Judith P. Kelly

Medication use and the risk of Stevens-Johnson syndrome or toxic epidermal necrolysis.

Background Toxic epidermal necrolysis and Stevens–Johnson syndrome are rare, life-threatening, drug-induced cutaneous reactions. We conducted a case–control study to quantify the risks associated with the use of specific drugs. Methods Data were obtained through surveillance networks in France, Germany, Italy, and Portugal. Drug use before the onset of disease was compared in 245 people who were hospitalized because of toxic epidermal necrolysis or Stevens–Johnson syndrome and 1147 patients hospitalized for other reasons (controls). Crude relative risks were calculated and adjusted for confounding by multivariate methods when numbers were large enough. Results Among drugs usually used for short periods, the risks were increased for trimethoprim–sulfamethoxazole and other sulfonamide antibiotics (crude relative risk, 172; 95 percent confidence interval, 75 to 396), chlormezanone (crude relative risk, 62; 21 to 188), aminopenicillins (multivariate relative risk, 6.7; 2.5 to 18), quinolones (multivariate rel...

Risk of aspirin-associated major upper-gastrointestinal bleeding with enteric-coated or buffered product

BACKGROUND Aspirin products are known to cause irritation and injury to the gastric mucosa. The belief that enteric-coated and buffered varieties are less likely to occasion major upper-gastrointestinal bleeding (UGIB) than plain aspirin was tested in data from a multicentre case-control study. METHODS 550 incident cases of UGIB admitted to hospital with melaena or haematemesis and confirmed by endoscopy, and 1202 controls identified from population census lists, were interviewed about use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) during the 7 days before the onset of bleeding (cases) or interview (controls). Relative risks of UGIB for each type of aspirin used regularly (at least every other day) were calculated overall, and according to dose, by multiple logistic regression, with control for age, sex, marital status, date, education, cigarette smoking, alcohol use, and use of NSAIDs. FINDINGS The relative risks of UGIB for plain, enteric-coated, and buffered aspirin at average daily doses of 325 mg or less were 2.6, 2.7, and 3.1, respectively. At doses greater than 325 mg, the relative risk was 5.8 for plain and 7.0 for buffered aspirin; there were insufficient data to evaluate enteric-coated aspirin at this dose level. There were no important differences in risk attributable to the three aspirin forms according to bleeding site (gastric vs duodenal), or when users of NSAIDs were excluded. INTERPRETATION Use of low doses of enteric-coated or buffered aspirin carries a three-fold increase in the risk of major UGIB. The assumption that these formulations are less harmful than plain aspirin may be mistaken.

Risk of Stevens-Johnson syndrome and toxic epider mal necrolysis during first weeks of antiepileptic therapy: a case-control study

Summary Background There is still controversy about whether all antiepileptic drugs are associated with the severe cutaneous reactions Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). We have studied the role of antiepileptic drugs in SJS and TEN, taking into account potential cofactors that might confound or modify the risk. Methods The case-control study in France, Italy, Germany, and Portugal identified cases of SJS/TEN that developed when the patient was not in hospital and were validated by an expert committee. Controls were patients admitted to the same hospital as the case for an acute illness or an elective procedure. Findings 73 (21%) of the 352 SJS/TEN cases and 28 (2%) of the 1579 controls reported intake of antiepileptic drugs. Among the 73 exposed SJS and TEN patients, 36 reported intake of phenobarbital, 14 of phenytoin, 21 of carbamazepine, 13 of valproic acid, and three of lamotrigine. Risk was highest in the first 8 weeks after onset of treatment. For individual antiepileptic drugs the univariate relative risk of SJS/TEN for 8 weeks or less of use was 57 (95% Cl 16–360; multivariate risk 59 [12–302]) for phenobarbital; 91 (26–∞) for phenytoin; 120 (34–∞) for carbamazepine; 25 (5·6-∞) for lamotrigine, and 24 (5·9-∞) for valproic acid. The result for valproic acid was based on four case users, all of whom reported concurrent use of other associate drugs. The univariate relative risk for more than 8 weeks of use was 6·2 (2·4-17·0; multivariate risk 2·1 [0·5-9·3]) for phenobarbital, 1·2 (0–5·4) for phenytoin, 0·4 (0·02-2·1) for carbamazepine, and 7·0 (2·4-21·0; multivariate risk 2·0 [0·3-15·0]) for valproic acid. Interpretation SJS and TEN are associated with short-term therapy with phenytoin, phenobarbital, and carbamazepine. The association with valproic acid seems to be confounded by concomitant short-term therapy with other causal drugs. Lamotrigine also has the potential for severe skin reactions. The period of increased risk is largely confined to the first 8 weeks of treatment.

