Evaluation of Ebola Virus Inhibitors for Drug Repurposing.
Level 5 - mechanism / opinion, no new human data
Preclinical in vitro assays and animal (mouse and guinea pig) infection models.
PubMed 27622822 · doi:10.1021/acsinfecdis.5b00030
What was done
FDA-approved drugs were systematically screened in vitro for antiviral activity against Ebola virus (>50% viral inhibition and <30% toxicity in Vero cells) using replication, entry, and cytotoxicity assays. Based on human pharmacokinetics and safety profiles, seven hits (chloroquine, amiodarone, prochlorperazine, benztropine, azithromycin, chlortetracycline, and clomiphene) were evaluated in vivo via intraperitoneal or oral routes in an Ebola mouse model. Leading candidates were re-tested for reproducibility in mice and further evaluated across a range of doses in a guinea pig Ebola model.
What was found
Initially, azithromycin (100 mg/kg twice daily IP), chloroquine (90 mg/kg twice daily IP), and amiodarone (60 mg/kg twice daily IP) demonstrated significant increases in mouse survival. Upon repeat testing, only chloroquine reproducibly gave significant efficacy in mice. In the guinea pig model, neither chloroquine nor azithromycin increased survival at any tested dose, and drug-related toxicity occurred at lower doses than in mice. Exact survival percentages, effect sizes, and animal numbers were not reported in the abstract.
Why it matters
This study demonstrates the critical friction points in drug repurposing for emerging viruses, proving that in vitro antiviral activity and single-species rodent survival often fail to translate to other animal models due to toxicity and pharmacokinetic differences.
Limits
This is purely preclinical research with no human clinical testing. Sample sizes, quantitative survival rates, and statistical metrics are omitted from the abstract. Mouse efficacy findings failed completely in the guinea pig model.
Cited by
- contradicts The macrolide antibiotic azithromycin exhibits antiviral activity against Ebola virus in animal models.