Diclofenac metabolic profile following in vitro percutaneous absorption through viable human skin.

The extent of metabolism of diclofenac sodium in excised viable human skin was investigated using combination HPLC and radioactivity assay. In an earlier diffusion experiment using an in vitro flow-through diffusion system, radiolabelled diclofenac sodium in either lotion (Pennsaid) or aqueous solution was applied to viable human skin, either as single dose or multiple dose (8 times over 2 days). In this study, the receptor fluid samples from the diffusion experiment were subjected to extraction and the aliquot was analysed using HPLC to separate diclofenac and authentic metabolites. Based on the radioactivity of each HPLC fraction, the collection time of the fractions was compared with the retention time of diclofenac and metabolites in standard solutions. The samples from a single or multiple dose application of lotion showed radioactivity in mainly one fraction, whose retention time corresponded with diclofenac. Other HPLC fractions showed none or only small amounts of radioactivity within the error range of the assay. The same results were obtained with the pooled samples from the application of the lotion or of aqueous solution. The results suggest that diclofenac sodium does not undergo metabolism in viable human epidermis during percutaneous absorption in vitro. Hence, with topical application to human skin in vivo, diclofenac will be delivered with minimal, if any, metabolism.     

Glomerulonephritis associated with polymyositis.

Five patients with primary idiopathic polymyositis developed proteinuria associated with urine sediment abnormalities. Renal biopsies disclosed a focal mesangial proliferative glomerulonephritis with deposits of immunoglobulin and complement. After treatment of the polymyositis with corticosteroids, proteinuria and urine sediment changes disappeared within 4 to 8 wk along with an improvement in the muscle disease. Although the pathogenesis remains to be determined, immune complexes may be implicated in the etiology of this renal lesion.     

False-positive amplified Mycobacterium tuberculosis direct test results for samples containing Mycobacterium leprae

Nucleic acid amplification tests are widely used in mycobacteriology laboratories to rapidly detect Mycobacterium tuberculosis complex directly in clinical specimens. A positive result provides an early diagnosis of tuberculosis, allowing initiation of appropriate therapy and public health measures.     

Enhanced human nail drug delivery: nail inner drug content assayed by new unique method.

The purpose of this study was to develop an assay method of the human inner nail plate and to compare nail drug penetration by a penetrating enhancing formulation (the test carrier formulation). The test carrier and saline formulations were tested using radiolabeled urea, ketoconazole, and salicylic acid. After twice dosing daily for 7 days on human nail plates, the under inner section of the nail plate was assayed for absorbed drug content using a unique drilling/removal system. Results show that the weight-normalized radioactivity contents of three chemicals in the inner intermediate nail plate center in the carrier formulation were two fold higher than those from saline (p < 0.05). Total radioactivity recovery of dosed [(14)C]-salicylic acid was 89 +/- 2% in the carrier formulation and 88 +/- 5% in saline. In saline formulation, salicylic acid showed greater binding to the outer nail, making it less bioavailable for the inner nail area. This didn't occur with carrier formulation. In conclusion, topical treatment of nail diseases such as onychomycosis is not yet sufficiently effective, likely because of minimal drug penetration into the inner nail plate where the disease perpetuates. The assay system has the unique characteristic of being able to assay the inner part of the nail where the disease resides.     

One-year outcomes and health care utilization in survivors of severe acute respiratory syndrome

BACKGROUND: Severe Acute Respiratory Syndrome (SARS) became a global epidemic in 2003. Comprehensive information on 1-year outcomes and health care utilization is lacking. Research conducted during the SARS outbreak may help inform research planning for future public health emergencies. The objective of this study was to evaluate the 1-year outcomes in survivors of SARS and their family caregivers. METHOD: The study was prospective and observational. We evaluated 117 SARS survivors from Toronto, Ontario. Patients were interviewed and underwent physical examination, pulmonary function testing, chest radiography, a 6-minute-walk test, quality-of-life measures, and self-report of health care utilization. At 1 year, informal caregivers were identified for a survey on caregiver burden. RESULTS: The enrolled survivors of SARS were young (median age, 42 years), and most were women (67%) and health care workers (65%). At 1 year after hospital discharge, pulmonary function measures were in the normal range, but 18% of patients had a significant reduction in distance walked in 6 minutes. The Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) domains were 0.3 to 1.0 SD below normal at 1 year. Of the patients, 17% had not returned to work by 1 year. Fifty-one patients required 668 visits to psychiatry or psychology practitioners. During the SARS epidemic, informal caregivers reported a decline of 1.6 SD below normal on the mental component score of the SF-36. CONCLUSIONS: Most SARS survivors had good physical recovery from their illness, but some patients and their caregivers reported a significant reduction in mental health 1 year later. Strategies to ameliorate the psychological burden of an epidemic on the patient and family caregiver should be considered as part of future pandemic planning.     

