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Potential Drug Interactions (potential + drug_interaction)

Distribution by Scientific Domains

Medical Sciences	100%

Distribution within Medical Sciences

Pharmacology & Pharmaceutical Medicine	43%
Neurology	12%

Selected Abstracts

Pharmacoepidemiologic study of potential drug interactions in outpatients of a university hospital in Thailand

JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 1 2005
B. Janchawee PhD
Summary Background:, Drug,drug interaction is a potential cause of adverse drug reactions. The incidence of such drug interactions in university hospitals in Thailand is unknown. Purpose:, To estimate the rate of potential drug,drug interactions in outpatients of a typical Thai university hospital, and to identify risk factors for such interactions in Thai patients. Methods:, One-year outpatients' prescription data were retrieved from the hospital computer records. Potential drug interactions were identified using the existing drug-interaction database system. Potential interactions within a specific prescription and involving drugs prescribed 1-, 3- and 7-day earlier were searched for. Possible associations between occurrence of an interaction and a patient's age and gender and the number of items on the prescription were explored. Results:, The overall rate of potential drug interactions was 27·9% with a maximal value of 57·8% at the Department of Psychiatry. The rate of the most potentially significant interactions was 2·6%, being the highest in the Department of Medicine (6·0%), with isoniazid vs. rifampin as the most common interacting combination. The rate increased with the patient's age and prescription size (P = 0·000). The odd's ratio of having at least one potential drug interaction was 1·8 (64·2%) when age increased by 20 years (P = 0·000) and 2·8 (165·7%) when another drug was added (P = 0·000). The rate of potential drug interactions was the same for both genders. The rate of potential drug interactions detected across prescriptions was higher than within prescriptions and was dependent on the time interval between prescriptions. Conclusions:, Potential drug interactions were common in our sample of patients. The rate of such interactions increased with the number of drugs prescribed and the patient's age. [source]

Melatonin and sleep disorders associated with intellectual disability: a clinical review

JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 1 2007
S. G. Sajith
Abstract Background Melatonin is used to treat sleep disorders in both children and adults with intellectual disability (ID), although it has no product license for such use. The evidence for its efficacy, potential adverse effects and drug interactions are reviewed in the context of prescribing to people with ID. Methods A literature search was performed using multiple electronic databases. More literature was obtained from the reference lists of papers gathered through the searches. Results Most of the studies were uncontrolled and the few controlled trials available were of small size. Melatonin appears effective in reducing sleep onset latency and is probably effective in improving total sleep time in children and adolescents with ID. It appears to be ineffective in improving night-time awakenings. Melatonin is relatively safe for short-term use. Its safety for long-term use is not established. Potential drug interactions, possible effects on puberty and concerns regarding the use of melatonin in epilepsy, asthma and depressive disorders are discussed. Conclusions Melatonin appears to be an effective sleep-initiator for children and adolescents with ID and probably has a similar effect for adults. There may be heterogeneity of response depending on the nature of the sleep problem and cause of the ID or associated disabilities. Further studies are necessary before firm conclusions can be drawn and guidelines for the use of melatonin for people with ID formulated. [source]

Frequency of high-risk use of QT-prolonging medications,

PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 6 2006
Nancy M. Allen LaPointe PharmD
Abstract Purpose Prolongation of the QT interval has been associated with increased risk of torsades de pointes and death. Concurrent use of more than one QT-prolonging drug or a QT-prolonging drug with a drug that alters its pharmacokinetic profile is an important risk factor for adverse outcomes. Methods Using a representative sample of 2 million health plan members from 10 health maintenance organizations with pharmacy benefits between January 1999 and July 2001, we identified potential drug interactions involving QT-prolonging medications. Prescription claims overlapping by at least 7 days for either 2 or more QT-prolonging drugs or a QT-prolonging drug with a drug that alters its clearance were considered potential drug interactions. We determined the number of drug interactions overall and the number of these interactions involving patients with other risk factors for torsades de pointes. Results A total of 48,465 potential drug interactions were identified in 10,415 (4.6%) of the 228,550 patients with at least one prescription for a QT-prolonging drug. Amitriptyline was involved in 37,859 (78.1%) of the drug interactions. Of all potential drug interactions, 43,689 (90.1%) occurred in patients with at least one other risk factor for torsades de pointes, and 1053 (2.2%) were listed as a contraindicated combination in product labeling. Conclusion Potential drug interactions involving currently marketed QT-prolonging drugs occurred in 4.6% of patients who had a prescription for a QT-prolonging medication. The findings suggest several areas for targeted interventions to decrease the potential risk from QT-prolonging medications. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Pharmacoepidemiologic study of potential drug interactions in outpatients of a university hospital in Thailand

