Self-prescribed laxative use: a drug-utilization review

Laxative Use in the Community: A Literature Review

Laxatives are widely available without prescription and, as a consequence, they are commonly used for self-management of constipation by community-dwelling adults. However, it is not clear to what extent laxatives are used. Nor is it clear how laxatives are chosen, how they are used and whether consumers are satisfied with their performance. This review of published literature in the last 30 years shows the prevalence of laxative use in community-dwelling adults varied widely from 1% to 18%. The prevalence of laxative use in adults with any constipation (including both chronic and sporadic constipation) also varied widely from 3% to 59%. Apart from any geographical differences and differences in research methodologies, this wide range of estimated prevalence may be largely attributed to different definitions used for laxatives. This review also shows that laxative choice varies, and healthcare professionals are infrequently involved in selection. Consequently, satisfaction levels with laxatives are reported to be low and this may be because the laxatives chosen may not always be appropriate for the intended use. To improve constipation management in community and primary healthcare settings, further research is required to determine the true prevalence of laxative use and to fully understand laxative utilisation.

Missed Opportunity to Deprescribe: Docusate for Constipation in Medical Inpatients

BACKGROUND

Hospital admissions provide an opportunity to deprescribe ineffective medications and reduce pill burden. Docusate sodium is a stool softener that is frequently prescribed to treat constipation despite poor evidence for efficacy, thus providing a good target for deprescription. The aims of this study were to characterize rates of use and discontinuation of docusate among internal medicine inpatients, as well as use of other laxatives.

METHODS

We conducted a retrospective observational study over 1 year on all patients admitted to internal medicine at 2 urban academic hospitals to determine rates of docusate use. We also evaluated laxative and opioid medication use on a random sample of 500 inpatients who received docusate to characterize patterns of prescription and deprescription.

RESULTS

Fifteen percent (1169/7581) of all admitted patients received 1 or more doses of docusate. Among our random sample, 53% (238/452) received docusate before admission, and only 13% (31/238) had docusate deprescribed. Among patients not receiving docusate before admission, 33.2% (71/214) received a new prescription for docusate on discharge. Patients receiving opioids were frequently prescribed no laxatives or given docusate monotherapy (28%, 51/185).

CONCLUSIONS

Docusate was frequently prescribed to medical inpatients despite its known ineffectiveness, with low deprescription and high numbers of new prescriptions. Docusate use was common even among patients at high risk of constipation. One third of patients not receiving docusate before admission were prescribed docusate on discharge, potentially exacerbating polypharmacy. Among patients already receiving docusate, 80% had it continued on discharge, indicating significant missed opportunities for deprescribing. Given the availability of effective alternatives, our results suggest that quality-improvement initiatives are needed to promote evidence-based laxative use in hospitalized patients.

Selection bias in pharmacy-based patient surveys

PURPOSE

To evaluate if there is a selection bias in drug utilization surveys on prescription drugs regularly conducted in Swedish pharmacies, to describe the direction of this potential bias and discuss the implications for the results.

METHODS

Age and gender distributions within patient survey samples from drug utilization surveys conducted during 2006-2010 are compared to the age and gender distribution of all Swedish patients, receiving the same drug or drugs, as given by the Swedish Prescribed Drug Register. The differences between the proportions of patients within the age and gender segments of each pair of survey/register data were calculated.

RESULTS

In 25 (81%) out of 31 included surveys, patients aged 75 years or older are significantly underrepresented, as they are less likely to visit the pharmacy to collect their prescription drugs themselves and thus disqualify for the interviews. Data on women show similar results as overall survey data, whereas the underrepresentation of the oldest age group among men appears in a lower proportion of the surveys, 67%. The general consequence is a selection towards a healthier survey sample, but the consequences in the individual surveys vary, depending on what drug is being studied.

CONCLUSION

Pharmacy-based patient surveys provide a convenient data collection method for patient self-reported data, but patients aged 75 years or older are consistently underrepresented. In surveys where this may influence the main research question, data should also be collected with other methods reaching the oldest patients.

Exposure to sennoside-digoxin interaction and risk of digoxin toxicity: a population-based nested case-control study

AIMS

Digoxin is an important medication for heart failure (HF) patients and sennosides are widely used to treat constipation. Recently, safety concerns have been raised about a possible interaction between sennosides and digoxin, an issue that has not been studied empirically. This study therefore aimed to evaluate whether exposure to sennoside-digoxin interaction is associated with an increased risk of digoxin toxicity.

