Pharmacokinetic properties of 4‐fluoroamphetamine in serum and oral fluid after oral ingestion
Stefan W. Toennes, David J. Schneider, Werner Pogoda, Alexander Paulke, Cora Wunder, Eef L. Theunissen, Kim P. C. Kuypers, Eliza de Sousa Fernandes Perna, Johannes G. Ramaekers
Drug Testing and Analysis March 26, 2019 DOI: 10.1002/dta.2595 via OpenAlex
Summary
The pharmacokinetics of 4-fluoroamphetamine (4-FA) in humans resemble those of amphetamine, with peak serum concentrations occurring about 2 hours after ingestion and an elimination half-life of roughly 8-9 hours, though this varies widely (5.5-16.8 hours). After a 100 mg dose, median maximum serum concentration was 195 ng/mL (range 155-316 ng/mL). Concentrations in oral fluid were higher than in serum, especially during the first 3 hours, likely due to oral contamination. Serum concentrations observed in forensic cases matched those in the study, suggesting recreational doses are similar, but such doses may already cause prominent adverse effects and life-threatening consequences.
Study at a glance
| Characteristics | Controlled study Peer reviewed |
|---|---|
| Sample size | 12 |
| Population | Humans |
| Intervention | 4-fluoroamphetamine |
| Dose | 100 mg and 150 mg |
| Duration | 12 hours |
| Keywords | Ingestion Dose Pharmacokinetics Amphetamine Oral administration |
| Citations | 9 |
| Key finding | The pharmacokinetic properties of 4-FA are similar to those of amphetamine, with a marked variation in elimination half-life and peak serum concentrations around 2 hours after ingestion. |
Abstract
INTRODUCTION: Each year, synthetic drugs occur in high numbers on the illicit drug market. But data on their pharmacology and toxicology are scarce. Therefore, a controlled study was performed to evaluate pharmacokinetic parameters of 4-fluoroamphetamine (4-FA) in humans and to compare it with effects. METHODS: Twelve subjects ingested 100 mg and five subjects also received 150 mg 4-FA in a bitter lemon drink. Blood and oral fluid samples were taken during the following 12 hours and analyzed for 4-FA and traces of amphetamine as impurity by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: For 12 hours after ingestion, the concentration-time course of 4-FA was similar to that of amphetamine with maximal concentrations appearing in serum after about 2 hours (in median 195 ng/mL after the 100 mg dose, range 155-316 ng/mL). The elimination half-life was approximately 8-9 hours and shorter than that of amphetamine but it exhibited a marked variation (5.5-16.8 hours). In oral fluid, 4-FA could also be detected for 12 hours and concentrations were higher than in serum. During the first 3 hours after ingestion concentrations were higher, most probably due to oral contamination. Serum concentrations in forensic cases were in the range of those observed in the present study suggesting dosages in recreational use in the range of those tested here. CONCLUSIONS: The pharmacokinetic properties of 4-FA are similar to that of amphetamine including a marked variation in elimination. However, recreational dosages may already exhibit prominent adverse effects and may even have life-threatening consequences.