[Risk related to withdrawal from non-psychotropic drugs]

A review of the available literature concerning sudden withdrawal of drugs shows that withdrawal syndrome have occurred with centrally antihypertensive drugs, beta-blockers on anginal patients, antiparkinsonian drugs and glucocorticoids. Because of a lack of controlled trials led among a large number of individuals, the correct frequency of this withdrawal syndrome is unknown. In most patients, it's hard to distinguish a return to a previous state from an overshoot phenomenon. In that way, gradual and supervised withdrawal of these agents should prevent the complication of sudden cessation of these therapy.

[Drug-induced benign intracranial hypertension. Apropos of a case with amphotericin B. Review of the literature]

Benign intracranial hypertension (BICH) is a rare adverse event. We report the case of a 31-year-old female drug addict who had been seropositive for HIV since 1987. She had stage IV C1 AIDS, and was receiving intravenous amphotericin B for generalized cryptococcosis with no neuromeningeal involvement. She developed BICH that regressed when the antifungal drug was withdrawn and treatment for cerebral edema was started. BICH is a clinical entity involving intracranial hypertension with no focal neurological signs or detectable intracranial lesion. The manifestations include headache, transitory or permanent visual disturbances (diplopia, loss of visual acuity) and the perception of intracranial noise. The cerebrospinal fluid is under increased pressure but the composition is normal. The eye fundus examination shows papillary edema, and the neuroradiological workup is normal. BICH can only be diagnosed once an expansive intracranial process, neuromeningeal infection, and non-communicative hydrocephalus have been ruled out. In the majority of cases, no etiology is found. Such cases of idiopathic BICH usually occur in overweight young women, although drugs can be implicated. Amphotericin B has not previously been held responsible for BICH. On the basis of this observation, we present a review of the literature.

[Comparative study of data banks on drug interactions]

Authors have listed 9 criteria for testing scientific quality of computerized drug-interactions data banks. Pair of drugs with or without interactions, have been selected for each of these criteria and have been used for interrogation of eight data banks. None of these are completely satisfactory but errors or omissions are more or less important.

[Economic impact of adverse drug effects. Some reflections]

The cost of adverse drug effects first began to be analyzed in the 1960s, with an evaluation of related admissions to hospital in the USA. The average cost per patient of adverse events requiring hospitalization in France was estimated at 6,250 F in neurology units in 1979/1980, and 14,920 F in geriatric units in 1984. Fifty per cent of these events were avoidable. A second approach is to measure the cost of certain iatrogenic manifestations, e.g. fever due to fipexide, stenosis and perforation of the small intestine due to potassium chloride, gastrointestinal bleeding due to NSAIDs, kidney damage due to aminosides, etc. Calculations of the economic impact of adverse drug effects must also take into account indirect costs such as loss of productivity. The lack of such studies should not make health care specialists forget the magnitude of the problem.

[Thrombopenia due to pefloxacin (Peflacine): dose-dependent toxicity?]

Pefloxacin (Peflacine) can give rise to thrombocytopenia, although the responsibility of the drug can be difficult to demonstrate in infectious patients and those receiving other drugs simultaneously. We have collated 18 cases in which the responsibility of pefloxacin was suspected. In 13 cases, the patients were also taking other drugs which may have been contributory (heparin, Bactrim, Augmentin, ranitidine,...). The remaining five cases were of particular interest as pefloxacin was the only drug administered. The mean age of the patients was 75 years, and the mean bodyweight 56 kg (range, 47-65 kg). The pefloxacin dosage was 800 to 1,600 mg/day i.v. or p.o., i.e. 13-18 mg/kg/day. Thrombocytopenia occurred from five to 19 days after beginning treatment and resolved between 7 and 12 days after drug withdrawal. A number of factors argue in favor of dose dependency: 1 patient had high plasma concentrations (peak and residual); thrombocytopenia occurred in one patient when the previous, well-tolerated dosage of 800 mg/day (for 15 days) was increased to 1,600 mg/day; thrombocytopenia resolved in one patient when the dosage was reduced to 400 mg/day (1 tablet) and continued for a further 10 days. This toxic reaction may be avoided by reducing the drug dosage to 400 mg/day in elderly patients with a low bodyweight. Differential blood counts appear to be warranted for patients at risk.

[Tolerance of famotidine. Study of network of sentinel physicians in pharmaco-vigilance]

This paper presents the results of an intensive surveillance based on a network of general practitioners and following 200 patients treated by famotidine 40 mg per day during 6 to 8 weeks. Four patients with a previous experience of adverse reaction to another H2 antagonist did not relapse with famotidine. None interaction was reported with drugs such as beta-blockers, oral anticoagulants, theophylline, benzodiazepines, calcium antagonists. Twenty four clinical side effects were reported; For 5 patients (2.5%) the treatment had to be stopped. The most common side effects were neurological. The results are compared with those of previously published studies.

[Cardiac toxicity of fluoro-uracil. Typical and atypical aspects. Apropos of 8 cases]

The cardiac toxicity of 5 fluoro-uracil, an antimitotic agent widely used in various protocols, has been known for 16 years. Several cases have been reported in the literature, leading to the suggestion, without formal evidence, that the chief mechanism responsible for this cardiac toxicity is "classical" coronary spasm. However, certain clinical aspects already described may shed doubt on this theory. On the basis of 8 cases, the authors report different clinical pictures all caused by cardiac toxicity of 5FU. It is of interest to note that chest pain with the classically described electrocardiographic changes did not apply in the majority of cases. The commonest pattern was asymptomatic electrocardiographic abnormalities and/or arrhythmias without angina. Among the reported cases, one patient had pain with electrocardiographic abnormalities, recurrent after the withdrawal of 5FU and resistant to maximal medical treatment, despite the absence of any coronary disease or signs of spasm. One patient had a first myocardial infarction, later rechallenge with the drug resulting in failure. In another patient, with known coronary disease, 5FU probably cause cardiogenic shock. In total, some of our cases, as well as other features described in the literature, raise questions as to the pathophysiology of the cardiac toxicity of 5FU.