Adverse reactions case-control studies

Field experience, backed by a case-control study of 1991, strongly suggests that patients taking beta-blockers have a risk ratio of adverse reactions to contrast media of 2.7. Hypotension is the main effect, sometimes dangerously so, even with non-ionic media (SEDA-11, 411) (SEDA-17, 536) (311). 

Russmann S, Kaye JA, Jick SS, Jick H (2005) Risk of cholestatic liver disease associated with flucloxacillin and fiucloxacillin prescribing habits in the UK cohort study using data from the UK General Practice Research Database. Br J Clin Pharmacol 60 76-82 Rzany B, Correia O, Kelly JP, Naldi L, Auquier A, Stem R (1999) Risk of Stevens-Johnson syndrome and toxic epidermal necrolysis during first weeks of antiepileptic therapy a case-control study. Study group of the international case control study on severe cutaneous adverse reactions. Lancet 353 2190-2194... 

Nervous system The effects of lamotrigine (n=29), levetiracetam (n = 38), and pheno-barbital (n=28) have been evaluated in patients with seizures and Alzheimer s disease in a prospective, randomized, three-arm parallel-group, case-control study with a 4-week dosage adjustment and a 12-month evaluation period [180. The adverse reactions were somnolence (30%) and weakness (13%). Patients treated with lamotrigine showed a slight decline in Mini Mental Test scores and other cognitive scores and scored better on measures of mood. 

Gau SS, Chao PF, Lin YJ, Chang CJ, Gau CS. The association between carbamazepine and valproate and adverse cutaneous drug reactions in patients with bipolar disorder a nested matched case-control study. J Clin Psychopharmacol 2008 28(5) 509-17. 

Drug contamination Adverse reactions to heparin contaminated with oversulfated chondroitin sulfate have been evaluated in a US case-control study of patients in dialysis facilities who had signs and symptoms of allergic reactions after 1 November 2007 [122 ]. There were 152 adverse reactions associated with heparin in 113 patients from 13 states from 19 November 2007 to 31 January 2008. The use of heparin manufactured by Baxter Healthcare was the factor most strongly associated with reactions, which occurred in 100% of 21 facilities in which cases were reported versus 4.3% of 23 control facilities. Vials of heparin manufactured by Baxter from facilities that reported reactions contained a contaminant identified as oversulfated chondroitin sulfate. Adverse reactions to the contaminated heparin were often characterized by hypotension, nausea, and shortness of breath within 30 minutes of administration. Of 130 reactions for which information on the heparin lot was available, 128 occurred in a facility that had contaminated heparin on the premises. Of 54 reactions for which the lot number of the heparin was known, 52 occurred after the administration of contaminated heparin. 

Thyrotoxicosis is a type of very late adverse reaction seen after iodine-based contrast media. Untreated Graves disease and multinodular goiter and thyroid autonomy are risks for this adverse reaction. Patients with hyperthyroidism are usually advised not to have iodinated contrast media injection. Patients with normal thyroid function are thought to be at low risk for this condition [3 ]. There are few studies that assess the relationship between iodinated contrast media exposure and thyroid function disorders. In a nested case-control study of 4096 patient intervals, iodinated contrast exposure was associated with incident hyperthyroidism (odds ratio or OR = 1.98 95% confidence interval or Cl = 1.08-3.60) but not statistically significantly associated with incident hypothyroidism (OR = 1.58 95% Cl, 0.95-2.62). Also, incident overt hyperthyroidism (follow-up thyrotropin levelsO.l mlU/L OR, 2.50 95% Cl, 1.06-5.93) and incident overt hypothyroidism (follow-up thyrotropin level >10 mlU/L OR, 3.05 95% C3,1.07-8.72) were found to be associated with iodinated contrast media exposxue [4 ]. 

In addition to the three more recent withdrawals of Merital, Serzone, and Cylert, I have also reviewed the entire list of serious adverse reactions to psychiatric drugs detected during the postmarketing period in the GAO (1990) study. It seems probable that every one of them was discovered and confirmed through a combination of the SRS, individual case reports, and general clinical experience. As far as I can ascertain, not one of these adverse reactions was primarily, if at all, identified by means of a controlled clinical trial. As a result of postmarket discoveries, alprazolam (Xanax) had rage added to the label as a paradoxical reaction, and amoxapine (Asendin) had NMS added. 

The methods for detecting adverse reactions include a continued clinical trial with a reduced number of clinical and laboratory controls, a kind of post-marketing surveillance (Slone et al. 1979) case-referent studies in which patients with an illness of interest are compared with a group of people without that illness and a... 

In a retrospective, case-matched control study of 43 patients who received aerosolized and intravenous colistin, who were matched with 43 patients who received intravenous colistin alone, eight in each group developed nephrotoxicity [107. None required renal replacement therapy or withdrawal of colistin. There were no respiratory adverse reactions in those who received aerosolized colistin. 

Skin testing with vancomycin and teicoplanin has not been well studied and the procedure remains to be validated with both positive and negative predictive values unknown. Skin test results, and particularly details of drug concentrations used and methodologies employed, are hard to find in the vancomycin-teicoplanin literature on adverse reactions. In a case study of vancomycin anaphylaxis followed by successful desensitization, intradermal skin tests with the drug were positive at a concentration of 0.1 pg/ml. Control subjects showed positive responses at concentrations of 10 pg/ml or greater. A loss of skin test reactivity to vancomycin has been demonstrated in one case study after successful desensitization to the drug. 

Placebo-controHed studies In a doubleblind, randomized, placebo-controlled study in 105 unconscious adults with suspected drug overdose, 73 of whom had taken benzodiazepines, flumazenil caused adverse effects in nine cases agitation (n = 3), a depressive mood (n = 3), nausea and vomiting (n = 1), shivering (n = 1), and one severe adverse reaction—a sudden fall in blood pressure in a 28-year-old woman in deep coma after combined poisoning with benzodiazepines and maprotiline [95 "]. 

---