Analgesics for pain after traumatic or orthopaedic surgery: what is the evidence-a systematic review

OBJECTIVE

To assess analgesic drugs in the treatment of postoperative pain after traumatic and orthopaedic surgery (TOS).

DESIGN

A systematic review of randomised clinical trials (RCTs).

DATA SOURCES

Electronic PubMed, EMBASE, The Cochrane Library, and hand searches.

STUDY SELECTION

RCTs of analgesics administered by oral, intramuscular, intravenous, subcutaneous or rectal route, were compared to other analgesics or placebo, in patients under TOS. Study design, characteristics of the study population, analgesic drugs tested, pain intensity and pain relief scores, and adverse effects were assessed.

RESULTS

Ninety-two RCTs (9,596 patients) met our inclusion criteria. Forty-two (46%) were placebo-controlled, and 50 (54%) were direct comparisons between non-opioid, opioid, and/or combinations of both. Patients' mean age (SD) was 49 years (18). In most trials, gastrointestinal ulcer, liver and renal diseases were exclusion criteria. Only 30 trials (33%) were double-blind and reported standardised outcomes of pain intensity and pain relief; 19 of these were single-dose, and follow up of analgesic effects lasted no more than 12 h in 23 (77%). Globally, only nine trials (10%) were double blind, described dropouts or withdrawals, performed analysis by intention to treat, and reported the effects magnitude.

CONCLUSION

Evidence from RCTs on the treatment of postoperative pain after TOS is inadequate for clinical decision making. Assessment of analgesics in pain after TOS should be based on agreed clinically relevant outcomes, in representative patients, and for longer observation periods. In addition, it should include direct comparisons between candidate drugs or their combinations and between various drug administration schedules.

Oral antispastic drugs in nonprogressive neurologic diseases: a systematic review

OBJECTIVE

To assess the efficacy of oral drugs in the treatment of spasticity in patients with nonprogressive neurologic disease (NPND).

METHODS

Systematic review of double-blind randomized controlled trials of antispastic oral drugs in the treatment of spasticity in NPND.

DATA SOURCES

Electronic MEDLINE, PubMed, Cochrane Library, and hand searches.

RESULTS

Twelve studies (469 patients) were included (6 on stroke, 3 on spinal cord diseases, and 3 on cerebral palsy). Tizanidine was assessed in four trials (276 patients, 142 exposed), dantrolene in four (103, 93), baclofen in three (70, 55), diazepam in two (127, 76), and gabapentin in one (28, all exposed). Most trials were of small size, of short duration, and their methodologic quality was inadequate. Ten trials were controlled with placebo and only two were direct comparisons between drugs. Efficacy outcome variables were heterogeneous. Only four reports described the magnitude of the antispastic effect. The incidence of adverse drug effects (drowsiness, sedation, and muscle weakness) was high.

CONCLUSION

Evidence on the efficacy of oral antispastic drugs in NPND is weak and does not include evaluation of patients' quality of life. If any, efficacy is marginal. Adverse drug reactions were common. Better methodologic instruments are needed for the evaluation of antispastic treatment.

Upper gastrointestinal bleeding associated with antiplatelet drugs

BACKGROUND

The risk of major upper gastrointestinal bleeding associated with various antiplatelet drugs and the protection conferred by gastroprotective agents are not well defined.

AIM

To estimate the risk of upper gastrointestinal bleeding associated with the use of antiplatelet drugs and its prevention by gastroprotective agents.

METHODS

In a case-control study, we compared all cases of upper gastrointestinal bleeding from a gastric or duodenal lesion in patients over 18 years of age (2813 cases), with 7193 matched controls. Odds ratios of upper gastrointestinal bleeding for individual antiplatelet drugs with adjustment for potential confounders were estimated.

RESULTS

The individual risks of upper gastrointestinal bleeding were cardiovascular acetylsalicylic acid 4.0 (3.2-4.9), clopidogrel 2.3 (0.9-6.0), dipyridamole 0.9 (0.4-2.0), indobufen 3.8 (1.2-12.2), ticlopidine 3.1 (1.8-5.1) and triflusal 1.6 (0.9-2.7). Concomitant proton pump inhibitors decreased all risk estimates. For acetylsalicylic acid plus a proton pump inhibitor, the odds ratio was 1.1 (0.5-2.6). As a group, antiplatelet drugs accounted for 14.5% of all cases of upper gastrointestinal bleeding, i.e. 58 per million per year (334 per million per year among those older than 70 years).

CONCLUSIONS

The risk of upper gastrointestinal bleeding is substantially decreased by the concomitant use of proton pump inhibitors. The risk of acetylsalicylic acid plus a proton pump inhibitor seems lower than that of ticlopidine or clopidogrel.