Effects of non-steroidal anti-inflammatory drugs on the pharmacokinetics and elimination of aciclovir in rats

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2005
Hye-Sun Gwak
This study aims to investigate the effect of commonly used non-steroidal anti-inflammatory drugs (NSAIDs) on the pharmacokinetics and the renal elimination of aciclovir in rats. Pharmacokinetic parameters were determined following an intravenous administration of aciclovir (5 mg kg,1) to rats in the presence and absence of ketoprofen or naproxen (25 mg kg,1). Compared with the control (given aciclovir alone), pre-treatment with ketoprofen or naproxen 30 min before aciclovir administration significantly altered the pharmacokinetics of aciclovir. Renal clearance of aciclovir was reduced by approximately two fold in the presence of ketoprofen or naproxen. Consequently, the systemic exposure (AUC) to aciclovir in the rats pre-treated with ketoprofen or naproxen was significantly (P < 0.05) higher than that from the control group given aciclovir alone. Furthermore, the mean terminal plasma half-life of aciclovir was enhanced by 4,5 fold by pre-treatment with ketoprofen or naproxen. These results suggest that NSAIDs, such as ketoprofen and naproxen, are effective in altering the pharmacokinetics of aciclovir by inhibiting the organic anion transporter-mediated tubular secretion of aciclovir. Therefore, concomitant use of ketoprofen or naproxen with aciclovir should require close monitoring for clinical consequence of potential drug interaction. [source]

Efficacy and Safety of Levetiracetam in Children with Partial Seizures: An Open-label Trial

EPILEPSIA, Issue 5 2002
Tracy A. Glauser
Summary: ,Purpose: To assess the efficacy and safety of levetiracetam (LEV) as adjunctive therapy in children with treatment-resistant partial-onset seizures. Methods: Children (aged 6,12 years) with treatment-resistant partial-onset seizures receiving one standard antiepileptic drug (AED) were eligible. After a 4-week baseline period, children received LEV in a 6-week titration phase (target dose, 40 mg/kg/day) followed by an 8-week evaluation phase. Seizure frequency during the evaluation period with individualized LEV doses (20,40 mg/kg/day) were compared with the 4-week baseline seizure frequency. Plasma concentrations of LEV and other AEDs were determined to evaluate potential drug interactions. Results: Twenty-four subjects enrolled and received LEV; 23 entered the evaluation phase, and 22 completed the evaluation phase. Compared with their baseline seizure frequency, 12 (52%) of 23 subjects entering the evaluation phase had their seizure frequency decrease by >50%. Two subjects remained seizure free during the entire evaluation period. LEV did not significantly affect plasma concentrations of any concomitant AED during this study, and no alteration of mean clinical laboratory values was observed. The most commonly reported adverse events were headache, infection, anorexia, and somnolence. Conclusions: This open-label study of adjunctive LEV therapy (at 20,40 mg/kg/day) suggests that LEV is effective, safe, and well tolerated in children ages 6,12 years with treatment-resistant partial-onset seizures. A randomized, placebo-controlled, double-blind trial of LEV adjunctive therapy in children with treatment-resistant partial-onset seizures is needed and ongoing to confirm these open-label findings. [source]

Shared Mechanisms and Comorbidities in Neurologic and Psychiatric Disorders

HEADACHE, Issue 2001
Stephen D. Silberstein MD
Migraine may be comorbid with several other neurologic and psychiatric conditions, including mood disorders (eg, depression, anxiety, panic disorder), epilepsy, stroke, and essential tremor. Comorbidity presents physicians with opportunities and challenges for both diagnosis and treatment. All diseases must be considered, and therapeutic strategies may need to be modified to avoid potential drug interactions. Comorbidities also may provide clues to the pathophysiologies and any shared mechanisms of the two disorders. Longitudinal studies have demonstrated a bidirectional influence between migraine and major depression, but not between migraine and other severe headache. Migraine is strongly and consistently associated with panic disorder. The risk of migraine in epilepsy is increased particularly in individuals with head trauma, partial seizures, and a positive family history of migraine. The influence is bidirectional. There is also growing evidence of an association between migraine and stroke, particularly among women of childbearing age and individuals who experience migraine with aura. Lastly, a bidirectional association between migraine and essential tremor also exists. These findings suggest that migraine, major depression, epilepsy, and essential tremor share one or more common etiologies. Clinicians should be mindful of them as they design treatment strategies, and also should consider the use of a single pharmacologic agent that is effective for all conditions. [source]

