Nature and frequency of prescription modifications in community pharmacies: A nationwide study in the Netherlands.

AIMS: To investigate the nature and frequency of prescription modifications in Dutch community pharmacies. METHODS: In this cross-sectional study, Dutch community pharmacists documented prescription modifications in their pharmacy during 1 predetermined day. Pharmacists from all Dutch community pharmacies were invited to participate. A prescription modification was defined as any modification in a prescription for a medicine or other healthcare product because of an administrative problem, logistic issue or potential drug-related problem (DRP). All documented modifications were assessed to establish the nature and frequency of prescription modifications. RESULTS: Pharmacists in 275 pharmacies completed the study. A modification was performed in 5.5% of all prescriptions. 1.3% of the prescriptions contained an administrative problem, of which insufficient specification of the dosing regimen was most common (63.1%). A modification was performed due to a logistic issue in 2.4% of the prescriptions. The most frequently recorded issues were unavailability of medication (40.9%) and obligatory product substitutions due to reimbursement policies (33.2%). A modification was performed in 1.8% of the prescriptions to solve or prevent potential DRPs. Of these, 69.2% was potentially clinically relevant according to the pharmacist concerned. The most frequently prevented potential DRP was an incorrect strength or dose (31.9%). CONCLUSION: Dutch community pharmacists modified almost 1 in 20 prescriptions per pharmacy. The nature of the modifications reflects current community pharmacy practice, in which pharmacists frequently deal with logistic issues and intervene to solve or prevent for DRPs several times a day. The majority of the DRPs were considered to be potentially clinically relevant.

Prevalence and determinants of pharmacy shopping behaviour.

BACKGROUND AND OBJECTIVE: Discontinuity of care bears the risk of medication errors and poor clinical outcomes. Little is known about the continuity of care related to pharmacies. Therefore, we studied the prevalence and determinants of pharmacy shopping behaviour in the Netherlands. METHODS: Beneficiaries from a Dutch pharmacy claims database who had visited two or more pharmacies in 2001 were indicated as 'shoppers' (n = 45 805). A random sample was taken from all the other beneficiaries who had received at least one prescription: 'non-shoppers' (n = 45 805). Shoppers were classified as light (all patients who visited more than one pharmacy at least once in 2001, except for patients defined as heavy or moderate shoppers), moderate (visited 3 or 4 pharmacies and had proportion of prescriptions elsewhere >10% and number of prescriptions elsewhere >10) or heavy (visited 5 or more pharmacies and had proportion of prescriptions elsewhere >10% and number of prescriptions elsewhere >10). Determinants of shopping behaviour were investigated as well as the association between any dispensing of Anatomical Therapeutic Chemical (ATC) classes of drugs and this behaviour. RESULTS: 10.8% beneficiaries were identified as shoppers: 98.8%'light shoppers', 1.0%'moderate shoppers' and 0.2%'heavy shoppers'. Female gender [odds ratio (OR)(adj) 1.2; 95% confidence interval (CI) 1.1-1.2], younger age (OR(adj) 1.7; 95%CI 1.7-1.8), the use of > or =3 drugs (OR(adj) 2.9; 95%CI 2.8-3.0) and visiting different kind of prescribers (OR(adj) 2.4; 95%CI 2.4-2.5) were associated with shopping behaviour. Shoppers more frequently received at least one prescription for systemic anti-infectives (51.7% vs. 30.8%; OR 2.4; 95%Cl 2.3-2.5) and for nervous system drugs (46.2% vs. 29.3%; OR 2.1; 95%Cl 2.0-2.1). CONCLUSIONS: Pharmacy shopping behaviour is limited in the Netherlands. However, it may put the patient at risk for unintentional problems, such as drug-drug interactions with anti-infectives. A small proportion of patients exhibit possibly intentional shopping behaviour with psychotropic drugs.

Reduction in the therapeutic intensity of abortive migraine drug use during ACE inhibition therapy--a pilot study.

