Actions following adverse drug events - how do these influence uptake and utilisation of newer and/or similar medications?

BACKGROUND: Over the last decade, actions following some adverse drug events received major publicity. This study investigated changes in usage patterns of medications in Australia following two examples - rofecoxib market withdrawal (2004) and warnings about jaw necrosis following bisphosphonates (2007). METHODS: Dispensing data for COX-2 inhibitors (2000-2008) and anti-osteoporosis medications (2003-2012) were obtained from the Australian Pharmaceutical Benefits Scheme database. For bisphosphonates, data on Australian marketing expenditures were purchased from Cegedim(R). RESULTS: For COX-2 inhibitors, celecoxib dispensing halved after rofecoxib withdrawal, but meloxicam dispensing increased by 60 %. When lumiracoxib was introduced (2006) there was uptake of prescribing at a faster rate than meloxicam in 2002, its first year of use. For bisphosphonates, alendronate had highest use at the time of the warnings (8.3 DDD/1000/day), dropping to 4.9 DDD/1000/day by 2012. In contrast, risedronate use rose 2007-2012 from 4.1 to 4.9 DDD/1000/day. There was 49 % increase in reported annual expenditure on detailing for risedronate from 2007 to 2008 (to AUD$7.3 million) and only 29 % increase for alendronate (to AUD$3.1 million). CONCLUSIONS: The rapid uptake of prescribing of lumiracoxib and increased use of meloxicam flagged a concern, especially after rofecoxib withdrawal due to safety issues. Bisphosphonates are useful drugs, however the dramatic rise in expenditure on detailing, followed by a rise in utilisation of risedronate could suggest that adverse publicity triggered a marketing response. These examples highlight the importance of tracking utilisation of medication classes in real time, using different data as needed, to ensure that due caution is exercised (and quick intervention provided if needed) for medications in the same class.

Differences in utilisation of gastroprotective drugs between 2001 and 2005 in Australia and Nova Scotia, Canada.

PURPOSE: This study aimed to compare use of histamine H2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs), 2001-2005, in the elderly and social security beneficiaries in Australia (AUS) and Nova Scotia, Canada (NS). METHODS: Prescription dispensing data were collected for all subsidised H2RAs and PPIs. In AUS, dispensing data for concession beneficiaries were obtained from the Pharmaceutical Benefits Scheme database. In NS, data were sourced from the Pharmacare database. Relevant population data were used to convert to World Health Organisation Anatomic Therapeutic Chemical defined daily doses (2005) per 1000 beneficiaries per day (DDD/1000/day). RESULTS: Overall use of gastroprotective agents was similar and rising in NS and AUS (100-160 DDD/1000/day) over this 5-year time window. However, the proportion of this use accounted for by PPIs was far higher in AUS (over 85% by 2005) than in NS (23% rising to 35% over the 5 years). In AUS, PPI use rose from 50 to about 140 DDD/1000/day over the 5 years, whereas PPI use in NS rose slowly to less than 60 DDD/1000/day by 2005. H2RA use in NS was always high (over 100 DDD/1000/day), whereas in AUS, H2RA use fell from 54 to around 24 DDD/1000/day over this period. CONCLUSIONS: AUS had much higher use of PPIs than NS over 2001-2005. The proportion of PPIs in all gastroprotective agents rose in AUS to be nearly 90%. The differences in utilisation during this time window could lead to differences in health outcomes from either lower gastro-intestinal bleeding risk or higher long-term adverse effects of PPIs.

Comparison of nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 (COX-2) inhibitors use in Australia and Nova Scotia (Canada).

AIMS: Cyclooxygenase-2 (COX-2) inhibitors were marketed aggressively and their rapid uptake caused safety concerns and budgetary challenges in Canada and Australia. The objectives of this study were to compare and contrast COX-2 inhibitors and nonselective nonsteroidal anti-inflammatory drug (ns-NSAID) use in Nova Scotia (Canada) and Australia and to identify lessons learned from the two jurisdictions. METHODS: Ns-NSAID and COX-2 inhibitor Australian prescription data (concession beneficiaries) were downloaded from the Medicare Australia website (2001-2006). Similar Pharmacare data were obtained for Nova Scotia (seniors and those receiving Community services). Defined daily doses per 1000 beneficiaries day(-1) were calculated. COX-2 inhibitors/all NSAIDs ratios were calculated for Australia and Nova Scotia. Ns-NSAIDs were divided into low, moderate and high risk for gastrointestinal side-effects and the proportions of use in each group were determined. Which drugs accounted for 90% of use was also calculated. RESULTS: Overall NSAID use was different in Australia and Nova Scotia. However, ns-NSAID use was similar. COX-2 inhibitor dispensing was higher in Australia. The percentage of COX-2 inhibitor prescriptions over the total NSAID use was different in the two countries. High-risk NSAID use was much higher in Australia. Low-risk NSAID prescribing increased in Nova Scotia over time. The low-risk/high-risk ratio was constant throughout over the period in Australia and increased in Nova Scotia. CONCLUSIONS: There are significant differences in Australia and Nova Scotia in use of NSAIDs, mainly due to COX-2 prescribing. Nova Scotia has a higher proportion of low-risk NSAID use. Interventions to provide physicians with information on relative benefits and risks of prescribing specific NSAIDs are needed, including determining their impact.