Hepatitis C and human immunodeficiency virus infection

HEPATOLOGY, Issue 5B 2002
424 N. Bond St., David L. Thomas M.D., Suite 10
In the United States, an estimated 200,000 persons are infected with both hepatitis C virus (HCV) and human immunodeficiency virus (HIV). As the lives of HIV-infected persons have been prolonged by use of highly active antiretroviral therapy, liver disease has emerged as an important, and in some settings, the leading cause of morbidity and mortality. Human immunodeficiency virus infection appears to adversely affect all stages of hepatitis C infection, leading to increased viral persistence and accelerated progression of HCV-related liver disease. In turn, hepatitis C may affect the management of HIV infection, increasing the incidence of liver toxicity caused by antiretroviral medications. The medical management of hepatitis C in HIV-infected persons remains controversial, in part because of the complexity of both infections and potential drug interactions, but chiefly because there is so little published information. Nonetheless, the burden of liver disease is too high to delay management of HIV/HCV-coinfected persons while awaiting better data. Instead, the management of hepatitis C today must be based on data generated on persons without HIV and an understanding of both infections. Properly designed studies of therapy in HIV/HCV-coinfected persons are needed to help guide management of these patients in the future. [source]

Hepatitis C and human immunodeficiency virus infection

HEPATOLOGY, Issue S1 2002
David L. Thomas M.D.
In the United States, an estimated 200,000 persons are infected with both hepatitis C virus (HCV) and human immunodeficiency virus (HIV). As the lives of HIV-infected persons have been prolonged by use of highly active antiretroviral therapy, liver disease has emerged as an important, and in some settings, the leading cause of morbidity and mortality. Human immunodeficiency virus infection appears to adversely affect all stages of hepatitis C infection, leading to increased viral persistence and accelerated progression of HCV-related liver disease. In turn, hepatitis C may affect the management of HIV infection, increasing the incidence of liver toxicity caused by antiretroviral medications. The medical management of hepatitis C in HIV-infected persons remains controversial, in part because of the complexity of both infections and potential drug interactions, but chiefly because there is so little published information. Nonetheless, the burden of liver disease is too high to delay management of HIV/HCV-coinfected persons while awaiting better data. Instead, the management of hepatitis C today must be based on data generated on persons without HIV and an understanding of both infections. Properly designed studies of therapy in HIV/HCV-coinfected persons are needed to help guide management of these patients in the future. (HEPATOLOGY 2002;36:S201-S209). [source]

Appropriate use of non-prescription ibuprofen: a survey of patients' perceptions and understanding

INTERNATIONAL JOURNAL OF PHARMACY PRACTICE, Issue 1 2010
Suong N. T. Ngo
Abstract Objectives The aim was to investigate patients' perceptions and understanding on the appropriate use of non-prescription ibuprofen. Methods In this pilot study, a self-administered anonymous survey was completed by 183 patients presenting at one of the eight selected community pharmacy premises in South Australia and the Northern Territory during the study. The questionnaire comprised items on: demographics (age, gender), current medications, frequency of ibuprofen use, medical consultations, reading manufacturer's printed dosage/warning instructions, sources from which drug information was gathered and understanding of common indications for ibuprofen. Key findings Sixty per cent of patients (n= 110/183), predominantly females, were currently on other medications and 64.5% of patients (n= 118/183) did not seek medical advice before using non-prescription ibuprofen. Seventy-one per cent (n= 130) of these patients had used ibuprofen for more than a year. The majority of patients did not provide precise answers for the common indications of ibuprofen. Sixty-six per cent of patients (n= 110) reported rarely or never reading manufacturer's printed warning instructions on the potential drug interactions or adverse effects associated with the use of the product. Conclusions Many patients are unaware that non-presciption analgesics such as ibuprofen can cause potentially serious adverse effects when used in combination with other common medications. [source]

