Modelling and assessing one- and two-drug dose titrations.

In health-care, there is a need to quantify medical errors. Among these errors, we observe wrong dose prescriptions. Drug dose titration (DT) is the process by which dosage is progressively adjusted to the patient till a steady dose is reached. Depending on the clinical disease, drug, and patient condition, dose titration can follow different procedures. Once modeled, these procedures can serve for clinical homogenization, standardization, decision support and retrospective analysis. Here, we propose a language to model dose titration procedures. The language was used to formalize one- and two-drug titration of chronic and acute cases, and to perform retrospective analysis of the drug titration processes on 253 patients diagnosed of diabetes mellitus type 2 and treated with metformin, 321 patients treated of chonic heart failure with furosemide, 155 patients with hyperuricemia treated with allopurinol as initial drug and febuxostat as alternative drug, and 187 hyperuricemia patients with primary drug allopurinol and supplementary drug probenecid, in order to identify different types of drug titration deviations from standard DT methods.

Clinical profile of cutaneous adverse drug reactions: a retrospective study of 1883 hospitalized patients from 2007 to 2016 in Shanghai, China.

BACKGROUND: Cutaneous adverse drug reactions (CADRs) are drug-induced skin reactions with or without systemic involvement, ranging from mild maculopapular exanthema (MPE) to life-threatening severe CADRs (S-CADRs). Due to their unpredictability and severity, early recognition of suspected causative drugs is highly recommended. However, the profile of CADRs remains unknown in China. OBJECTIVES: To assess the clinical profile, predominant causative drugs, and cost associated with CADRs in Shanghai, China. MATERIALS AND METHODS: Clinical records of inpatients admitted with a diagnosis of CADRs to the dermatology ward of Huashan Hospital from January 2007 to December 2016 were retrospectively studied. RESULTS: A total of 1,883 patients (1,231 female and 652 male), admitted with a diagnosis of CADR, were investigated. S-CADRs made up 21.99% of all cases (n=414), and urticaria (27.19%) was the most frequent reaction. Of the patients, 53.43% suffered from multiple drug-induced drug eruptions and the rest (45.83%) from single drug-induced drug eruptions. Overall, antimicrobials (28.85%) was the main drug group involved, and for S-CADRs, this was antiepileptic drugs (36.15%). The total cost for CADRs was RMB23,718,788.83 ($3,588,319.04). Both age and sex were related to admission cost (p=0.005 and p=7.84E-8, respectively). Antimicrobials were the most common treatment causing CADRs. CONCLUSION: The management of CADRs requires considerable medical cost. CADRs are not only a health problem but also a significant financial burden for affected individuals.

Retrospective study of 213 cases of Stevens-Johnson syndrome and toxic epidermal necrolysis from China.

BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but severe adverse drug reactions with high mortality. The use of corticosteroids and the management of complications (e.g. infection) in SJS/TEN remains controversial. METHODS: A retrospective study was performed among 213 patients with SJS/TEN who were hospitalized in our department between 2008 and 2018, to investigate the causative agents, clinical characteristics, complications, and prognoses of SJS/TEN mainly treated by systemic corticosteroids combined with intravenous immunoglobulin (IVIG). RESULTS: The causative drugs of SJS/TEN in these patients mainly consisted of antibiotics (61/213, 28.6%), anticonvulsants (52/213, 24.4%), and nonsteroidal anti-inflammation drugs (24/213, 11.3%), among which carbamazepine was the most frequently administered drug (39/213, 18.3%). There were significant differences in the maximum dosage, time to corticosteroid tapering, and the total dosage of corticosteroid between the SJS group and the TEN group, as well as among the three groups (P = 0.000), whereas in the initial dose of corticosteroid was not statistically significant among the three groups (P = 0.277). In a series of 213 cases, 18.4 cases (8.6%) were expected to die based on the score for the toxic epidermal necrolysis (SCORTEN) system, whereas eight deaths (3.8%) were observed; the difference was not statistically significant (P = 0.067; SMR = 0.43, 95% CI: 0.06, 0.48). The most common complications were electrolyte disturbance (174/213, 81.7%), drug-induced liver injury (64/213, 30.0%), infection (53/213, 24.9%), and fasting blood sugar above 10 mmol/L (33/213, 15.5%). Respiratory system (22/213, 10.3%) and wound (11/213, 5.2%) were the most common sites of infection. Multivariate logistic regression analysis indicated that the maximum blood sugar (≥10 mmol/L), the time to corticosteroid tapering (≥12 d), the maximum dosage of corticosteroid (≥1.5 mg/kg/d), and the total body surface area (TBSA) (≥10%) were defined as the most relevant factors of the infection. CONCLUSION: The mortality of patients in this study was lower than that predicted by SCORTEN, although there was no significant difference between them. Hyperglycemia, high-dose corticosteroid, and the TBSA were closely related to the infections of patients with SJS/TEN.