Medical speciality and pattern of medicines prescription

OBJECTIVE

To describe the prescribing patterns and their quality in relation to the prescriber's medical specialty in a defined population.

METHODS

The study was done on a random sample of all primary care medical prescriptions made through the social security system during 1 year in Andorra, a small European country. Number and type of prescribed medicines, prescribers' medical speciality and patients' age and gender were recorded. Medical specialties considered were General Practice, Paediatrics, Cardiology, Pneumology, Gynaecology, Ophthalmology and Other. A set of various quality indicators [World Health Organisation (WHO)/International Network for Rational Use of Drugs (INRUD) indicators and others] was used.

RESULTS

The number of medicines prescribed per encounter varied depending on the prescriber's medical specialty and patient's age. Cardiologists and pneumologists tended to prescribe more medicines than other medical specialties. Patients older than 65 years received more prescriptions than younger adults, mostly at the expense of cardiovascular drugs. The contribution of the various groups and subgroups of medicines and the scores of various prescribing indicators showed wide variability across the medical specialties.

CONCLUSION

Prescribing patterns and indicators of prescription quality show wide variability depending on the prescriber's medical specialty. This has important implications for priority setting in information, continuous education and research.

Incidence of Agranulocytosis in Southwest France

BACKGROUND

Updated knowledge of background event rates is fundamental to risk assessment.

OBJECTIVE

To estimate the incidence of agranulocytosis in the general population in Southwest France.

METHODS

All definite cases of acute non-cancer drug-related agranulocytosis in subjects aged more than 16 years were systematically retrieved weekly from Medical departments or labs in the catchment area (approximately 3.5 millions inhabitants). Event rates were compared to population figures from 1999 census data, and Poisson 95% confidence intervals computed.

RESULTS

From January 1st 1997 to December 31st 1998, 87 cases of agranulocytosis were identified, 58 being validated by an independent ad hoc panel of experts. The overall annual incidence rate was 9.2 per million inhabitants (95%CI: 6.9;13.0); 7.7 (95%CI: 4.8;11.7) per million in men, and 10.5 (95%CI: 7.2; 14.8) per million in women. These rates of all-cause acute agranulocytosis can be used as expected background reference rate for specific risk assessment.

Impact of analgesic drug-use guidelines for the management of postoperative pain: a drug utilization study

OBJECTIVE

Postoperative pain is inadequately treated in many surgical settings. The present study evaluates the impact of analgesic drug-use guidelines in the management of postoperative pain.

PATIENTS AND METHODS

A prospective drug utilization study was carried out in 3 stages in a traumatology, orthopedic and rehabilitation tertiary hospital. The first stage, aimed at describing the patterns of use of analgesic strategies in the management of postoperative pain, identified habits, practices and misconceptions regarding this therapeutic area. After this, an ad hoc representative institutional working group agreed on analgesic drug-use guidelines for the management of postoperative pain. These were then published, presented and discussed with surgeons and nurses. After the guidelines had been implemented, their impact was evaluated in terms of the analgesics used, their dosage and their administration schedule.

RESULTS

101 patients were studied before the implementation of the guidelines and 108 patients after. Patients receiving opiate analgesics during the immediate postoperative period increased from 70-94% (p < 0.05). First-choice analgesics used according to the guidelines increased from 40-89% of choices after the implementation of the guidelines (p < 0.05). Administration of analgesics at regular predetermined intervals increased from 45-58% of medical orders, but this increase was not statistically significant (p = 0.07). Prescription of analgesics at adequate doses increased from 67-87% (p < 0.05).

CONCLUSION

Education on the treatment of postoperative pain is made up of several messages including the drug of choice and dose regimen. Prescribers seemed more receptive to a change in drug rather than issues related to the correct dose regimen. More research is needed to assess how educational activities can improve the management of postoperative pain.

Bioavailability of two metamizole (dipyrone) solutions as single doses of 2 g versus metamizole capsules

OBJECTIVE

The aim of this study was to investigate the extent and the rate of absorption of metamizole, appearing in blood as methylaminoantipyrine (MAA), from a new oral solution and a parenteral solution administered by the oral route relative to capsules.

METHODS

An open, randomized, 3 single-dose (2 g metamizole), crossover study with intervals of 7 days between periods was performed in 19 male and female healthy volunteers (age 22 - 45 years, body weight 49 - 88 kg, body height 156 - 189 cm). Metamizole metabolites were measured with an HPLC technique. The test formulations were considered bioequivalent with the reference formulation if the 90% confidence limits of the AUC0-->infinity and Cmax ratios and the tmax differences were within the range of 80 - 125%.

RESULTS

The 90% confidence limits of the comparisons between capsules (reference) and oral solution, capsules (reference) and ampoules, and ampoules (reference) and oral solution were 98.5 - 117.8, 99.5 - 132.6 and 81.3 - 105.8 for AUC0-->infinity 98.7 - 119, 101.7 to 129.2, and 82.1 - 104.8 for Cmax, and 84.4 to 115.6, 100 - 105.6 and 70.3 - 100 for tmax, respectively.

