Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: The US Food and Drug Administration (FDA) has provided guidance that sunscreen active ingredients with systemic absorption greater than 0.5 ng/mL or with safety concerns should undergo nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies. Objective: To determine whether the active ingredients (avobenzone, oxybenzone, octocrylene, and ecamsule) of 4 commercially available sunscreens are absorbed into systemic circulation. Design, Setting, and Participants: Randomized clinical trial conducted at a phase 1 clinical pharmacology unit in the United States and enrolling 24 healthy volunteers. Enrollment started in July 2018 and ended in August 2018. Interventions: Participants were randomized to 1 of 4 sunscreens: spray 1 (n = 6 participants), spray 2 (n = 6), a lotion (n = 6), and a cream (n = 6). Two milligrams of sunscreen per 1 cm2 was applied to 75% of body surface area 4 times per day for 4 days, and 30 blood samples were collected over 7 days from each participant. Main Outcomes and Measures: The primary outcome was the maximum plasma concentration of avobenzone. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, and ecamsule. Results: Among 24 participants randomized (mean age, 35.5 [SD, 1.5] years; 12 (50%] women; 14 [58%] black or African American; 14 [58%]), 23 (96%) completed the trial. For avobenzone, geometric mean maximum plasma concentrations were 4.0 ng/mL (coefficient of variation, 6.9%) for spray 1; 3.4 ng/mL (coefficient of variation, 77.3%) for spray 2; 4.3 ng/mL (coefficient of variation, 46.1%) for lotion; and 1.8 ng/mL (coefficient of variation, 32.1%). For oxybenzone, the corresponding values were 209.6 ng/mL (66.8%) for spray 1, 194.9 ng/mL (52.4%) for spray 2, and 169.3 ng/mL (44.5%) for lotion; for octocrylene, 2.9 ng/mL (102%) for spray 1, 7.8 ng/mL (113.3%) for spray 2, 5.7 ng/mL (66.3%) for lotion, and 5.7 ng/mL (47.1%) for cream; and for ecamsule, 1.5 ng/mL (166.1%) for cream. Systemic concentrations greater than 0.5 ng/mL were reached for all 4 products after 4 applications on day 1. The most common adverse event was rash, which developed in 1 participant with each sunscreen. Conclusions and Relevance: In this preliminary study involving healthy volunteers, application of 4 commercially available sunscreens under maximal use conditions resulted in plasma concentrations that exceeded the threshold established by the FDA for potentially waiving some nonclinical toxicology studies for sunscreens. The systemic absorption of sunscreen ingredients supports the need for further studies to determine the clinical significance of these findings. These results do not indicate that individuals should refrain from the use of sunscreen. Trial Registration: ClinicalTrials.gov Identifier: NCT03582215.

Thalidomide use in the US : experience with pregnancy testing in the S.T.E.P.S. programme.

INTRODUCTION: In 1998, thalidomide (Thalomid), a known human teratogen, was approved by the US FDA for the treatment of erythema nodosum leprosum. To prevent fetal exposure to thalidomide, a restricted distribution risk management programme, the System for Thalidomide Education and Prescribing Safety (S.T.E.P.S.), was implemented. All clinicians, pharmacists and patients who prescribe, dispense and receive thalidomide, respectively, are required to enroll in S.T.E.P.S. Sexually active females of childbearing potential must use two methods of birth control before, during and after treatment. These patients must also have a negative pregnancy test within 24 hours before beginning therapy and periodically while on therapy. The objective of this report is to summarise the patterns of thalidomide use and to describe the occurrence of positive pregnancy tests in females of childbearing potential while they were using thalidomide in the S.T.E.P.S. programme in the US. STUDY DESIGN/METHODS: A retrospective review of patients receiving thalidomide within the S.T.E.P.S. programme from September 1998 to 31 December 2004 to determine the occurrence of positive pregnancy tests whilst on treatment. RESULTS: Approximately 124,000 (43% female) patients were registered within the S.T.E.P.S. programme between September 1998 and 31 December 2004. Approximately 6,000 patients were females of childbearing potential, representing 5% of all patients and 11% of all female patients. Between 30 July 2001 and 31 December 2004, >88% of thalidomide use was for oncological conditions. There were 72 females of childbearing potential who had positive pregnancy tests. Sixty-nine of these patients had false positive pregnancy tests. Of the remaining three, one woman was pregnant while on thalidomide. This patient had an initial negative test and received thalidomide. Therapy was stopped when she had a positive pregnancy test. This pregnancy resulted in a miscarriage. Two additional patients were determined to be pregnant before receiving thalidomide. CONCLUSIONS: The S.T.E.P.S. programme is critical to managing the risks of thalidomide-associated teratogenicity. Sustained vigilance among health care providers and patients receiving thalidomide is essential to its continued success. Health care providers should be aware of the occurrence of false-positive pregnancy tests in females of childbearing potential receiving thalidomide.

Ectopic pregnancy risk when contraception fails. A review.

OBJECTIVE: To alert clinicians to the risk of ectopic pregnancy when certain contraceptive methods fail by summarizing data from trials reviewed by the U.S. Food and Drug Administration (FDA). STUDY DESIGN: The review focuses on 7 contraceptive drug products with an increased risk of ectopic pregnancy when the method fails. Data were extracted from reviews of clinical trials submitted to the FDA to support marketing applications and from the medical literature. Data on 6 other contraceptive drug products and published data for tubal ligations are used for comparison. This review does not include medroxyprogesterone acetate injections because the FDA reviews for this method did not include any pregnancy outcome information. RESULTS: The results are presented in a table and are compared to postmarketing surveillance reports and published literature, when available. The proportion of ectopic pregnancies among all pregnancies ranged from 1:2 to 1:21 for intrauterine devices, tubal ligations, progestin-only implants and progestin-only oral contraceptives. Although the confidence intervals for the proportions were large in trials with few pregnancies, both postmarketing surveillance reports and published literature support proportions calculated from clinical trial data. CONCLUSION: Pregnancies in women using progestin-only oral contraceptives, progestin-only implants, intrauterine devices and tubal ligations are more likely to be ectopic than pregnancies in the general population.