Psychopharmacology (2011) 214:933–939 pressure, and oxygen (O2) saturation were measured with a Philips C3 Patient Monitor and core temperature with an ingested monitor (Minimitter Vitalsense) at baseline and 0.25, 0.5, 0.75, 1, 2, and 4 h post-dose. Plasma samples for SA levels were obtained at 20 min, and all of the urine was collected for the 4 h post-dose. Assay for salvinorin A and B A sensitive and specific liquid-chromatographic-atmospheric pressure chemical ionization-tandem mass spectrometric (LC-APCI-MS/MS) method was developed to measure SA and its primary metabolite, SB, in human plasma and urine (see Appendix). The C-4 trideuteromethyl ester analogs of the analytes were utilized as the internal standards. The limits of quantitation were 0.5 ng/mL for both SA and SB in plasma and urine. Visual Analog Scales Two VAS questionnaires, anchored with “not at all” to “extremely,” were obtained. One questionnaire (“any drug effect,” “good drug effect,” “bad drug effect,” “high,” “stimulated,” “clear-headed,” “sedat- ed,” “confused,” “drunken,” “insightful,” “closeness to others,” and “intoxication”) was obtained at the same times as physiological measures. The second questionnaire (“Feelings of unreality,” “Difficulty controlling thoughts,” “Size, depth, or shape of my surroundings seems changed,” “My body or body parts seem changed,” “The passing of time seems changed,” “Familiar things seem unfamiliar,” “Some events, objects, or other people have new meanings for me,” “Suspicious feelings that others might be against me,” “When I close my eyes, I see complex abstract patterns,” “When I close my eyes, I see objects or non- living things,” “When I close my eyes, I see animals, people, or beings,” and “When I close my eyes, I see places or landscapes”) was obtained 2 h post-dose with subjects answering for the time since dosing. During screening, subjects were asked to rate their “typical” SA experience on both VAS questionnaires. The Subjective Drug Effects Questionnaire (SDEQ), Altered States of Consciousness Questionnaire (APZ-OAV), and Positive and Negative Affect Schedule (PANAS) were administered between 2 and 4 h post-dose to broadly characterize subjective symptoms typically altered by hallucinogens. The SDEQ is a 272-item drug effects questionnaire that was originally developed to distinguish LSD from D-amphetamine and has subsequently been used to characterize a variety of drug classes (Harris et al. 2002; Katz et al. 1968; Snyder et al. 1968; Turek et al. 1974). The APZ-OAV is a 94-item questionnaire widely used in European studies of hallucinogen-like compounds (Dittrich 1998). The 20-item PANAS is widely used in psychological and pharmacological studies to measure positive and negative affect (Watson et al. 1988). 935 Results Eight subjects (5 Caucasian men, 1 Caucasian woman, 1 Asian man, and 1 Asian woman) with an average age of 31 years (range, 21–45) received SA in this study. Subjects reported a mean of 10 (range, 3–40) previous uses of SD and reported experiencing “strong effects” an average of six times (range, 2–20). One subject reported using SD in the 90 days before study entry, and two more reported using it in the year before study entry. Therefore, tolerance to SA among our subjects was unlikely. All subjects reported abstinence from prescribed or recreational opiate agonists for at least 90 days before study entry. Because no subject met the stopping criteria, each subject was given all dose levels of SA. SA did not affect pulse, blood pressure, O2 saturation, or core temperature. In general, no subjects reported effects similar in quality or magnitude to their reported “typical” SA exposures. There was no effect of dose on responses to the SDEQ, APZ-OAV, PANAS, or most VAS items. VAS scores for “headache” and “insightful” items decreased relative to placebo, but effects were small and inconsistent between doses. Only two male subjects reported VAS “intoxication” scores above 25: both occurred 15 min after the 1,000 μg dose. In contrast, subject’s ratings of “typical” SA experiences using the VAS (Fig. 1) and APZ-OAV measures were significantly different from, and, in general, higher than, ratings for both placebo and the 4,000 μg dose. Because of the low intoxication ratings reported, we only assayed blood and urine samples from the highest (4,000 μg) dose and the two cases where intoxication scores were higher than 25. Most SA concentrations were below the limit of quanti- fication (Table 1). Discussion Sublingual doses of 4,000 μg SA did not produce even mild effects. Scores on the VAS and APZ-OAV measures indicated that the subjective experience of 4,000 μg failed to differ significantly from placebo and was significantly lower than scores for “typical” effects. The lack of subjective effects and the low levels of SA in blood and urine suggest that the sublingual bioavailability of SA is poor. This is consistent with earlier anecdotal reports that sublingual doses of up to 2 mg (Siebert 1994) or 12 mg (Zhah 2009) produced no consistent effect, and cast doubt on claims of detectable effects at doses as low as 100 μg (Ott 1995). One possible factor in these discrepancies is the different solvents used. We used 25% DMSO/PEG-400, while earlier reports have employed ethanol (Siebert 1994), DMSO (Ott