CONCLUSION

The oral solution was bioequivalent to capsules with regard both to the extent and the rate of MAA absorption. Metamizole as oral solution was bioequivalent to reference ampoules in the extent of MAA absorption, but absorption rate was faster. Ampoules showed a higher MAA bioavailability than capsules.

Agranulocytosis associated with calcium dobesilate clinical course and risk estimation with the case-control and the case-population approaches

OBJECTIVE

Calcium dobesilate is used in the treatment of diabetic retinopathy, chronic venous insufficiency, haemorrhoids and other ill-defined vascular conditions. It has been associated with agranulocytosis in anecdotal reports. We describe the clinical course of a series of patients who developed agranulocytosis while taking this drug, and we estimate the risk by means of both a case-control and a case-population strategy.

METHODS

All cases of agranulocytosis meeting strict predefined diagnostic criteria in an area of 3.3 to 3.9 x 106 inhabitants in the period 1980-1998 were identified. Cases and age-, gender- and hospital-matched controls were interviewed with a structured questionnaire including a detailed drug history. Each case was reviewed and confirmed by a haematologist, who was blind with respect to drug exposures. Consumption data were used to estimate the risk of agranulocytosis associated with calcium dobesilate using a case-population approach in which the incidence of agranulocytosis among users of calcium dobesilate was compared with that among the non-exposed population.

RESULTS

After a follow up of 68.55 x 10(6) person-years, 345 cases of agranulocytosis (242 community cases) were assembled. Reliable information was obtained from 216 cases. Two patients exhibited positive rechallenge. Twelve cases (5.6%) and 5 of 1380 controls (0.4%) had taken calcium dobesilate in the week before. With the case-control approach, the odds ratio was 23.66 [95% confidence interval (CI), 7.54-74.24], the attributable risk was 5.3% (95% CI, 3.0-9.4), and the number of cases attributable to dobesilate in the study area during the study period was 12.8. The case-population estimates were an incidence of 121.03 cases per 10(6) patient-years, a relative risk of 39.55 (95% CI, 17.96-77.49), an attributable risk of 6.73% (CI 3.4-12.9), and 16.30 cases attributable to dobesilate in the study area during the study period.

DISCUSSION

This study adds to evidence indicating that the case-population method is adequate for the study of rare type B adverse drug reactions. An additional advantage of this approach is that the incidence of the disease of interest among those exposed to the drug can be estimated. The risk of agranulocytosis associated with calcium dobesilate should be considered in relation to poor evidence of its clinical efficacy.

Beta-adrenergic blocking agents in heart failure: benefits of vasodilating and non-vasodilating agents according to patients' characteristics: a meta-analysis of clinical trials

BACKGROUND

In patients with heart failure, beta-adrenergic blocking agents reduce overall and cardiovascular mortality. This meta-analysis aimed at clarifying their effect on sudden death, the magnitude of their benefit according to the cause of heart failure, and whether there is any difference between vasodilating and nonvasodilating agents.

METHODS

Randomized, clinical trials were included if they evaluated a beta-adrenergic blocking agent without intrinsic sympathomimetic activity, included a control group receiving placebo or standard treatment, evaluated mortality on an intention-to-treat basis, and lasted at least 8 weeks.

RESULTS

Twenty-one trials with 5,849 patients (3,130 receiving beta-blockers) were included. Median length of treatment was 6 months. Most patients had mild or moderate heart failure and were treated with angiotensin-converting enzyme inhibitors, diuretics, and digitalis. The beta-blockers significantly reduced overall mortality, cardiovascular mortality, and mortality due to pump failure and sudden death by 34% to 39%. The decrease in overall mortality in patients with ischemic heart disease (IHD) (30%) was no different from that among patients with non-IHD (26%) (P = .08). The reduction in overall mortality was greater with vasodilating than with nonvasodilating agents (45% vs 27%; P = .007), particularly in patients without IHD (62%), compared with those with IHD (22%; P =.03).

CONCLUSIONS

In patients with heart failure, beta-blockers reduce total and cardiovascular mortality at the expense of a decrease in mortality due to pump failure and sudden death. The magnitude of the benefit is similar in patients with IHD and in those with non-IHD. Vasodilating beta-blockers have a greater effect on overall mortality than nonvasodilating agents, particularly in patients with non-IHD.

Agranulocytosis induced by pyrithyldione, a sedative hypnotic drug

OBJECTIVE

Pyrithyldione, a sedative-hypnotic drug with a poor clinical pharmacological development, was associated with anecdotal cases of agranulocytosis in the 1940s in the USA, in the 1960s and 1970s in the ex-Democratic Republic of Germany and in the 1980s in Japan. We describe the estimation of the risk of agranulocytosis associated with its use in Spain, which led to its withdrawal from the market.