METHODS AND RESULTS

This was a population-based nested case-control study that analysed data obtained from the Taiwan National Health Insurance Research Database between 1 January 2001 and 31 December 2004. All HF patients treated with digoxin for the first time were included as the study cohort. Of these, cases were identified as subjects hospitalized for digoxin toxicity (International Classification of Diseases, Ninth Revision, Clinical Modification, ICD-9-CM 972.1), and matched to randomly selected controls. Use of sennosides was compared between the two groups. Odds ratios (ORs) were employed to quantify the risk associated with exposure to sennoside-digoxin interaction by conditional logistic regression. The study cohort comprised 222,527 HF patients, of whom 524 were identified as cases and 2,502 as matched controls. Use of sennosides during the 14 days preceding the index date was found to be associated with a 1.61-fold increased risk of digoxin toxicity [95% confidence interval (CI) = 1.15, 2.25]. Additionally, a greater risk was observed for sennosides prescribed at an average daily dose ≥ 24 mg (adjusted OR = 1.93; 95% CI = 1.27, 2.94).

CONCLUSION

The combined use of sennosides and digoxin was found to be associated with a modest increased risk of digoxin toxicity in HF patients.

Current and future therapies for chronic constipation

In this article, traditional and novel therapies for chronic constipation are reviewed. Traditional laxatives are effective at inducing bowel movements, but efficacy in long-term management and efficacy on constipation-associated abdominal symptoms are less well established, with the exception of polyethylene glycol, for which long-term studies confirm sustained efficacy. Recently approved drugs include the colonic secretagogue lubiprostone and the 5-HT4 agonist prucalopride. In controlled trials in chronic constipation, these drugs were shown to significantly improve constipation and its associated symptoms, with a favourable safety record. Methylnaltrexone, a subcutaneously administered peripherally acting mu opioid receptor antagonist, has recently been approved for opioid-induced constipation in terminally ill patients. New agents under evaluation include the 5-HT4 agonists velusetrag and naronapride, the guanylate cyclase-C receptor agonist linaclotide and the peripherally acting mu opioid receptor antagonist alvimopan.

A composite screening tool for medication reviews of outpatients: general issues with specific examples

Regular performance of medication reviews is prominent among methods that have been advocated to reduce the extent and seriousness of drug-related problems, such as adverse drug reactions, drug-disease interactions, drug-drug interactions, drug ineffectiveness and cost ineffectiveness. Several screening tools have been developed to guide practising healthcare professionals and researchers in reviewing the medication patterns of elderly patients; however, each of these tools has its own limitations. This review discusses a wide range of general prescription-, treatment- and patient-related issues that should be taken into account when reviewing medication patterns by implicit screening. These include generic and therapeutic substitution; potentially superfluous or inappropriate medications; potentially inappropriate dosages or duration of treatment; drug-disease and drug-drug interactions; under-treatment; making use of laboratory test results; patient adherence, experiences and habits; appropriate dosage forms and packaging. A broad selection of specific examples and references that can be used as a basis for explicit screening of medication patterns in outpatients is also offered.

Predictive factors of self-medicated drug use among the Spanish adult population

PURPOSE

Our study aimed at describing the prevalence of self-medicated drug use among the Spanish adult population and to identify the predictive factors of such self-medication in Spain.

METHODS

Descriptive, cross-sectional study covering the Spanish adult population, using data drawn from the 2003 Spanish National Health Survey (ENSS). A total of 19 514 subjects were analysed. The independent variables were socio-demographic and health-related, and the dependent variable was self-medicated drug use. Using logistic multivariate regression models we have estimated the independent effect of each of these variables on the self-medicated consumption.

RESULTS

The 18.1% of all Spaniards indulge in self-medication. Our study shows that 45% of all cold and influenza medication and 39.4% of analgesics consumed by the population involve self-medication. It should be stressed here that 17.7% of persons who took antibiotics did so in the form of self-medication. The variables that were independently and significantly associated with a greater probability of self-medicated consumption were: sex; lower age; higher educational level; consumption of alcohol; smoking habit; use of alternative medical products; absence of chronic disease and a positive perception of health.

CONCLUSIONS

In Spain, the prevalence of self-medicated drug use is higher in women than men. In our population, the influence of unhealthy lifestyles, such as alcohol and tobacco consumption, is related to a higher likelihood of self-medication.

Are herbs always good for you? A case of paralytic ileum using a herbal tisane

We believe that administration of phytotherapics ('herbal' medicines) should be managed by physicians and pharmacists who can monitor any adverse reactions including allergies in patients. This of course implies that physicians and pharmacists require adequate training at the university and post-university level regarding all aspects of medicinal plants. We report here a case of paralytic ileum occurring in an older self-medicated patient who acquired an herbal tisane composed of Cassia angustifolia, as well as other plant products, in an herbal shop, for chronic constipation.