Equivalence study of a topical diclofenac solution (pennsaid) compared with oral diclofenac in symptomatic treatment of osteoarthritis of the knee: a randomized controlled trial

OBJECTIVE:. To compare the safety and efficacy of a topical diclofenac solution versus oral diclofenac in relieving the symptoms of primary osteoarthritis (OA) of the knee, in a randomized, double-blind, double-dummy equivalence trial. METHODS: A total of 622 men and women with radiological evidence of primary knee OA and mild to severe symptoms were randomly assigned to treatment with a topical diclofenac solution plus placebo oral capsules, or placebo topical solution plus oral diclofenac (50 mg) capsules. Patients applied 50 drops of study solution and took 1 study capsule 3 times daily for 12 weeks. Efficacy variables were pain and physical function, measured by the Western Ontario and McMaster Universities (WOMAC) VA 3.1 OA Index, and patient global assessment (PGA). Equivalence in the per-protocol group was based on previously defined ranges of clinically significant difference. Safety was assessed by evaluation of adverse events, vital signs, and laboratory data. RESULTS: The difference in mean (95% CI) change scores (final minus baseline) between treatments was 13.3 mm (-8.6 to 35.2) for pain (total scale 500 mm), 71.0 mm (-2.4 to 144.5) for physical function (total scale 1700 mm), and 4.3 mm (-1.2 to 9.8) for PGA (total scale 100 mm). The CI for each efficacy variable fell within the predefined equivalence ranges (pain, +/- 75 mm; physical function, +/- 255 mm; PGA, +/- 20 mm), indicating that no clinically relevant difference was found between the 2 treatment arms. Safety analyses of patients applying topical diclofenac solution revealed some minor skin irritation at the application site--mostly skin dryness in 83/311 (27%) patients--but a significantly reduced incidence, relative to oral diclofenac, of total and severe gastrointestinal (GI) adverse events, including dyspepsia, abdominal pain, diarrhea, and nausea. The number of patients developing abnormal liver function tests (including clinically significant elevation), hemoglobin, and creatinine clearance was significantly higher in the oral diclofenac group. CONCLUSION: Application of this topical diclofenac solution to the knee of patients with OA produced relief of symptoms equivalent to oral diclofenac, with minor local skin irritation, but significantly reduced incidence of diclofenac-related GI complaints and abnormal laboratory values.     

Topical anesthetics

Topical anesthetics have become valuable tools in the field of dermatology, especially in pediatric patients, who have particular need for such anesthesia. The ideal topical anesthetic should provide effective, painless cutaneous analgesia with quick onset, sufficient duration and minimal adverse effects. This article reviews the basic science concepts relevant to the safe and judicious use of topical anesthetic agents in children, examines the specific characteristics and practical uses of these agents, and discusses the various unique delivery systems currently available.     

In Vivo Bioavailability and Metabolism of Topical Diclofenac Lotion in Human Volunteers

Purpose. The primary objective of this study was to determine the rate and extent of transdermal absorption for systemic delivery of diclofenac from Pennsaid (Dimethaid Research, Inc.) topical lotion into the systemic circulation after the lotion was applied to human volunteers, in an open treatment, non-blinded, non-vehicle controlled study. In addition, the in vivo metabolism of this topical diclofenac lotion has also been studied. Methods. Human volunteers were dosed with topical [¹⁴C]-diclofenac sodium 1.5% lotion on the knee for 24 h. Sequential time blood and urine samples were taken to determine pharmacokinetics, bioavailability and metabolism. Results. Topical absorption was 6.6% of applied dose. Peak plasma ¹⁴C occurred at 30 h after dosing, and peak urinary ¹⁴C excretion was at 24–48 h. The urinary ¹⁴C excretion pattern exhibits more elimination towards 24 h and beyond, as opposed to early urinary ¹⁴C excretion. This suggests a continuous delivery of [¹⁴C]-diclofenac sodium from the lotion into and through skin which only ceased when the dosing site was washed. Skin surface residue at 24 h was 26 ± 9.5% dose (remainder assumed lost to clothing and bedding). Extraction of metabolites from urine amounted to 7.4–22.7% in untreated urine, suggesting substantial diclofenac metabolism to more water soluble metabolites, probably conjugates, which could not be extracted by the method employed. Two Dimensional TLC analysis of untreated urine showed minimal or no diclofenac, again emphasizing the extensive in vivo metabolism of this drug. Treatment of the same urine samples with the enzymes sulfatase and (-glucuronidase showed a substantial increase in the extractable material. Three spots were consistently present in each sample run, namely diclofenac, 3hydroxy diclofenac and an intermediate polar metabolite (probably a hydroxylated metabolite). Therefore, there was significant sulfation and glucuronidation of both diclofenac and numerous hydroxy metabolites of diclofenac, but many of the metabolites/conjugates remain unidentified. Conclusions. There was a continuous delivery of diclofenac sodium from the lotion into and through the skin, which ceased after the dosing site was washed. The majority of the material excreted in the urine were conjugates of hydroxylated metabolites, and not the parent chemical, although further identification is required.     

Allergic contact dermatitis from tacrolimus

A 9-year-old boy developed allergic contact dermatitis from tacrolimus ointment. Tacrolimus was proven to be the allergen by right-versus-left double-blinded provocative use testing of tacrolimus ointment 0.1% versus inactive vehicle applied twice daily to normal preauricular and antecubital skin. Facial dermatitis appeared after 1 week and antecubital dermatitis after 7 weeks. Furthermore, patch testing of each individual ingredient was positive only with tacrolimus; a concentration of 2.5% in ethanol was required. Forty control patients had negative patch tests with tacrolimus 5% in ethanol. We hypothesize that the unusually long time required to elicit a positive use test on the arm and the high patch test concentration required on the back are caused by low percutaneous absorption through normal extrafacial skin. This is likely to be caused in part by the high molecular weight of tacrolimus. A similar phenomenon may occur when patch testing with neomycin sulfate.