Faculty Bibliography

The world of drug safety is undergoing major changes in the US, Europe and elsewhere following several major drug withdrawals, billion dollar lawsuits, NGO studies of drug safety and widespread media attention in the US. Some of the events of the past few years are reviewed along with some of the reactions and changes in the FDA and the field of drug safety followed by the author's conclusions and views on the future of drug safety

The extremely low reporting rate of cardiovascular adverse events for loratadine, the possible preferential use of loratadine in patients with pre-existing cardiovascular disorders, and the impressive lack of cardiovascular effects at extremely high concentrations in clinical and preclinical studies demonstrate the very safe cardiovascular profile of loratadine

Use of the Internet is becoming widespread throughout the world. Its use in the domain of drug safety and pharmacovigilance is spreading rapidly. Governments and industry have taken the lead in developing extensive web sites. The US Food and Drug Administration (FDA), the European Agency for the Evaluation of Medicinal Products (EMEA) and other agencies have developed sites containing enormous amounts of information both on pharmacovigilance in general and on specific drugs in particular. Under the US 'Freedom of Information Act' the FDA has put major parts of its adverse event database on line. Regulatory documents are also available from the FDA site or from hyperlinks described in the site. The US Center for Drug Evaluation and Research updates its site most days and maintains a free automated e-mail announcement service of these updates. Similarly, the EMEA updates its site frequently and publishes extensive material including regulatory documents, guidelines, European Public Assessment Reports on newly approved medications and other useful information. A free update service by e-mail is also available. Although English is the primary language used on the EMEA site, some of the information is available in other languages. Pharmaceutical companies are not using the Internet for pharmacovigilance yet. Rather, the Internet is being used for promotion of their products and for informing consumers on general information on diseases, for financial and investor data and for employment opportunities, etc. Other organisations such as lobbies, consumer groups and medical journals are also beginning to use the Internet. The electronic transmission of safety information, using the standards developed by the International Conference on Harmonization, is currently being tested for the transmission of individual patient adverse event information between companies and governments. In addition, the FDA has begun to accept adverse events from healthcare providers and consumers directly on line using an electronic version of its MedWatch form. It is expected that these developments will change the nature of the way pharmacovigilance is carried out. Significant issues will arise from this including privacy concerns. The European Union's 1995 directive on 'the protection of individuals with regard to the processing of personal data and on the free movement of such data (95/46/EC)' went into effect in October 1998. The enabling legislation now being passed by the member states will produce significant changes in the way companies and governments handle individual patient data in order to assure the privacy and protection of individuals

Roxatidine (150 mg, 312 patients) was compared with ranitidine (300 mg, 308 patients) in a randomized, double-blind, parallel-group, 6-week therapeutic study for the treatment of patients with uncomplicated, benign gastric ulcer disease. The study end points (verified by using endoscopy results) were fully healed ulcers at 4 or 6 weeks. The results of roxatidine therapy were comparable to those of ranitidine therapy: healing rates of 52% and 54% at week 4 and 77% and 76% at week 6 were recorded for roxatidine and ranitidine, respectively. The drugs produced comparable reductions in ulcer diameters and decreases in abdominal pain. Adverse events associated with both roxatidine (27%) and ranitidine (28%) were headache, diarrhea, and dizziness; rash was associated in 6 of 8 cases and in only 1 case with roxatidine. In this trial, roxatidine 150 mg once daily was as efficacious and safe as ranitidine 300 mg once daily for treatment of patients with uncomplicated, benign gastric ulcer disease