METHODS

In collaboration with the haematology units of all the hospitals in a defined area (3.3-3.9 x 10(6) inhabitants), all cases of agranulocytosis meeting strict diagnostic criteria were identified. Each case - defined as an episode of agranulocytosis - was reviewed by a haematologist without knowledge of previous drug exposures. Cases and age-, gender- and hospital-matched controls were interviewed with a structured questionnaire about previous drug exposures. In addition, in order to estimate the risk of pyrithyldione-associated agranulocytosis through a case-population approach, its consumption among the cases was compared with its consumption among the general population.

RESULTS

After a follow-up of 66.5 x 10(6) person-years, 330 cases of agranulocytosis (230 community cases) were assembled. Reliable information on previous exposures was obtained for 204 cases. They were compared with 1314 controls. Eleven patients (14 cases, 6.9%) and zero controls had been exposed to pyrithyldione. The adjusted OR was 200.11 (CI 95% 22. 62-infinity). All patients were female; none had a fatal outcome; three exhibited positive rechallenge; and all had concomitantly taken other drugs. Although pyrithyldione was a prescription-only medicine, only 8% had been dispensed with medical prescriptions. Assuming the worst case, i.e. that all the exposed cases could be attributed to pyrithyldione, the incidence was 35.6 cases per 100, 000 patient-years (95% CI, 18.9-60.9), which gives a risk ratio estimate of 109.6 (57.5-191.5) if compared with the incidence of agranulocytosis among the non-exposed population [3.26 cases (CI 95% 2.83-3.71) per 10(6) inhabitants and per year].

DISCUSSION

Pyrithyldione was viewed by pharmacists as a mild hypnotic, and apparently this had conferred to this drug an unjustified image of safety. The National Commission of Pharmacovigilance recommended to the Ministry of Health its withdrawal from the market when eight cases of agranulocytosis had been identified. However, it took more than 2 years to withdraw it, and six additional cases occurred in the study area. This illustrates the need for quick regulatory action when pharmacoepidemiological data suggest an unfavourable benefit/risk ratio.

Management of postoperative pain in abdominal surgery in Spain. A multicentre drug utilization study

AIMS

Postoperative pain is common in hospital-admitted patients. Its management is determined by different therapeutic traditions and by the attitudes of health professionals in each hospital. The aim of this study was to describe the patterns of prescription and administration of analgesic drugs used for postoperative pain after abdominal surgery in Spanish hospitals, to know the prevalence and the severity of postoperative pain, and to determine the extent of variability in the management of postoperative pain among the participating centres.

METHODS

The study was a multicentre descriptive cross-sectional drug utilization study in 12 Spanish hospitals. The subjects were an unselected sample of consecutive patients undergoing abdominal surgery, admitted between October 1994 and January 1995. For each patient, information about the surgical procedure and the use of analgesics was prospectively collected. The severity of postoperative pain was assessed during the first day after surgery by means of a six-category (none, mild, moderate, severe, very severe, and unbearable) rating scale and a visual analogue scale (VAS).

RESULTS

Nine hundred and ninety-three patients (547 men) were included. The most common surgical procedures were inguinal hernia repair (315, 32%), cholecystectomy (268, 27%), appendectomy (140, 14%), bowel resection (137, 14%), and gastric surgery (58, 6%). Fifty-nine percent of patients (587) received nonopioid analgesics only, 9% (89) received opioid analgesics only, and 27% (263) received both opioid and nonopioid analgesics. The most frequently administered drugs were metamizole (667 patients) and pethidine (213 patients). Although in the majority of medical orders the administration of analgesics was scheduled at regular time intervals, the majority of actual doses were given 'as-needed'. The average administered daily doses of all analgesics were lower than those prescribed. Thirty-eight percent (371/967) of patients rated their maximum pain on the first day as severe to unbearable. Wide interhospital variability was recorded in the surgical procedures which had been performed, in the analgesics used, and also in the pain scores referred by patients. The percentage of patients in each centre who suffered severe to unbearable pain varied from 22 to 67%.

CONCLUSIONS

In Spain many patients still suffer severe pain after abdominal surgery, and this seems to be due to an inadequate use of analgesics. Wide interhospital variability in the management of postoperative pain and in its prevalence was also recorded.

Topical heparin for the treatment of acute superficial phlebitis secondary to indwelling intravenous catheter. A double-blind, randomized, placebo-controlled trial

OBJECTIVE

To assess the clinical efficacy of a topical gel containing 1000 IU x g(-1) of heparin, applied three times daily for a maximal period of 7 days to patients with acute superficial phlebitis secondary to indwelling intravenous catheter.