Trends in culprit drugs and clinical entities in cutaneous adverse drug reactions: a retrospective study.

PURPOSE: Morbidity due to cutaneous adverse drug reactions (CADRs) is quite common. The specific culprit drugs change over time and clinicians must be kept informed with updated knowledge, thus preventing potential CADRs. This retrospective study is a survey of CADRs encountered in a hospital-based population in Southern China during three time intervals, from 1984 to 2015. MATERIALS AND METHODS: The clinical records were review of 306 patients with CADRs who were admitted to our hospital from 2011 to 2015. These data were compared with patients visiting our hospital during 1984-1994 and 2003-2010. RESULTS: From 2011 to 2015, the most common CADRs were exanthematous reactions (40.8%) and Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN; 17.0%). There were eight cases (2.6%) of CADRs related to targeted therapy in oncology. In the 205 CADR cases that were due to single medications, the most common offending drugs were allopurinol (21.5%), cephalosporins (10.7%) and carbamazepine (10.2%). The percentages of CADR cases due to allopurinol, carbamazepine, or epidermal growth factor receptor inhibitors were significantly higher from 2011 to 2015 compared with 1984-1994 or 2003-2010. The rate of SJS/TEN occurrence was significantly higher in the two recent periods compared with 1984-1994. CONCLUSIONS: Changes in drug prescriptions are a major factor that affects the CADRs seen in clinical records. Newer drugs can be culpable for CADRs, and more CADRs are now documented with increased severity at clinical presentation. Reliable screening tests for specific drugs are urgently required to eliminate possible fatalities.

Steven Johnson Syndrome and Toxic Epidermal Necrolysis in a burn unit: A 15-year experience.

INTRODUCTION: The diffuse epidermal exfoliation seen in Steven Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) is similar to skin loss in second degree burns, and many of these patients are referred for treatment at burn centers. Treatment can differ markedly from center to center, and mortality can range from 25% to 70%, including a considerable morbidity. However, our experience over a 15-year period from 2000 to 2015 with 40 patients found a mortality rate of only 10% (4/40). The purpose of this paper is to discuss our treatment algorithm as a model for other centers treating SJS/TENs patients. METHODS: Records were reviewed for all patients admitted to the LAC+USC burn unit between 2000 and 2015 and 40 patients were identified with biopsy-proven SJS or TENS. These cases were reviewed for age, gender, initial and greatest TBSA, causative drug, pre-existing medical conditions, and morbidity and mortality. All data were entered into the SPSS statistical software package and all statistical analyses were performed using this program. RESULTS: Our treatment algorithm focused on early referral to a specialty burn unit, immediate discontinuation of the offending drug, fluid resuscitation, nutritional supplementation, and meticulous wound care. Average time to transfer to a burn unit was 3.36 days. Silver-releasing antimicrobial dressings were applied to the affected skin surface and changed every 3 days. Mupirocin coated petroleum gauze was used for facial involvement. Steroids were tapered and discontinued if initiated at an outside facility (58% of patients), and starting after 2001, all patients received a course of IVIG. All patients received fluid resuscitation and the majority received supplemental tube feedings (69%). Average length of total stay was 17.1 days and length of ICU stay 15.9 days. While 44% were transferred to another facility for further rehabilitative care, 37% of patients discharge to home. In patients discharged home with complete resolution of skin lesions, time to healing was an average of 14 days. DISCUSSION: With our 10% mortality rate in 40 patients, our study represents a relatively large study population while maintaining a relatively low mortality rate. The demographic data from our study largely aligns with the existing literature, and we therefore feel that our low mortality rate is due to our treatment algorithm, rather than to a less severe pathology in our patient population. This claim is supported by a standard mortality ratio of 1.68. This ratio proves a significantly improved mortality than would be expected based on disease severity on admission.