INTRODUCTION: Since a few case reports have demonstrated some beneficial effects of angiotensin converting enzyme (ACE) inhibitors in migraine prevention, we were interested in studying the impact of ACE inhibitors and angiotensin II receptor antagonists (Ang II) on the consumption of specific abortive migraine drugs and, therefore, indirectly on the frequency of migraine attacks. METHODS: Data from a large prescription database involving 95 patients initiating a specific abortive migraine drug (ergotamine or a triptan) and subsequently treated with either an ACE inhibitor or angiotensin receptor antagonist (index group: ACE/Ang II) or diuretic (reference group) were analysed. The effects of ACE/Ang II inhibition as well as diuretic therapy on reducing the frequency of migraine attacks were assessed by measuring the mean consumption of abortive migraine drug use, in DDDs per month ('therapeutic intensity'), before, during and after ACE/Ang II or diuretic therapy. A 'therapeutic fluctuation intensity estimate' of abortive migraine drug use for all patients was likewise calculated. RESULTS: On an individual level, the therapeutic intensity (TI) fluctuation estimate, 'during' relative to 'before' ACE diuretic therapy, was significantly larger for the ACE/Ang II group (62% reduction) than for the diuretic group (24% reduction) (p = 0.02). For patients who continued abortive migraine drug use during and after ACE/Ang II or diuretic therapy, a significantly larger reduction in this estimate was observed during ACE/Ang II inhibition (68.9%) compared to during diuretic therapy (10.5% increase) (p = 0.004). The TI fluctuation estimate, after relative to 'during', had increased by 50.3% after ACE/Ang II inhibition and had reduced by 22.2% after diuretic treatment (p = 0.1). CONCLUSIONS: A clear reduction in the TI of abortive migraine drug use during the use of ACE inhibitors as compared to diuretic treatment was observed. Our findings may indirectly support a positive effect of ACE/Ang II inhibition on the frequency and severity of migraine attacks, as observed in other studies and reports.

Incidence and determinants of antidepressant drug use in migraine patients.

The purpose of this retrospective, follow-up study was to characterise the use of antidepressant medication in a defined migraine population and evaluate the determinants thereof. Data was obtained from the PHARMO-RLS prescription database. Our migraine population (2,517 people) included patients having commenced specific migraine drugs, ergotamine or sumatriptan, for the first time from January 1 1992 to December 31 1998. The corresponding date was termed the 'index date'. Non-migraine patients, those not having used any medication specific for migraine, were selected and equally matched (n=2,517). The cumulative incidence of initiating antidepressant treatment was estimated during two-year observation periods prior to and after the index date. Several demographic and comedication characteristics were assessed as potential determinants of antidepressant drug use within the migraine population. Other determinants included usage patterns ("therapeutic intensity") of ergotamine and sumatriptan, defined as the absolute number of Defined Daily Doses (DDDs) dispensed per patient during one year prior to initiation of antidepressant therapy. A total of 300 migraine patients (11.9%) and 213 non-migraine patients (8.5%) had initiated antidepressant treatment in the two-year period prior to or in the two-year period after the index date (RR adj 1.4; 95% CI 1.2-1.7). The cumulative incidence of initiation of antidepressant treatment for the migraine population was 3.0% per year prior to and 3.2% per year after the initiation of specific migraine analgesia. The concomitant use of benzodiazepines (RR adj 4.7; 95% CI 3.5-6.3), migraine prophylactic medication (RR adj 2.1; 95% CI 1.6-2.8) and heavy therapeutic intensity use of specific migraine analgesia, defined as >/=150 DDDs per year were highly predictive of antidepressant drug use within the migraine population. In conclusion, compared to the non-migraine population, the initiation of antidepressant treatment was only slightly higher in the migraine population. A number of determinants within the latter were found to be strongly associated with antidepressant drug use, the nature of which most likely reflects an increased severity of migraine whereby therapeutic needs are higher.

Migraine prophylactic medication usage patterns in The Netherlands.

This study aims to investigate usage patterns of specific migraine prophylactic medications in ergotamine and triptan patients commencing this treatment for the first time during 1 January 1992 until 31 December 1998. Usage patterns of specific migraine prophylactic drugs were evaluated for each patient by accessing data from a large prescription database and were characterized as continued, switch or stop use during the patient observation period. Several patient and medication-related factors were explored in order to identify a possible relationship with the specific usage pattern defined. Approximately 75% of the study population (n = 729) had terminated (stop or switch) prophylactic treatment after 1 year. Age < 40 years (relative risk (RR) 1.9; 95% confidence interval (CI) 1.2-3.2) and the concomitant use of non-steroidal anti-inflammatory drugs (RR 3.2; 95% CI 1.2-5.5) or specific abortive migraine drugs resulted in a faster onset of treatment modification (switch). Overall, migraine prophylactic treatment is used for a relatively short period, probably attributable to the common limitations associated with migraine prophylaxis, such as poor compliance and/or limited therapeutic efficacy. Patterns of use can be influenced by a variety of factors, including age, type of prescriber and certain co-medication. Patient interview studies are required to clarify these issues further.