METHODS

A Double-blind, randomized, placebo-controlled study was conducted in one of the internal medicine wards of a tertiary General Hospital in Barcelona, Spain. Inpatients of both genders over 18 years of age that developed superficial phlebitis and gave informed consent were included in the study. The sample size estimation was 132 patients. Sixty-six patients were allocated to each group. There were five protocol deviations and 24 withdrawals in the intervention group, and one protocol deviation and 25 withdrawals in the control group. Consequently, 37 patients in the intervention group and 40 in the control group completed the trial. The main outcome measure was the disappearance of the symptoms and signs of superficial phlebitis. Clinical course, investigator's global impression and adverse events were also recorded.

RESULTS

According to the intention-to-treat analysis, after treatment for 7 days superficial phlebitis healed in 27 of the 61 patients (44.3%) who received topical heparin, and in 17 of the 65 patients (26.1%) receiving placebo, giving a relative risk [95% confidence interval (CI)] of 1.69 (1.03-2.78). This indicates that six patients (95% CI, 3-72) have to be treated in order to induce one additional healing. The clinical course and the overall clinical impression were similar in both groups. One patient treated with topical heparin developed mild urticaria.

CONCLUSION

Topical heparin is safe and effective for the treatment of superficial phlebitis secondary to indwelling intravenous catheter.

Possible association between ocular chloramphenicol and aplastic anaemia--the absolute risk is very low

AIMS

To determine whether topical ocular chloramphenicol increases the risk of aplastic anaemia and to estimate the magnitude of this risk, if any.

METHODS

Population-based prospective case-control surveillance of aplastic anaemia in a community of 4.2 million inhabitants from 1980 to 1995 (67.2 million person-years) plus case-population estimate of the risk, based on sales figures of ocular chloramphenicol in the study area during the study period.

RESULTS

One hundred and forty-five patients with aplastic anaemia and 1,226 controls were included in the analysis. Three cases (2.1%) and 5 controls (0.4%) had been exposed to ocular chloramphenicol during the relevant etiological period. The adjusted odds ratio was 3.77 (95% confidence interval, 0.84-16.90). Two cases had also been exposed to other known causes of aplastic anaemia. The incidence of aplastic anaemia among users of ocular chloramphenicol was 0.36 cases per million weeks of treatment. The incidence among non users was 0.04 cases per million weeks.

CONCLUSIONS

An association between ocular chloramphenicol and aplastic anaemia cannot be excluded. However, the risk is less than one per million treatment courses.

Trends of prescribing patterns for the secondary prevention of myocardial infarction over a 13-year period

OBJECTIVE

The efficacy of beta-adrenergic blocking agents and acetylsalicylic acid in the secondary prevention of myocardial infarction has been well recognized since the beginning of the 1980s. In a previous paper, however, we reported a lower than expected use of these drugs during the period 1982 1988. In 1989 the results of this survey were presented and discussed with the prescribing physicians. In the present paper we describe the prescription patterns for the same indication and in the same centre over the following 6 years (1989-1994). We also describe the use of angiotensin-converting enzyme (ACE) inhibitors, for which efficacy in certain subgroups has been recently shown.

METHODS

Random samples of patients discharged from our hospital between 1989 and 1994 with a diagnosis of acute myocardial infarction with Q-wave were studied. Information about diagnoses, other clinical variables and treatments prescribed at discharge was obtained from the hospital discharge forms. The results were compared with those obtained in the previous study.

RESULTS

We studied 514 patients (80% men) with a median age of 59 years (range 31-89). The proportions of patients prescribed beta-adrenergic blocking agents and acetylsalicylic acid increased from 34% and 28%, respectively, in 1986-1988, to 62% and 75% in 1989 1991. In 1994 they had reached a steady state (63% and 71%). In addition, a continued decrease in the use of calcium channel blockers was noted, from 36% in 1986-1988 to 17% in 1994. The increase in the prescription of beta-adrenergic blocking agents was especially remarkable in the subgroups for which a larger underuse was recorded in the previous study, such as the elderly. The proportion of patients prescribed an ACE inhibitor increased from 14% in 1989-1991 to 23% in 1994. In a multivariate analysis the prescription of ACE inhibitors was associated with female gender, hypertension during admission, heart failure during admission, and previous myocardial infarction. A substantial increase in the prescription of beta-adrenergic blocking agents and acetylsalicylic acid and a decrease in the prescription of calcium channel blockers was recorded between 1982 and 1994. The prescription rate of beta-adrenergic blocking agents has increased substantially in certain subgroups where underuse had been previously recorded. Most of the changes occurred in 1989-1991, and reached a steady state in 1994. In 1994 an increase in the prescription of ACE inhibitors was also recorded.