Clinical features of and genetic predisposition to drug-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in a single Korean tertiary institution patients-investigating the relation between the HLA -B*4403 allele and lamotrigine.

PURPOSE: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but fatal adverse mucocutaneous reactions to certain drugs. Recent studies suggest that ethnicity and genetic predisposition may play a crucial role in the manifestation of the reaction. In this study, we described the role of human leukocyte antigen (HLA)-B alleles in the development of clinical characteristics and treatment outcomes of SJS/TEN in a single Korean tertiary hospital. METHODS: We retrospectively reviewed the medical records (from March 1, 2010 to February 28, 2014) of 30 patients diagnosed with SJS and/or TEN. RESULTS: The main causative drugs were anticonvulsants (26.7 %) and allopurinol (26.7 %), followed by antibiotics (16.7 %), acetazolamide (10.0 %), acetaminophen (10.0 %), and herbal medication (6.7 %). The mean latencies of these drugs were variable. Liver damage was the most common symptom (observed in 63.3 % of the patients). Of the five patients with lamotrigine-induced SJS/TEN, three expressed the HLA-B*4403 allele (60.0 %). Of the seven patients with allopurinol-induced SJS/TEN, five expressed the HLA-B*5801 allele (71.4 %). CONCLUSIONS: The major SJS/TEN-inducing drugs were found to be allopurinol and anticonvulsants (such as lamotrigine). We speculated that Korean individuals expressing the HLA-B*4403 allele may be highly susceptible to lamotrigine-induced SJS/TEN.

Understanding the dose-response relationship of allopurinol: predicting the optimal dosage.

AIMS: The aim of the study was to identify and quantify factors that control the plasma concentrations of urate during allopurinol treatment and to predict optimal doses of allopurinol. METHODS: Plasma concentrations of urate and creatinine (112 samples, 46 patients) before and during treatment with various doses of allopurinol (50-600 mg daily) were monitored. Non-linear and multiple linear regression equations were used to examine the relationships between allopurinol dose (D), creatinine clearance (CLcr) and plasma concentrations of urate before (UP) and during treatment with allopurinol (UT). RESULTS: Plasma concentrations of urate achieved during allopurinol therapy were dependent on the daily dose of allopurinol and the plasma concentration of urate pre-treatment. The non-linear equation: UT = (1 - D/(ID50 + D)) × (UP - UR) + UR , fitted the data well (r(2) = 0.74, P < 0.0001). The parameters and their best fit values were: daily dose of allopurinol reducing the inhibitable plasma urate by 50% (ID50 = 226 mg, 95% CI 167, 303 mg), apparent resistant plasma urate (UR = 0.20 mmol l(-1), 95 % CI 0.14, 0.25 mmol l(-1)). Incorporation of CLcr did not significantly improve the fit (P = 0.09). CONCLUSIONS: A high baseline plasma urate concentration requires a high dose of allopurinol to reduce plasma urate below recommended concentrations. This dose is dependent on only the pre-treatment plasma urate concentration and is not influenced by CLcr .