Single use of sumatriptan: a patient interview study.

OBJECTIVE: To investigate the possible reasons associated with the use of a single prescription of sumatriptan. BACKGROUND: A few population-based studies concerning the usage patterns of sumatriptan have revealed a relatively high incidence (approximately 40%) of sumatriptan users who utilize only a single prescription of the drug. DESIGN AND METHODS: Using automated prescription data from 11 community pharmacies, we identified single and multiple sumatriptan prescription recipients. The data were collected from May 1, 1998, to April 30, 2000. Several patient- and medication-related variables possibly associated with single recipiency of sumatriptan were analyzed. In addition, single recipients of sumatriptan were invited for an interview and asked a number of questions related to their clinical status and their experience with the medication. RESULTS: Four hundred ninety-five, first-time users of sumatriptan were identified during the patient selection period, of whom 38% were single recipients of sumatriptan. Of the latter, 102 patients were considered eligible for interview. Reasons for terminating treatment after only 1 prescription included: inefficacy and/or occurrence of side effects, 78% (n=79); uncertain diagnosis of migraine, 39.2% (n=40); and reduction in headache frequency, 33.3% (n=34). Almost half of the population had terminated treatment without having consulted their physician. More than half relied upon the use of over-the-counter (OTC) analgesics after having tried sumatriptan. Compared to multiple users of sumatriptan, single recipients were far less likely to have used another form of migraine treatment prior to (odds ratio, 0.35; [95% confidence interval, 019 to 0.67]) and after (odds ratio, 0.34 [95% confidence interval, 0.19 to 0.63]) initiating sumatriptan. Furthermore, single recipients had demonstrated an increased tendency towards benzodiazepine use prior to receiving sumatriptan (odds ratio, 1.80 [95% confidence interval, 1.00 to 3.28]). CONCLUSIONS: Single use of a sumatriptan prescription reveals some issues that may impact negatively the provision of effective migraine management. These include: rapidly developing dissatisfaction with the treatment provided and a lower tendency to seek out medical care. Our results also suggest that the drug may be used (inappropriately) as a diagnostic tool.

Incidence and determinants of migraine prophylactic medication in the Netherlands.

OBJECTIVE: To estimate and examine the incidence and determinants of initiation of migraine-prophylactic therapy as well as the corresponding drug of choice over a period of 5 years following the use of specific abortive migraine drugs. METHODS: By accessing data from a large prescription database, an identification of patients treated with ergotamine or a triptan from 1 January 1994 to 31 December 1998 was made. The cumulative incidence of initiation of migraine-prophylactic drugs (beta-blockers, serotonin antagonists, specific calcium antagonists, amitriptyline, clonidine and valproic acid) was estimated in patients following the use of ergotamine or a triptan. An assessment of the migraine-prophylactic drug of first choice was also performed. A few baseline determinants were analysed to highlight a possible association with the initiation of prophylactic therapy: age, gender, type of abortive migraine drug use and year of prophylaxis. Additional determinants included the analysis of drug-utilisation patterns, such as the consumption and switch patterns of abortive migraine drug use as well as co-medication use prior to prophylaxis. For this particular analysis a reference group (patients not having commenced prophylaxis) was selected from the initial study population. RESULTS: After having satisfied eligibility criteria, a total of 3999 first-time users of ergotamine and triptans were included of whom 479 (12%) had initiated migraine-prophylactic therapy. This corresponded to an incidence density of 6.0 per 100 person-years and was highest for patients younger than 45 years and for multiple abortive migraine drug users. The incidence fell considerably from 12.0 person-years in 1994 to 5.1 person-years in 1998. More than half of the patients had been prescribed a beta-blocker as the migraine-prophylactic drug of first choice by both general practitioners and neurologists. The use of antidepressants and/or benzodiazepines and oral contraceptives was significantly higher in patients starting prophylaxis compared with those who did not. The consumption of abortive migraine drug use (4.0 defined daily doses per month vs 3.7 defined daily doses per month), and switch patterns (27.1% vs 30.9%) were similar for patients starting and not starting prophylaxis. CONCLUSION: The overall incidence of initiation of migraine-prophylactic therapy following the use of abortive migraine analgesics was 6.0% per year and fell considerably during 5 years of the study. Beta-blockers were the migraine-prophylactic drugs of first choice for general practitioners and neurologists. In our study we could not determine any factors clearly associated with the initiation of migraine prophylaxis besides prior use of antidepressants and benzodiazepines. A future assessment of the usage patterns of migraine-prophylactic drugs may provide detailed information concerning the effectiveness and tolerability.