Clinical drug interactions in outpatients of a university hospital in Thailand

JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 6 2005
B. Janchawee PhD
Summary Background:, A clinical event is likely to occur in patients receiving a pair of drugs, that have the potential to cause an interaction. The occurrence of a clinical drug,drug interaction in outpatients of university hospitals in Thailand is unknown. Purpose:, To investigate the occurrence of a clinical event associated with drug,drug interactions in outpatients at a Thai university hospital. Methods:, A case,control study was established. The case was a sample group, randomly selected from a 1-year sample of outpatient prescriptions containing ,significance-1' potential drug,drug interactions, whereas the control was from the same year but with no potential drug interactions. Medical records of the cases and the controls were reviewed for an adverse event (AE) using a newly developed review form. The odds ratio of occurrence of the AE between the cases and the controls was determined. The AE was assessed for its possibility of being caused from a drug,drug interaction. Results:, The most common specific AE in both the cases and the controls was cough. An unplanned revisit to outpatient department or emergency room was found to be the most common general AE. The odds ratio of the occurrence of an AE in the cases, compared with the controls, was 1·495 (95% CI: 0·917,2·438). The possibility that the AEs resulted from drug interactions in the case group was nine ,probable' patients and 15 ,possible' patients, whereas that in the control group was eight ,possible' patients. The most common interacting drug pair was isoniazid,rifampin with an increase in serum hepatic enzymes as the corresponding AE. Conclusions:, Despite outpatients receiving drug pairs with a high potential for adverse interactions, the rate of occurrence of clinical drug interaction events was low. [source]

Pharmacoepidemiologic study of potential drug interactions in outpatients of a university hospital in Thailand

