Table 1.

Comparator overview of some of the major properties of mephedrone and MDMA

Behavioural measurements	Mephedrone	MDMA
Locomotor activity(1–3)2010
• Duration	↑	↑↑
• Magnitude	↑	↑
• 5-HT syndrome	✓	✓
• Sensitization to same drug	✓	✓
Body temperature(4–6)2010
• Singly housed	↓	↓↓
• Group housed	↔	↑↑
• High-ambient temperature	↔↑§2010	↑↑↑
Drug self-administration(6)2010	↑↑↑	↑
Chemical measurements
Pharmacokinetics(7,8)
• Plasma half-life (h)	∼0.4	∼0.8
• Half-life similar to humans	✓	Χ
• Active metabolites	?	✓
• Brain penetration	↑↑	↑
Brain monoamine release in vivo(9–11)2010
• 5-HT	↑↑↑	↑↑↑
• Dopamine	↑↑	↑
Brain monoamine content at 60 min(12–13)
• 5-HT	↓	↓↓↓
• Dopamine	↑	↑
Brain neurotoxicity(14–16)2010
• 5-HT in rats	?*2010	✓
• Dopamine in mice	–	✓
Monoamine uptake inhibition (IC50)(18,19)
• SERT	422	125
• DAT	762	1009
• NET	487	450
Monoamine release (EC50)(20–22)2010
• SERT	122	39
• DAT	51	42
• NET	58	53

Data compiled to compare the behavioural effects and pharmacokinetic measurements were derived from studies using a single acute s.c. or i.p. injection of either drug (typically 1–10 mg·kg⁻¹ but up to 30 mg·kg⁻¹ for mephedrone) in rats and where available in mice, but in some microdialysis studies i.v. administration was used. Studies examining a neurotoxic effect have used multiple doses (either on the same day or over a few weeks) typically administering 10–30 mg·kg⁻¹ s.c. or i.p. Arrows show relative size of behavioural response, either increase (↑) or decrease (↓), ↔ indicates no significant change from control. Check mark (✓) shows that a response or change occurs, dash (−) means change not seen, and X means the value is different from humans. IC₅₀ and EC₅₀ values are both reported in nM and taken from Baumann et al. (2013a).

^*Indicates that one of five studies reported neurotoxic damage. Combinations of other drugs with either MDMA or mephedrone and have been reported to, respectively, enhance or induce toxicity as detailed in the text.

^§Indicates conflicting results. Key references supporting the synopsis for each parameter are indicated as a numerical superscript and below, but further references are provided in the relevant section of the review: ¹Kehr et al. (2011), ²Lisek et al. (2012), ³Green et al. (2003), ⁴Shortall et al. (2013a, b,), ⁵Miller et al. (2013), ⁶Docherty and Green (2010), ⁷Baumann et al. (2009), ⁸Martínez-Clemente et al. (2013), ⁹Kehr et al. (2011), ¹⁰Wright et al. (2012a), ¹¹O'Shea et al. (2005), ¹²Motbey et al. (2012a), ¹³Colado and Green (1994), ¹⁴Shortall et al. (2013a, c,), ¹⁵Motbey et al. (2012a), ¹⁶Green et al. (2003), ¹⁷Hadlock et al. (2011), ¹⁸Martínez-Clemente et al. (2012), ¹⁹Baumann et al. (2013a), ²⁰Nagai et al. (2007), ²¹Baumann et al. (2011), ²²Simmler et al. (2013).