Laxative prescribing in relation to opioid use and the influence of pharmacy-based intervention.

INTRODUCTION: Opioid-induced constipation is a common problem and can cause serious complications. It is widely advised that laxatives should be started concurrently with opiates, unless there is a clear indication not to do so. OBJECTIVE: This study was undertaken to estimate how often laxatives were started concurrently with opiates and to describe the effect of pharmacy-based interventions to promote the use of laxatives in patients starting opioids. METHODS: Twenty-six community pharmacies identified all patients who received a first prescription for a strong opioid during January and February of 1998, 1999 or 2000. Pharmacists collected information on patient, drug and prescriber characteristics (age, gender, use of opiates and laxatives). A separate questionnaire was used to collect data on pharmacy-based interventions to promote the simultaneous prescribing of laxatives with the opiates. RESULTS: Overall, 37% of the patients receiving an opioid started taking laxatives within 5 days. The percentage of patients who received laxatives simultaneously with opioids increased from 31% in 1998 to 35% in 1999 and 42% in 2000. In 117 (43%) of the opioid prescriptions, pharmacy-based intervention had taken place before the prescription date. Of these, 48.7% was accompanied by a laxative. Opioid prescriptions (n=152) without a pharmacy based intervention were accompanied in 27.6%. After adjustment for covariates (including time trends), pharmacy-based intervention increased the probability of concomitant laxative use 1.9 [95% CI 1.1-3.3] times. DISCUSSION: This study shows that the widely used guideline to start a laxative when prescribing an opioid is not always followed in daily practice. In addition, we showed that pharmacy-based intervention contributed to increasing laxative use in patients receiving opioids.

Reduction in the intensity of abortive migraine drug use during coumarin therapy.

OBJECTIVE: To investigate the impact of coumarin therapy on migraine attack frequency. BACKGROUND: Sporadic case reports and clinical studies have described beneficial effects of coumarin therapy on migraine severity. DESIGN AND METHODS: A retrospective follow-up study based on a prescription database covering a population of 450 000 was conducted. All patients using an abortive migraine drug (ergotamine or sumatriptan) and subsequently treated with either coumarin (index group) or low-dose acetylsalicylic acid (control group) were analyzed. The impact of coumarin and low-dose acetylsalicylic acid on the frequency of migraine attacks was assessed by measuring the intensity of ergotamine and sumatriptan use, in defined daily doses per month per patient, before and during coumarin or acetylsalicylic acid treatment. In addition, a "therapeutic intensity reduction" was determined for each patient. RESULTS: The study population consisted of 92 patients; 35% had been prescribed coumarin and 65% had been prescribed low-dose acetylsalicylic acid after the initiation of ergotamine or sumatriptan. Two thirds of the study population was treated with ergotamine. Overall, ergotamine and sumatriptan use for the coumarin cohort decreased from 6.4 defined daily doses per month prior to coumarin treatment to 3.0 defined daily doses during coumarin treatment, compared with a reduction from 5.2 defined daily doses per month to 4.4 defined daily doses per month for the low-dose acetylsalicylic acid cohort (P>.05). The therapeutic intensity of ergotamine and sumatriptan use was significantly decreased by 40% for the coumarin cohort, compared with 4.7% for the low-dose acetylsalicylic acid cohort (P=.004). CONCLUSIONS: We observed that coumarin treatment was clearly associated with a reduction in the therapeutic intensity of abortive migraine drug use in comparison with low-dose aspirin treatment. This suggests that, overall, the coumarin cohort had experienced a substantial reduction in the frequency of migraine attacks during anticoagulation treatment. Our findings, as well as those of others, justify a controlled clinical trial to further establish the effects of coumarin therapy on migraine severity and its possible role in the prophylactic management of patients suffering from migraine.

Nature, frequency and determinants of prescription modifications in Dutch community pharmacies.