This multicenter randomized, double-blind, 4-wk study compared the new H2-receptor antagonistic roxatidine (R) to placebo (P) for treatment of endoscopically diagnosed active duodenal ulcer disease. Subjects were evaluated after 2 and 4 wk of treatment. Those whose ulcer was unhealed at 2 wk received 2 more weeks of treatment before final evaluation. Ulcer healing (endoscopically determined) with roxatidine was more effective than placebo at both wk 0-2 (R = 33.9%, P = 21.9%, p = 0.018) and wk 2-4 (R = 68.2%, P = 29.7%, p less than 0.001), with an overall 4-wk effectiveness of 78.9% compared to 44.8% (p less than 0.001). At the end of treatment, average maximum ulcer diameter diminished 83% in R and 50% in P (p less than 0.001). Roxatidine was also more effective than placebo in decreasing abdominal pain (p less than 0.001), decreasing the number of antacid tablets taken for pain relief (p less than 0.001), improving dyspeptic symptoms (p less than 0.001), and permitting return to a normal routine for subjects with previous illness-imposed restrictions on work and/or other daily activities. The profile of laboratory values and adverse experiences demonstrated roxatidine to be safe and well-tolerated. The efficacy of roxatidine as evaluated by the healing rate of duodenal ulcer and reduction in abdominal pain emphasize its value as an addition to the family of H2-receptor antagonists

Ten patients with chronic occlusive arteriosclerosis received single oral doses of 100, 200, 400, 800, and 1200 mg pentoxifylline in a single-blind, placebo-controlled study. Blood samples were drawn at baseline and at 2 hour intervals for 6 hours. Drug and metabolite levels, as well as red cell filterability (deformability), were determined on all blood samples. Statistically significant dose-response increases of red cell filterability were found 4 and 6 hours after oral medication with the dosages of 200 to 1200 mg pentoxifylline. These changes were proportional to the plasma levels of pentoxifylline and metabolites 1 and 5 of this agent. Attempts were made to develop a suitable animal-screening method for agents with similar activity and to determine whether red blood cells in the absence of disease-related abnormalities may respond to this type of therapy. Five healthy Macaca arctoides monkeys were given 24 mg/kg pentoxifylline intravenously, and measurable but lesser increases in red cell deformability were recorded than in the patients

Trimipramine, a sedating tricyclic antidepressant, and imipramine were compared on polysomnographic parameters during a 4-week double-blind trial in depressed patients with insomnia and anxiety. Trimipramine eliminated objective evidence of sleep disturbance. This was not the case with imipramine, although depression improved similarly in both groups. Subjects' sleep appeared unchanged or more disturbed at the end of the treatment with imipramine. For trimipramine, the major changes in sleep parameters occurred during the first week of drug administration and did not parallel the gradual changes seen in the measures of depression. Additionally, trimipramine did not suppress REM sleep even in a subgroup of six trimipramine patients who had short rapid-eye-movement (REM) sleep latencies during the placebo baseline period, even though their depression was alleviated. The data demonstrate that (a) antidepressants may vary in their effects on sleep, even though they have similar effects on depression; (b) REM sleep suppression does not necessarily accompany improvement in depression; and (c) reports of improved sleep by patients undergoing antidepressant therapy may not reflect improvement on objective measures of sleep. The different sleep effects suggest the possibility of different antidepressant pathways

The effects of pentoxifylline on intermittent claudication were evaluated at a dose of 1200 mg/day in an open-label twelve-week study on geriatric patients with chronic occlusive arterial disease (COAD). Standardized treadmill testing and clinical signs and symptoms of COAD were followed up before and during drug administration. Twenty-four subjects with a mean age of 73.5 years, capable of walking between 20 and 200 meters on the treadmill, were entered into the trial; 22 participated for eight weeks and 19 completed the study in terms of treadmill walking distance measurements at 12 weeks. The mean walking distance for all patients was increased 111% over baseline at week 12. Thirteen subjects were considered drug responders (greater than or equal to 50% increase in treadmill walking distance) and 9 were considered nonresponders (less than 50% increase). Improvements in clinical signs and symptoms of COAD were noted. Decreases in elevated systemic systolic pressures (but not diastolic) were unexpectedly observed in many drug responders. Seven of 19 males reported sexual function improvements while receiving pentoxifylline. Fourteen (58%) of the 24 subjects reported mild side effects of dyspepsia, nausea, vomiting, dizziness, headache, or insomnia; no subjects were withdrawn from the study because of side effects. In summary, pentoxifylline improved function and symptoms in 13 of 22 geriatric patients with intermittent claudication; the drug was safe and well tolerated at the usual dosage in this geriatric patient population