Frequency of high-risk use of QT-prolonging medications,

Latest news and product developments

PRESCRIBER, Issue 5 2007
Article first published online: 16 MAY 200
OFT wants PPRS reform The Office of Fair Trading (www.oft.gov.uk) says reform of the Pharmaceutical Price Regulatory Scheme (PPRS) would allow the NHS to re- invest £500 million in drugs it needs. Its investigation of the 50- year-old PPRS concludes that the scheme does not reflect the therapeutic value of drugs and, while providing a financial safety net for the industry, it mitigates against innovation. The OFT believes drugs should be priced according to their therapeutic value based on their cost effectiveness. Analyses would be fast- tracked for new drugs or, if there are insufficient data, a risk-sharing scheme should be adopted. The ABPI insists that its medicines offer the NHS value for money and believes the OFT's proposal for drug- by-drug pricing would delay access to new medicines. Switching saves money and is problem free Switching to cheaper alternatives within a drug class does not affect the quality of care and offers substantial savings, say UK researchers (Int J Clin Pract 2007;61:15-23). They switched selected patients from atorvastatin (Lipitor) to simvastatin and from losartan (Cozaar) to candesartan (Amias). Exclusion criteria included previous unsuccessful use, poor control of lipids or blood pressure, contraindications and potential drug interactions. In 70 patients switched to simvastatin, there was no change in mean total cholesterol after four months; one patient reverted to atorvastatin due to adverse effects. Of 115 switched to candesartan, seven reverted to losartan; in the remainder, blood pressure was slightly reduced after four months. The switch was not associated with adverse effects. Savings for the year 2005/06 were estimated at £12 716 for statins and £13 374 for antihypertensive drugs. Scotland gets donepezil for mild to moderate AD The Scottish Medicines Consortium (www.scottish medicines.org.uk) has approved the use of orodispersible donepezil (Aricept Evess) for the treatment of mild to moderate Alzheimer's disease in NHS Scotland. The decision conflicts with NICE advice that the drug is not appropriate for patients with mild disease. The SMC has not approved rimonabant (Acomplia) as adjunctive treatment for obese patients. Adherence threatens anticoagulation Patients find it difficult to adhere to anticoagulant treatment ,significantly impairing the quality of anticoagulation, US investigators have shown (Arch Intern Med 2007;167:229-35). Using electronic containers to monitor dose adherence over 32 weeks in 136 patients, they found that 92 per cent opened the container at least once too often or too little and one-third missed 20 per cent of scheduled openings. Patients with less than 20 per cent adherence were twice as likely to be undercoagulated compared with adherent patients. Those with overadherence were overcoagulated. Hypo risk greatest with glibenclamide Glibenclamide is associated with a significantly greater risk of hypoglycaemic events than other secretagogues, a new systematic review has concluded (Diabetes Care 2007;30:389-94). The review of 21 randomised trials found that the risk of experiencing at least one hypoglycaemic event was 52 per cent greater with glibenclamide compared with other secretagogues and 83 per cent greater than with other sulphonylureas. In three comparative trials with insulin, there was no significant difference in the risk of hypoglycaemia (though this could not be excluded) but only insulin was associated with weight gain. Glibenclamide was not associated with significantly increased risks of cardiovascular events, weight gain or death. Few major hypoglycaemic events were reported in these trials. Drug groups implicated in ADR admissions Four classes of drugs account for half of hospital admissions for adverse reactions, according to a new systematic review (Br J Clin Pharmacol 2007;63:136-47). Antiplatelet agents (16 per cent of admissions), diuretics (16 per cent), NSAIDs (11 per cent) and anticoagulants (8 per cent) were implicated in drug- related admissions according to a review of nine studies. Analysis of five studies also showed that adherence problems were associated with one-third of drug-related admissions. The authors suggest that focussing resources in these areas could substantially reduce admissions. Value of pharmacist MUR questioned Pharmacist medicines use review (MUR) for older patients does not reduce hospital readmission and is not cost effective by current standards, according to a study from Norfolk (Pharmacoeconomics 2007;25:171-80). A total of 872 patients aged over 80 who had been admitted as an emergency and discharged taking two or more drugs were randomised to MUR by a pharmacist or usual care. The pharmacist visited twice, providing education, removing out-of-date drugs and checking for adverse effects, interactions and the need for compliance aids. After six months, the admissions rate was not reduced among patients who received MUR and quality of life was not significantly improved. The estimated cost per QALY gained was £54 454 , above the conventional threshold for cost effectiveness of £30 000. MHRA review of LABAs The MHRA has clarified which aspects of long-acting beta-agonists (LABAs) are being addressed in its current review. This full review of salmeterol (Serevent) and formoterol, following advice issued in December last year, will consider recent research, whether the two agents differ significantly, dose-response relationships, the effect of concurrent treatment with inhaled steroid and how they are used in practice. Manufacturers have been asked to provide data by the end of March. Interventions for weight gain in schizophrenia There is not enough evidence to support the use of drugs to reduce weight gain associated with schizophrenia, a new Cochrane review has found (Cochrane Database of Systematic Reviews 2007, Issue 1. Art. No.: CD005148. DOI: 10.1002/14651858. CD005148.pub2). Noting a lack of adequate trials, the review found that cognitive/behavioural interventions effectively prevented weight gain by a mean of 3.4kg and reduced established weight gain by a mean of 1.7kg. Drugs prevented weight gain by about 1.2kg. Switching anti-TNFs An analysis of a UK rheumatoid arthritis (RA) registry has shown that patients who stop treatment with their first anti-TNF agent should be switched to a second (Arthr Rheum 2007;56:13-20). Every UK patient with RA who receives an anti-TNF agent is included in the British Society for Rheumatology Biologics Register. Analysis of this database identified 6739 patients who started treatment, of whom 841 stopped within 15 months due to lack of efficacy and 1023 due to toxicity. Of these, 503 and 353 respectively were switched to another anti- TNF agent. Overall, 73 per cent of patients remained on their second drug by the end of follow-up, but patients were two to three times more likely to stop their second treatment for the same reason they discontinued their first. Copyright © 2007 Wiley Interface Ltd [source]

Itraconazole vs. fluconazole for antifungal prophylaxis in allogeneic stem-cell transplant patients

CLINICAL MICROBIOLOGY AND INFECTION, Issue 2006
D. J. Winston
Abstract Results from randomised, controlled trials and routine clinical experience indicate that itraconazole can be more effective than fluconazole for prevention of invasive fungal infections in allogeneic stem-cell transplant patients. The effective and safe use of prophylactic itraconazole requires an appreciation of the drug's pharmacokinetics, the optimal dosing regimen, and potential drug interactions. Because of the erratic bioavailability of oral itraconazole capsules, only the intravenous (200 mg once-daily) and oral cyclodextrin solution (200 mg twice-daily) formulations of the drug should be used. Prophylaxis should be started after the completion of pre-transplant chemotherapy in order to avoid interactions with chemotherapeutic agents. Patients unable to tolerate oral itraconazole should be given intravenous itraconazole to maintain effective prophylaxis. Post-transplant interactions between itraconazole and immunosuppressive agents or other drugs are generally not problematic, can be easily managed, and need not limit the use of itraconazole. If these guidelines are followed, Aspergillus and other invasive fungal infections can be safely prevented in allogeneic stem-cell transplant patients. [source]