Risk of Localized and Widespread Endometrial Cancer in Relation to Recent and Discontinued Use of Conjugated Estrogens

In a case-control study of the risk of adenocarcinoma of the endometrium in relation to conjugated-estrogen use, we found that 31 per cent of 425 women with endometrial cancer and 15 per cent of 792 controls reported having used conjugated estrogens; the rate-ratio estimate was 3.5 with a 95 per cent confidence interval of 2.6 to 4.7. For use that lasted at least one year, the rate-ratio estimate for Stage I or II cancer was 5.2 (95 per cent confidence interval, 3.7 to 7.2), and for Stages III and IV combined it was 3.1 (1.5 to 6.4). Among women who had used estrogen for at least one year and then discontinued it, the risk of endometrial cancer remained significantly elevated even after estrogen-free intervals of over 10 years. The findings suggest that long-term use of conjugated estrogen increases the risk of both localized and widespread endometrial cancer. The data also suggest that women who have taken conjugated estrogen for one or more years remain at increased risk for at least 10 years after they discontinue use. Such women should be considered for long-term gynecologic surveillance.

Medications as Risk Factors of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in Children: A Pooled Analysis

OBJECTIVE. The aim of this study was to determine the relation of medications to the risk of Stevens-Johnson syndrome and toxic epidermal necrolysis in children <15 years of age. METHODS. We conducted a pooled analysis by using data from 2 multicenter international case-control studies: the severe cutaneous adverse reaction (SCAR) study and the multinational severe cutaneous adverse reaction (EuroSCAR) study conducted in France, Germany, Italy, Portugal, the Netherlands, Austria, and Israel. We selected case subjects aged <15 years, hospitalized for Stevens-Johnson syndrome, Stevens-Johnson syndrome/toxic epidermal necrolysis-overlap, or toxic epidermal necrolysis, and age-, gender-, and country-matched hospital controls. Pooled crude odds ratios were estimated and adjusted for confounding by multivariate methods when numbers permitted. RESULTS. Our study included 80 cases and 216 matched controls. Antiinfective sulfonamides, phenobarbital, carbamazepine, and lamotrigine were strongly associated with the risk of Stevens-Johnson syndrome or toxic epidermal necrolysis. Significant associations were highlighted in univariate analysis for valproic acid and nonsteroidal antiinflammatory drugs as a group and for acetaminophen (paracetamol) in multivariate analysis. CONCLUSIONS. We confirmed 4 previously highly suspected drug risk factors for Stevens-Johnson syndrome/toxic epidermal necrolysis in children: antiinfective sulfonamides, phenobarbital, carbamazepine, and lamotrigine. Among more unexpected risk factors, we suspect that acetaminophen (paracetamol) use increases the risk of Stevens-Johnson syndrome or toxic epidermal necrolysis.

Oxalobacter formigenes May Reduce the Risk of Calcium Oxalate Kidney Stones

Most kidney stones are composed primarily of calcium oxalate. Oxalobacter formigenes is a Gram-negative, anaerobic bacterium that metabolizes oxalate in the intestinal tract and is present in a large proportion of the normal adult population. It was hypothesized that the absence of O. formigenes could lead to increased colonic absorption of oxalate, and the subsequent increase in urinary oxalate could favor the development of stones. To test this hypothesis, a case-control study involving 247 adult patients with recurrent calcium oxalate stones and 259 age-, gender-, and region-matched control subjects was performed. The prevalence of O. formigenes, determined by stool culture, was 17% among case patients and 38% among control subjects; on the basis of multivariate analysis controlling demographic factors, dietary oxalate, and antibiotic use, the odds ratio for colonization was 0.3 (95% confidence interval 0.2 to 0.5). The inverse association was consistently present within strata of age, gender, race/ethnicity, region, and antibiotic use. Among the subset of participants who completed a 24-h urine collection, the risk for kidney stones was directly proportional to urinary oxalate, but when urinary factors were included in the multivariable model, the odds ratio for O. formigenes remained 0.3 (95% confidence interval 0.1 to 0.7). Surprisingly, median urinary oxalate excretion did not differ with the presence or absence of O. formigenes colonization. In conclusion, these results suggest that colonization with O. formigenes is associated with a 70% reduction in the risk for being a recurrent calcium oxalate stone former.

Drugs in the aetiology of agranulocytosis and aplastic anaemia

Abstract:  Agranulocytosis and aplastic anaemia are rare but serious conditions known to be caused by numerous drugs. Most of what is known or suspected about the aetiology is based on case reports, with only a few formal epidemiological studies that provide quantitative estimates of risk. Updated results have been obtained from a combined analysis of data from 3 case‐control studies that used similar methods: the International Agranulocytosis and Aplastic Anemia Study (IAAAS), conducted in Israel and Europe; a study conducted in the northeast US; and a study conducted in Thailand. Totals of 362 cases of agranulocytosis, 454 cases of aplastic anaemia and 6458 controls were included in the analyses. The IAAAS and Thai study were population‐based, providing estimates of the incidence of the 2 dyscrasias. The overall annual incidence of agranulocytosis in the ambulatory population was 3.4/106 in the IAAAS and 0.8/106 in Thailand; by contrast the incidence of aplastic anaemia was 2.0/106 in the IAAAS and 4.1/106 in Thailand. A total of 21 compounds were significantly associated with an increased risk of agranulocytosis in the IAAAS and US studies. Excess risks ranged from 0.06 to 13 cases/106 users/wk; the most strongly associated drugs were procainamide, anti‐thyroid drugs and sulphasalazine. An association with drugs that had previously been suspected was also seen in Thailand. The overall aetiologic fractions of agranulocytosis due to drug use were 62% in the IAAAS, 72% in the US and 70% in Thailand. Eleven drugs were significantly associated with an increased risk of aplastic anaemia, with excess risks ranging from 1.4 to 60 cases/106 users in a 5‐month period. The most strongly associated drugs were penicillamine, gold and carbamazepine. Aetiologic fractions were 27% in the IAAAS, 17% in the US and 2% in Thailand, which paralleled the prevalence of use of associated drugs in the 3 populations. The present results confirm that agranulocytosis is largely a drug‐induced disease, with similar proportions accounted for in 3 disparate geographic regions. By contrast, although many of the expected associations were observed for aplastic anaemia, most of the aetiology is not explained by drugs. For all associated drugs, the excess risks are sufficiently low that blood dyscrasias should not figure prominently in the balancing of risks and benefits.