AIMS: To examine the nature, frequency and determinants of prescription modifications in Dutch community pharmacies. METHODS: A prospective case-control study comparing modified prescriptions with nonmodified prescriptions was carried out in 141 Dutch community pharmacies. 2014 modified prescriptions (cases), collected in the selected pharmacies on a predetermined day in a specific period (25th February until 12th March 1999) and 2581 nonmodified prescriptions (controls) randomly selected on the same day were studied. The nature and frequency of prescription modifications and patient, drug and prescriber related determinants for a modified prescription were assessed. RESULTS: The overall incidence of prescription modifications was 4.3%, with a mean of 14.3 modifications per pharmacy per day. For prescription only medicines (POM) the incidence was 4.9%. The majority of POM modifications concerned a clarification (71.8%). In 22.2% a prescription could potentially have had clinical consequences when not altered; in more than half of the latter it concerned a dose error (13.7% of all cases). POM prescriptions of patients of 40-65 years had a significantly lower chance of modification compared with those of younger people (OR = 0.74 [0.64-0.86]). With respect to medication-class, we found a higher chance of POM modifications in the respiratory domain (OR = 1.48 [1.23-1.79]) and a decreased chance for nervous system POMs (OR = 0.71 [0.61-0.83]). With regard to prescriber-related determinants modifications were found three times more often in non printed prescriptions than in printed ones (OR = 3.30 [2.90-3.75]). Compared with prescriptions by the patient's own GP, prescriptions of specialists (OR = 1.82 [1.57-2.11]), other GP's (OR = 1.49 [1.02-2.17]) and other prescribers such as dentists and midwives (OR = 1.95 [1.06-3.57]) gave a higher probability of prescription modifications. When a GP had no on-line access to the computer of the pharmacy the chance of a modification was also higher (OR = 1.61 [1.33-1.94]). Multivariate analysis revealed that a nonprinted prescription was the strongest independent determinant of prescription modifications (OR = 3.32 [2.87-3.84]), remaining so after adjustment for GP computer link to the pharmacy and for type of prescriber. CONCLUSIONS: At least 30% of Dutch community pharmacies corrected 2.8 POM prescriptions per pharmacy per working day, which could potentially have had clinical consequences if not altered. If the study sample is representative for The Netherlands, Dutch community pharmacies correct a total of approximately 4400 of these prescriptions per working day. Using computerized systems to generate prescriptions is an important strategy to reduce the incidence of prescription errors.

Patterns of ergotamine and sumatriptan use in the Netherlands from 1991 to 1997.

The objective of this study was to assess usage patterns of ergotamine and sumatriptan over a period of 6 years, primarily to evaluate the impact that sumatriptan has had on the prescription of ergotamine. This study used ergotamine and sumatriptan prescription data representing inhabitants of eight cities in the Netherlands and covering the period of 1991-1997. The yearly incidence of new users between 1991 and 1997 was estimated for both drugs as well as for the drug of first choice to be prescribed to patients initiating specific abortive migraine treatment with either ergotamine or sumatriptan. Intra-individual ergotamine and sumatriptan usage patterns, characterized by single (incidental), continuous (rate of retention) or switch use, were examined for five patient cohorts, each for a follow-up period of 1 year. During the year of sumatriptan introduction (1991-1992), the overall incidence of new use for both drugs was highest (5.4 per 1000 inhabitants). Hereafter, a substantial reduction of more than 50% was observed. From 1992 to 1996, the yearly incidence of ergotamine first-time use was significantly higher than that of sumatriptan and up to 1996 ergotamine was more than twice as likely than sumatriptan to be prescribed to patients initiating specific abortive treatment. Hereafter, sumatriptan was as likely as ergotamine to be prescribed as the drug of first choice, which coincided with the full reimbursement of sumatriptan tablets. Overall, neurologists were more likely than general practitioners (GPs), to prescribe sumatriptan as the drug of first choice. Approximately half of the total study population were identified as single-time users. This phenomonen occurred more frequently in the ergotamine cohorts. The sumatriptan cohorts displayed a slight yet significant stronger retention rate compared with the ergotamine cohorts. The overall impact of sumatriptan on ergotamine use in The Netherlands was marginal, predominantly due to GP's adherence to migraine treatment guidelines and reimbursement policies concerning sumatriptan tablets. Overall, incidental use was relatively high and may reflect the reported difficulties in diagnosing migraine, lack of patient-doctor consultation, or that anticipated benefits of the drug were not achieved. Further study is required to clarify these issues.