Safety and Pharmacokinetics of PSD502 in Healthy Chinese Male and Female Volunteers: Two Randomized, Double-Blind, Placebo-Controlled, Phase I Trials.

BACKGROUND AND OBJECTIVE: PSD502 is a metered-dose spray for premature ejaculation. The two trials aimed to evaluate the safety and pharmacokinetics of PSD502 in healthy Chinese male and female individuals. METHODS: Two phase I, randomized, double-blind, placebo-controlled trials were conducted in men (Trial 1) and women (Trial 2). The participants were randomized 3:1 to receive PSD502 (7.5 mg of lidocaine and 2.5 mg of prilocaine per spray) or a placebo. For male individuals, a single dose (three sprays) once daily was applied to the glans penis for 21 days except for nine sprays (three doses) on days 7 and 14, 4 h apart for each dose. For female individuals, two sprays were applied to the vagina and one to the cervix once daily for 7 days. The primary endpoint was safety. Pharmacokinetics analysis was also performed. RESULTS: Twenty-four male and 24 female individuals were recruited. Treatment-emergent adverse events occurred in 38.9% (7/18) of male individuals and 66.7% (12/18) of female individuals in the PSD502 group, respectively. Both trials reported 50.0% (3/6) treatment-emergent adverse events for the placebo. No grade ≥ 3 treatment-emergent adverse events, serious adverse events, or treatment-emergent adverse events leading to early withdrawal or discontinuation occurred. After consecutive applications, lidocaine and prilocaine cleared rapidly in both trials. Plasma concentrations exhibited high inter-individual variability. The maximum plasma concentrations of active ingredients were far below the anticipated minimum toxic concentrations. The area under the plasma concentration-time curve of metabolites were ≤ 20% of the parent drugs. No clinically significant accumulations were observed in the two trials. CONCLUSIONS: PSD502 was well tolerated and showed low plasma concentrations in healthy Chinese male and female individuals.

Poisoning associated with inappropriate use of a eutectic mixture of lidocaine and prilocaine before laser-assisted hair removal: about 3 cases.

BACKGROUND: Eutectic mixtures of lidocaine and prilocaine are used during painful dermatological procedures. Poisoning is rarely reported in adults. MATERIAL AND METHOD: We report three cases of women who experienced lidocaine and prilocaine poisoning after laser-assisted hair removal. Plasma levels of local anesthetics were assayed by a fully validated liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method. CASE REPORTS: The rules of application of the anesthetic cream were observed apart from the maximum dose and/or maximum surface area. One patient applied a higher dose than the maximum recommended dose (140 instead of 60 g) and all patients failed to comply with the maximum recommended surface area (600 cm2). The patients presented an unusual clinical pattern as compared with other local anesthetics overdose: signs of cardiac toxicity with no ECG changes or arrhythmia, neurological toxicity without seizures or coma, and methemoglobinemia. DISCUSSION: Health authorities should publish explicit recommendations targeting users and prescribers with particular emphasis on the maximal surface area of application.