European network for the case-population surveillance of rare diseases (Euronet). A prospective feasibility study

OBJECTIVE

Euronet, a case-population surveillance scheme, aims to estimate the risk of certain rare conditions which are commonly iatrogenic, by comparing drug use amongst non-selective cases with overall drug use in the general population.

METHODS

The method is based on three provisos: (1) all incident cases (irrespective of suspected aetiology) should be ascertained and studied; (2) a full drug history should be obtained from cases by direct interview; and (3) drug-use data for the products of interest should be available for this population from which cases are chosen. The feasibility of this problem-oriented approach for the identification of new signals of adverse drug reactions and for risk estimation will be tested in relation to agranulocytosis, Stevens-Johnson syndrome and toxic epidermal necrolysis in four defined areas in Europe, totalling 19 x 10(6) inhabitants, with these latest two outcomes being studied in only three regions. The design, methods and main limitations of this case-population surveillance approach are described.

From clinical trials to clinical practice: oral anticoagulation among patients with non-rheumatic, atrial fibrillation

OBJECTIVES

The aim of the present study was to evaluate the impact of the results of clinical trials on the prophylactic treatment of non-rheumatic atrial fibrillation with oral anticoagulants.

METHODS

Retrospectively, we studied a random sample of 375 patients discharged from our hospital with a diagnosis of non-rheumatic atrial fibrillation between 1991 and 1993. Information about diagnoses, other clinical variables and treatments prescribed at discharge was obtained from the hospital medical records.

RESULTS

During the whole study period, 14% of patients were prescribed an oral anticoagulant agent and 17% were prescribed acetylsalicylic acid. A non-significant increase in the proportion of patients prescribed oral anticoagulant drugs, from 9% to 17%, was observed. Multivariate analysis showed that a history of stroke (OR = 5.96) and younger age were significantly associated with the prescription of oral anticoagulants. ASA prescription was strongly associated with a history of concomitant vascular disease (OR = 5.8), but not with other risk factors for stroke. Sixty-five percent of patients had one or more risk factors for stroke, did not present any contraindications to anticoagulant agents, but nevertheless were not prescribed one of these drugs.

CONCLUSIONS

Anticoagulant agents and acetylsalicylic acid were largely underprescribed to patients with non-rheumatic atrial fibrillation, and oral anticoagulants were not prescribed according to the individual patients' risk of stroke.

[Utilization of thrombolytic drugs in Barcelona. Study Group on Secondary Prevention of Myocardial Infarction]

BACKGROUND

A number of clinical trials including more than 50,000 patients have shown the efficacy of thrombolytic therapy in reducing mortality associated with acute myocardial infarction (AMI). However, the results of some recently published drug utilization studies have shown that only one third of admitted patients with a diagnosis of AMI receive thrombolytic treatment. The aim of the present study was to quantify and characterize the use of thrombolytic drugs in three hospitals in Barcelona, Spain.

PATIENTS AND METHODS

We collected retrospective information about some clinical variables and drug prescription of patients discharged with a diagnosis of AMI from three hospitals in Barcelona between January and June 1994.

RESULTS

Three hundred and sixty-four patients (247 men, 68%) with a mean age of 68 years (SD 13) were included in the study. The median time from the beginning of clinical symptoms to hospital admission was 3 h (range 1 to 96). One hundred and two patients (28%) were prescribed thrombolytic drugs, and of these, 62%, received streptokinase. No one patient received any thrombolytic treatment before hospital admission. In a multivariate analysis the following variables were negatively associated with thrombolytic use: age over 75 years, more than three hours from the beginning of symptoms to hospital admission and an EKG with bundle-branch block, ST depression or normal. After excluding patients with limitations to thrombolytic use, 18% of all patients could be identified who did not receive any thrombolytic treatment they could have benefited from.

CONCLUSIONS

Only one third of admitted patients with a diagnosis of AMI in the three study hospitals receive thrombolytic treatment. One fifth of the study population with AMI does not receive any thrombolytic therapy but could have benefited from it.

[Analgesics in the postoperative period of abdominal interventions. The Study Group on Postoperative Analgesia of the Spanish Society of Clinical Pharmacology]

BACKGROUND

Analgesics can avoid postoperative pain. The aim of this study was to evaluate their prescription after abdominal surgery.

PATIENTS AND METHODS

Prospective study including patients who had undergone abdominal surgery in two hospitals in Barcelona, in 1993. Prescription and administration of analgesic drugs, and pain severity during the first 48 hours of the postoperative period were evaluated.

RESULTS

One hundred and sixty-four patients (83 men) were included. The most frequently prescribed drugs were metamizol (111; 68%), pethidine (83, 51%), and diclofenac (44; 27%). A high percentage of analgesic prescriptions on an "as needed" basis was recorded. Administered doses were lower than those recommended, and lower than those prescribed. Fifty-three percent of patients suffered significant pain during the first day.