Clinical study on treatment of hyperuricaemia by retention enema of Chinese herbal medicine combined with allopurinol.

OBJECTIVE: To study the effect of retention enema of Chinese herbal medicine combined with allopurinol in treating hyperuricaemia (HUE). METHODS: Seventy-eight patients with HUE were assigned to two: groups, the 40 patients in the treated group were treated with retention enema of Chinese herbal medicine combined with oral intake of allopurinol, and the 38 patients in the control group were treated with allopurinol alone. The therapeutic course for all was 6 weeks. The clinical efficacy, changes of symptoms, blood levels of uric acid and lipids, renal function, and 24 h urinary micro-albumin were observed. RESULTS: The total effective rate was: 92.5% in the treated group, which was significantly higher than that in the control group (68.4%, P<0.05). After treatment, the score of symptoms in the treated group decreased from 9.43+/-1.15 scores to 3.25+/-0.85 scores, significantly lower than that in the control group (9.75+/-1.43 scores vs 9.25+/-0.82 scores, P<0.01). Moreover, the post-treatment improvements in blood uric acid, blood lipids, renal function and 24h urinary micro-albumin in the treated group were all better than those in the control group (P<0.05 or P<0.01). CONCLUSION: Retention enema with: Chinese herbal medicine combined with allopurinol could obviously reduce the uric acid level in blood, improve patients' renal function and lipid metabolism, and alleviate the clinical symptoms in patients with HUE.

Febuxostat compared with allopurinol in patients with hyperuricemia and gout.

BACKGROUND: Febuxostat, a novel nonpurine selective inhibitor of xanthine oxidase, is a potential alternative to allopurinol for patients with hyperuricemia and gout. METHODS: We randomly assigned 762 patients with gout and with serum urate concentrations of at least 8.0 mg per deciliter (480 micromol per liter) to receive either febuxostat (80 mg or 120 mg) or allopurinol (300 mg) once daily for 52 weeks; 760 received the study drug. Prophylaxis against gout flares with naproxen or colchicine was provided during weeks 1 through 8. The primary end point was a serum urate concentration of less than 6.0 mg per deciliter (360 micromol per liter) at the last three monthly measurements. The secondary end points included reduction in the incidence of gout flares and in tophus area. RESULTS: The primary end point was reached in 53 percent of patients receiving 80 mg of febuxostat, 62 percent of those receiving 120 mg of febuxostat, and 21 percent of those receiving allopurinol (P<0.001 for the comparison of each febuxostat group with the allopurinol group). Although the incidence of gout flares diminished with continued treatment, the overall incidence during weeks 9 through 52 was similar in all groups: 64 percent of patients receiving 80 mg of febuxostat, 70 percent of those receiving 120 mg of febuxostat, and 64 percent of those receiving allopurinol (P=0.99 for 80 mg of febuxostat vs. allopurinol; P=0.23 for 120 mg of febuxostat vs. allopurinol). The median reduction in tophus area was 83 percent in patients receiving 80 mg of febuxostat and 66 percent in those receiving 120 mg of febuxostat, as compared with 50 percent in those receiving allopurinol (P=0.08 for 80 mg of febuxostat vs. allopurinol; P=0.16 for 120 mg of febuxostat vs. allopurinol). More patients in the high-dose febuxostat group than in the allopurinol group (P=0.003) or the low-dose febuxostat group discontinued the study. Four of the 507 patients in the two febuxostat groups (0.8 percent) and none of the 253 patients in the allopurinol group died; all deaths were from causes that the investigators (while still blinded to treatment) judged to be unrelated to the study drugs (P=0.31 for the comparison between the combined febuxostat groups and the allopurinol group). CONCLUSIONS: Febuxostat, at a daily dose of 80 mg or 120 mg, was more effective than allopurinol at the commonly used fixed daily dose of 300 mg in lowering serum urate. Similar reductions in gout flares and tophus area occurred in all treatment groups.