Evaluation of case reports of aplastic anemia among patients treated with felbamate.

Summary: Purpose: Felbamate (FBM) is a new antiepileptic drug (AED) that is often effective in seizure disorders refractory to other treatments; its use has been greatly restricted after cases of aplastic anemia were reported. To elucidate the putative association between FBM and aplastic anemia, we made a detailed evaluation of the first 31 reports.

Nonsteroidal anti‐inflammatory drug use in relation to major upper gastrointestinal bleeding

In a study in the United States, Sweden, and Hungary, 335 cases of gastric bleeding without predisposing factors were compared with 670 control subjects, and 239 cases of duodenal bleeding were compared with 489 control subjects. For aspirin taken at least every other day during the week before the onset of bleeding (regular use), the relative risk of gastric bleeding was 4.4 (95% confidence interval [CI], 2.9 to 6.7); for occasional use, it was 3.3 (95% CI, 2.1 to 5.0). For ibuprofen, the corresponding estimates were 1.0 (95% CI, 0.4 to 2.6) and 1.1 (95% CI, 0.5 to 2.4). For naproxen, the estimate for regular use was 4.0 (95% CI, 1.5 to 11). The estimates for any use of piroxicam (crude estimate), indo‐methacin, and diclofenac during the week before onset were 18 (95% CI, 4.1 to 83), 1.6 (95% CI, 0.4 to 5.9), and 0.9 (95% CI, 0.2 to 4.2), respectively. The corresponding relative risks of duodenal bleeding were 7.1 (95% CI, 4.2 to 12) and 2.2 (95% CI, 1.3 to 3.7) for the regular and occasional use of aspirin, 2.4 (95% CI, 0.5 to 11) and 0.8 (95% CI, 0.3 to 2.0) for ibuprofen, 12 (95% CI, 2.8 to 54) and 9.9 (95% CI, 2.3 to 44) for naproxen, 17 (95% CI, 3.6 to 79) for any use of piroxicam (crude estimate), and 1.7 (95% CI, 0.2 to 14) for any use of indomethacin. There was a significant trend in the risk of gastric bleeding with increasing dose of regular aspirin use (p = 0.002). The relative risk estimates for the regular use of 325 mg or less were significantly elevated for both gastric and duodenal bleeding at 3.1 and 6.4, respectively.

The risk of acute major upper gastrointestinal bleeding among users of aspirin and ibuprofen at various levels of alcohol consumption

Objective:Major upper gastrointestinal bleeding (UGIB) is the most important adverse effect of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). Alcoholic beverages also precipitate UGIB. This analysis was conducted to evaluate whether the deleterious effects of NSAIDs are further increased among drinkers.Methods:An interview-based, case-control study was conducted in the U.S. and Sweden; 1224 patients hospitalized with acute major UGIB due to newly occurring peptic ulcer or gastritis were compared to 2945 neighbor controls.Results:Compared with those who drank less than one drink/wk, the relative risk of acute UGIB increased with increasing alcohol consumption, rising to 2.8 among those who drank ≥21 drinks/wk. Among current drinkers, the relative risk of acute UGIB due to the use of aspirin was raised at all levels of alcohol consumption; the estimate for aspirin taken at least every other day (regular use) at doses of >325 mg among all current drinkers combined was 7.0; for regular use at lower doses, the corresponding estimate was 2.8, and for any occasional use, it was 2.4. All estimates were statistically significant. Data for ibuprofen were more limited, but the relative risk estimates did not appear to vary consistently with level of alcohol consumption. For regular use (all doses combined), the estimate among all drinkers combined was significantly elevated, at 2.7; occasional ibuprofen use was not associated with UGIB (1.2). There were insufficient data to evaluate other NSAIDs according to alcohol consumption.Conclusions:The findings suggest that acute UGIB is similarly associated with the use of the two most common nonprescription NSAIDs, aspirin and ibuprofen, at all levels of alcohol consumption. As heavy alcohol intake independently increases the risk, the incidence of UGIB is highest among persons who are both heavy drinkers and users of aspirin or ibuprofen.