to underreporting.

1. Kaytser V, et al. Estimating the Probability of Reported Versus Theoretical Drug-Drug Interactions in Headaches Medicine. AL01, IHC 2021, 8–12 September.
2. American Headache Society. Headache. 2019;59(1):1-18.
3. Szperka CL, et al. Headache. 2020;60(5):833–42.

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Posted on 8 November 202118 March 2024