[Drug-induced urinary calculi in 1999]. / Les lithiases urinaires médicamenteuses en 1999.

Drug-induced urolithiasis are observed in 1.6% of the urinary calculi in France. Drugs crystals are identified in two thirds of these stones. Other drugs are responsible for stones which have an apparent metabolic origin (one third of the cases). Stone analysis using physical methods such as infrared spectroscopy is needed to unambiguously identify stones containing drugs. The inquiry is an important step to identify lithogenetic drugs which do not crystallize in the stones. The main substances which were identified in stones over the past decade were indinavir monohydrate (31.4%), triamterene (11.1%), sulphonamides (10.5%) and amorphous silica (4.5%). The main drugs involved in the nucleation and growth of metabolic stones were calcium and vitamin D supplementation (15%) and long-term treatment with carbonic anhydrase inhibitors (8%). Stone prevention is based on drug withdrawal or change in dosage with additional measures including an increase of diuresis and, if necessary, changes in the urine pH.

Efectos del Allopurinol sobre el riñón: su relación con los radicales libres del oxígeno / Effect of allopurinol over the kidney: oxygen free radical relation

Para dilucidar los mecanismos tóxicos responsables de la nefrotoxicidad inducida por el Allopurinol y las respuestas protectoras endógenas, se investigaron las variaciones de la Creatinina plasmática, la peroxidación lipídica renal, los factores de producción de radicales libres del O2: xantina oxidasa y sus sustratos: xantina e hipoxantina y los factores de eliminación de tales radicales: superóxido dismutasa y catalasa. Las ratas recibieron subcutáneamente inyecciones de Allopurinol en dosis de 100 mg/kg de peso, por día y durante tres días. Comparando ratas normales, se observaron los siguientes cambios: a) un aumento en las proporciones de creatinina plasmática y en los niveles tisulares de la catalasa y de la supeóxido dismutasa; c) los valores máximos y mínimos se observaron al tercer día de administración de la droga y posteriormente todos los parámetros se normalizan a sus niveles originales; d) estos resultados sugieren que la nefrotoxicidad del Allopurinol se atribuiría al aumento de la peroxidación lipídica, que por un lado, aumenta la producción de radicales libres del O2, y por otro lado, estarían dismunuidos los mecanismos de su eliminación

Efectos del Allopurinol sobre el riñón: su relación con los radicales libres del oxígeno / Effect of allopurinol over the kidney: oxygen free radical relation

Para dilucidar los mecanismos tóxicos responsables de la nefrotoxicidad inducida por el Allopurinol y las respuestas protectoras endógenas, se investigaron las variaciones de la Creatinina plasmática, la peroxidación lipídica renal, los factores de producción de radicales libres del O2: xantina oxidasa y sus sustratos: xantina e hipoxantina y los factores de eliminación de tales radicales: superóxido dismutasa y catalasa. Las ratas recibieron subcutáneamente inyecciones de Allopurinol en dosis de 100 mg/kg de peso, por día y durante tres días. Comparando ratas normales, se observaron los siguientes cambios: a) un aumento en las proporciones de creatinina plasmática y en los niveles tisulares de la catalasa y de la supeóxido dismutasa; c) los valores máximos y mínimos se observaron al tercer día de administración de la droga y posteriormente todos los parámetros se normalizan a sus niveles originales; d) estos resultados sugieren que la nefrotoxicidad del Allopurinol se atribuiría al aumento de la peroxidación lipídica, que por un lado, aumenta la producción de radicales libres del O2, y por otro lado, estarían dismunuidos los mecanismos de su eliminación (AU)

Plasma exchange (PE) treatment in drug-induced toxic epidermal necrolysis (TEN).