CONCLUSION

A too low proportion of analgesic drugs is prescribed in a predetermined schedule, in contrast to "as needed" prescription. Opiate derivatives are underused. All analgesic drugs are prescribed at inadequate dosage. This prescription pattern is associated with a high prevalence of postoperative pain.

A randomized, double-blind, placebo-controlled trial comparing pethidine to metamizol for treatment of post-anaesthetic shivering

1. Shivering is frequent during the post-anaesthetic recovery period, and there is no clear consensus about the best strategy for its treatment. We tested the efficacy of two commonly used analgesic drugs, pethidine and metamizol. 2. A randomized, double-blind, placebo-controlled clinical trial was performed, including 104 adult patients who presented with post-anaesthetic shivering during the recovery from general anaesthesia. They were randomized to receive placebo (n = 32), metamizol 25 mg kg-1 (n = 37), or pethidine 0.4 mg kg-1 (n = 35). The response to treatment was assessed 5, 15 and 45 min after drug administration, and the main outcome variable was complete suppression of shivering. 3. The efficacy at 5, 15 and 45 min was as follows: placebo 6%, 16% and 37%; metamizol 13.5%, 32% and 76%, and pethidine 89%, 91% and 89%. With both active drugs the efficacy at all three time intervals was significantly higher than that with placebo (P < 0.05). The differences (at 5 and 15, but not at 45 min) between pethidine and metamizol were statistically significant (P < 0.05). Both drugs were well tolerated. 4. The persistence of shivering at 45 min in two thirds of placebo-treated patients indicates that drug treatment is worthwhile; metamizol produces a better postanaesthetic shivering response than placebo, especially 15 and 45 min after drug administration; the efficacy of pethidine was the highest and the response to it appeared more quickly; however, at 45 min it was similar to that observed with metamizol. 5. Both metamizol and pethidine suppress postanaesthetic shivering, but the latter induces a quicker and more reliable response.

Clinical trials versus clinical practice in the secondary prevention of myocardial infarction

To examine whether the results of trials on the secondary prevention of myocardial infarction have led to a change of prescription practice, the discharge forms of a random sample of 737 patients admitted to a university hospital with a diagnosis of acute myocardial infarction (MI) with Q wave from 1982 to 1988 were examined. Information about cardiovascular and other risk factors, contraindications, and prescription of beta-adrenoceptor antagonists (beta AA), acetylsalicylic acid (ASA) and calcium channel blockers (CCB) was collected. The prescription of these drugs was analysed in relation to clinical variables and the date of patients' discharge from hospital. During the 7 years of follow-up, the prescription of beta AA increased gradually from 20% to 30-35%; the prescription of CCB was above 30% during the same period and did not change significantly with time. The prescription of ASA increased from 0% to 30-35% in the last 3 years of follow-up. Contraindications to beta AA were present in 23.2% of cases and contraindications to ASA in 14.4%. In a multivariate analysis, hypertension (odds ratio 2.29, 95% confidence interval 1.55-3.38) and the period 1986-1988 (OR 2.27, 95% CI 1.57-3.30) were associated with the prescription of beta AA, although the prescription of beta AA decreased significantly with advancing age. Other variables inversely associated with the prescription of beta AA were contraindications (OR 0.41, 95% CI 0.24-0.66) and the presence of heart failure during admission (OR 0.08, 95% CI 0.03-0.20).(ABSTRACT TRUNCATED AT 250 WORDS)

Multicentre hospital drug utilization study on the prophylaxis of venous thromboembolism. The Venous Thromboembolism Study Group of the Spanish Society of Clinical Pharmacology

1. Thromboembolic disease (TED) is an important cause of in-hospital morbidity and mortality. Although different prophylactic approaches have been shown to be effective and cost-effective, surveys have suggested that they are underused. The aim of this study was to estimate the prevalence of use of TED prophylaxis in our hospitals. 2. All patients admitted on a specified day to the Internal Medicine and General Surgery wards of seven Spanish university hospitals were included in the study. They were identified cross-sectionally and followed up until discharge or for 15 days. Information about the following variables was collected: risk factors for venous thromboembolism, prophylactic measures used (if any), contraindications to the use of each specific drug or other prophylactic measure, and dosage schedule of the drug used, if any. 3. Nine hundred and thirty-nine patients (53% men) were studied. The most common risk factors for venous thromboembolism were: age > or = 40 years (802; 85%), major surgery (298; 32%), immobilization > or = 6 days (285; 30%), obesity (241; 26%), and cancer (202; 22%). 4. Prophylactic measures were used in 320 patients (34%). Of these, 297 (93%) received heparin, mainly as low molecular weight heparins (248, 78%); physical measures were rarely used. 5. Five hundred and eighty-three patients (62%) fulfilled criteria for moderate or high risk of venous thromboembolism; only 275 (47%) of them received any form of prophylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)

[The use of antibiotics in surgical prophylaxis. The characteristics and consequences]

BACKGROUND

The efficacy of antibiotic prophylaxis in certain surgical procedures has been demonstrated in clinical trials. The present study aimed at getting knowledge on the way how it is used in a certain hospital.