Toxic epidermal necrolysis (TEN) or Lyell's syndrome is a rare fulminating skin disease notorious for its rapidly progressive course and high mortality rate. TEN is characterized by the sudden onset of epithelial necrosis of skin with frequently associated involvement of the gastrointestinal, genitourinary tract and bronchopulmonary linings. We describe the clinical course of five patients with severe drug-induced TEN, treated with PE. The suspected drugs were carbamazepine in one patient, paracetamol in one, a combination of paracetamol and mefenamic acid in one, allopurinol in one and ciprofloxacin in one. Three had a skin involvement affecting almost the entire surface of the body. In addition to the skin lesions, mouth, esophagus and lungs were also involved. Steroids proved ineffective. PE was carried out because of the rapid deterioration of the clinical picture. The mean number of PE sessions was 3.22 (range 1-5). Complete remission of the syndrome was achieved in four patients. One patient died due to septic shock. As so far there is no treatment of proven value for this condition, controlled trials should be set up in order to assess the value of PE in TEN.

Concomitant administration of 4-hydroxypyrazolopyrimidine (allopurinol) and high-dose continuous infusion 5-fluorouracil.

We tried to study the protection of allopurinol (HPP) from the toxicity of 5-fluorouracil (5-FU). A total of 29 patients received 74 cycles of chemotherapy (16 colon adenocarcinomas, 7 head and neck, 3 breast cancers and 3 cancers of pancreas). HPP was given 900 mg/day p.o. 4 days prior to treatment, and continued with same dose throughout the course of 5-FU and for 12 days after completion of the treatment. 5-FU was administered in 24 hour intravenous infusions on days 1-5 (dose range 900-1,200 mg/m2/day). 5-FU was given alone or in combination with mitomycin-C 10 mg/m2/day (1st day), epirubicin 40 mg/m2/day (1st, 2nd day), cis-platinum 120 mg/m2/day (1st day). In comparison with other studies the toxicity was limited. We conclude that HPP can diminish the side effects, especially myelosuppression, allowing an increase in the maximum tolerated dose of 5-FU; even if combined with other cytostatic drugs. Control studies must be done to confirm our observations.

Xanthine lithiasis, nephrocalcinosis, and renal failure in a leukemia patient treated with allopurinol.

An 11-year-old boy who presented in acute renal failure with significant increases of uric acid and phosphorus in his serum was discovered to have acute lymphoblastic leukemia. Five years later, he had a second and similar episode of acute renal failure, which was responsive to hemodialysis. After three months of daily therapy with allopurinol, a third and final episode of renal failure was unresponsive to peritoneal dialysis. Autopsy revealed an obstructive uropathy; focal nephrocalcinosis; and multiple, small, tan calculi in the calyces of both kidneys. Systemic cryptococcosis was also discovered. The stones, characterized by paper chromatography, electrophoresis, x-ray diffraction, and infrared spectroscopy, were 82% xanthine, 15% oxypurinol, and 3% hypoxanthine. We suggest that attention to the effects of accelerated tumor-cell lysis may protect renal function in patients with a large and drug-sensitive tumor cell load. Similarly, early detection of the fungal complications of leukemic therapy is an essential component of the treatment program.

Photosensitizing drugs and their possible role in enhancing ocular toxicity. Parker Heath memorial lecture.

During the past decade there has been a considerable resurgence of interest in the photochemical effects of ultraviolet radiation capable of penetrating through the cornea (300-400 nm), on the intraocular tissues. The ocular lens and retina have received the most attention. The last few decades have also witnessed the development of a new therapeutic regimen, namely photosensitizing (phototherapy), in which the patients are given known photosensitizing agents and exposed to nonionizing radiation (ultraviolet, and on occasion, visible radiation). Such therapy has caused some ocular side effects, which in most cases could have been prevented. Drugs that are known photosensitizers and are capable of intraocular penetration through the blood-aqueous and blood-retina barrier are discussed with respect to their known or potential photosensitizing and/or phototoxic effects on intraocular tissues.