METHODS

In a certain day, all patients receiving antibiotics to prevent a postoperative infection were identified in a medical school hospital. Information on the operative procedure, prescribed antibiotics and clinical course of the patients was recorded.

RESULTS

Out of 714 patients admitted, 255 (36%) were treated with antibiotics and, of these, 85 were given them to prevent a postoperative infection. In 52% of patients, two or more antibiotics were given. The mean (SD) duration of prophylaxis was 8.4 (8.6) days. It was judged as really indicated in 34 cases (40%). Only in 17 (20%) the first choice antibiotic was selected; in 11 (13%) a preoperative dose of the right antibiotic was administered and only in 3 (3.5%) a preoperative dose of the first choice antibiotic was administered and prophylaxis lasted up to 48 hours.

CONCLUSIONS

The use of antibiotics in surgical prophylaxis in a medical school hospital is inappropriate in more than 95% of cases. The situation in other centres should be quantified and the universally accepted norms of prophylaxis should be implemented.

Therapeutic consultation: a necessary adjunct to independent drug information

1. A therapeutic consultation service was implemented in 1984 to complement other methods of information and education on drug therapy for prescribers. 2. Up to 1991, 1,620 enquiries were received, 65% from our hospital and an increasing proportion from primary care (10%), other hospitals (6%), family planning centres (4%), and other sources (14%). 3. More than two-thirds (67%) were consultative enquiries, as opposed to demands for factual information, which needed knowledge of medical aspects of the case and clinical expertise. 4. 85% of enquiries were answered with a written report including relevant references and as conclusive as possible recommendations. 5. More discussion of therapeutic consultation is needed, and aspects for discussion are suggested.

Adverse drug reactions leading to hospital admission

This article describes the implementation of a simple method of drug surveillance set up at a hospital emergency ward. From a total of 48,678 patients admitted, the medical records of those presenting with one or more of a pre-established list of admission diagnoses (n = 7728; 15.8%) were checked. Of these 554 (1.1%) were diagnosed as experiencing an adverse drug reaction. When the medical record suggested an adverse drug reaction, drugs taken before admission were ascertained by interviewing the patients with a structured questionnaire. After excluding upper gastrointestinal bleeding (226 cases) and certain bone marrow blood dyscrasias (42 cases), 286 patients with drug-induced events leading to hospital admission were identified in 2 years. Fatal adverse drug reactions, previously undescribed reactions, and some specific examples, such as digoxin-amiodarone interaction, drug-induced pancreatitis, nicardipine-induced AV block, severe skin reactions, and NSAID-induced bronchospasm, are described. Basically, this method consists of assembling series of cases systematically, and is therefore devoid of selective bias. In addition, it allows a more in-depth clinical and anamnesic study of specific diseases, as compared with voluntary reporting.

[The use of the determination of plasma theophylline concentrations in the hospital]

BACKGROUND

The evaluation of the determination of plasmatic concentrations of theophylline (PCT) in clinical practice is scarce. An observational study was carried out with the aim of discerning the reasons why PCT determinations are requested, the theophyllinemias obtained and the attitude of the medical staff in a hospital.

METHODS

PCT determinations obtained in 113 patients over a period of 3 months were analyzed. Information concerning treatment and daily doses of theophylline, reasons for theophylline determination, apart from those included in the request for theophyllinemia determination, clinical history and treatment sheets were collected.

RESULTS

Treatment with theophylline had been indicated in 78 patients (69%) with chronic bronchitis, and 30 (26%) with asthma. All the patients received medication in addition to theophylline. Daily dosage (SD) was 734 (260) mg and the daily doses as to body weight (SD) was 11 (4) mg/kg/day. 188 DNPT were performed, however 22 (12%) were inadequate; of the remaining 166 PCT determinations 117 (69%) had been requested with no indication of insufficient clinical response, suspicion of undesirable effects or modifying factors of the pharmacokinetics of theophylline. The mean plasmatic concentration (SD) was 11.3 (7) micrograms/ml. PCT was infratherapeutic in 74 PCT determinations (44%), therapeutic in 73 (44%) and toxic in 19 (11%). Therapeutic concentrations were obtained in only 16 (35%) of the 45 patients in whom a second PCT determination had been carried out.

CONCLUSIONS

In this study scarce individualization in the indication of treatment and the doses of theophylline administered are observed. The reason for soliciting determination of theophyllinemia and dosage adjustment in terms of plasmatic concentrations are also commented upon.