Gastroprotective drugs in Australia: utilization patterns between 1997 and 2006 in relation to NSAID prescribing.

BACKGROUND: In Australia, the prescribing of proton pump inhibitors (PPIs) and histamine type 2 receptor antagonists (H(2)RAs) for defined gastrointestinal disorders is approved for subsidy by the universal Australian Pharmaceutical Benefits Scheme. These agents also may be used with NSAIDs, but this prescribing is not approved for subsidy. PPI prescribing increased in Australia between 1997 and 2006, and some authorities are concerned that this increase may be due to prescriptions outside the approved indications. OBJECTIVES: The aims of this study were to quantify gastroprotective drug consumption in Australia between 1997 and 2006 and to investigate the relationship over time between this prescribing and NSAID prescribing. METHODS: Data from concession beneficiaries (seniors and welfare recipients) were included. Data on PPIs, H(2)RAs, NSAIDs, and cyclooxygenase (COX)-2 inhibitors dispensed between 1997 and 2006 were gathered from Medicare Australia and are expressed as defined daily doses (DDDs) per 1000 concession beneficiaries per day (CBPDs). Gastroprotective drugs were defined using the World Health Organization Anatomical Therapeutic Chemical classification of 2006. Drug utilization 90% and expenditures in Australian dollars (AUD $, not normalized to an index year) were calculated. RESULTS: H(2)RA prescribing was stable between 1997 and 2001, at approximately 60 DDDs/1000 CBPDs. Dispensation of H(2)RAs began to decrease in 2001 to 20 DDDs/ 1000 CBPDs in 2006. PPI consumption increased consistently, with a sharp change beginning in 2001 (from about 45 to 140 DDDs/1000 CBPDs between 2001 and 2006). The government expenditure for PPIs per concession beneficiary per year also increased from about AUD $26 in 1997 to almost AUD $74 in 2006, whereas the expenditure for H2RAs decreased from about AUD $24 to about AUD $5. Nonselective NSAID prescribing decreased with the introduction of COX-2 inhibitors in 2000. COX-2 inhibitors increased the overall consumption of total NSAIDs in the first 4 years (2000-2003) after their introduction. CONCLUSIONS: The prescribing of H(2)RAs decreased, whereas the prescribing of PPIs increased, between 1997 and 2006 in this population of concession beneficiaries in Australia. During the same period, nonselective NSAID prescribing decreased while COX-2 inhibitor prescribing increased.

Perceived barriers to paracetamol (acetaminophen) prescribing, especially following rofecoxib withdrawal from the market.

Cyclooxygenase-2 inhibitor (COX-2) inhibitors were publicly subsidized in Australia for osteoarthritis. However, guidelines still recommended paracetamol as first choice therapy. When rofecoxib was withdrawn in 2004, paracetamol should have been offered as replacement. However, dispensing data indicate no increase in paracetamol use. The objective of this study was to gain understanding about barriers to paracetamol use and to identify what choices consumers were offered after rofecoxib withdrawal. We conducted two focus groups (consumers and pharmacists) and 15 semi-structured interviews (seven with patients taking rofecoxib at the time it was withdrawn in Australia, four with pharmacists, and four with general practitioners). Familiarity with and use of paracetamol, perceived strengths and weaknesses of paracetamol for chronic pain, and choices given about therapy changes were investigated. All interviews and focus groups were recorded, transcribed verbatim, and thematically analyzed. Consumers reported that transfer of information on their medicines was limited or absent. They perceived that their knowledge about COX-2 inhibitor safety and/or appropriate use of paracetamol was lacking. Pharmacists agreed that several factors were relevant concerning paracetamol and COX-2 inhibitor use, including lack of counseling and information for consumers. Not personalizing prescribing to elderly patients was identified as a weakness. Consumers who had received rofecoxib were divided about their perceptions of the efficacy of paracetamol. It appears that when rofecoxib was withdrawn, they were not offered an opportunity to try paracetamol. Consumers in this study appeared to have poor knowledge about the opportunity to effectively use paracetamol. Consumers did not remember being given the choice to use paracetamol as regular treatment for chronic pain. Pharmacists and doctors did not appear to be discussing options for pain control well with consumers and had mismatched perceptions with consumers about paracetamol. An educational intervention to encourage more rational use of paracetamol is now being planned to provide consumers with more knowledge about paracetamol effective use.

Non-steroidal anti-inflammatory drugs, Cyclooxygenase-2 inhibitors and paracetamol use in Queensland and in the whole of Australia.

BACKGROUND: Cross national drug utilization studies can provide information about different influences on physician prescribing. This is important for medicines with issues around safety and quality of use, like non selective non-steroidal anti-inflammatory drugs (ns-NSAIDs) and cyclo-oxygenase-2 (COX-2) inhibitors. To enable comparison of prescription medicine use across different jurisdictions with a range of population sizes, data first need to be compared within Australia to understand whether use in a smaller sub-population may be considered as representative of the total use within Australia. The aim of this study was to compare the utilization of non selective NSAID, COX-2 inhibitors and paracetamol between Queensland and Australia. METHOD: Dispensing data were obtained for concession beneficiaries for Australia for ns-NSAIDs, COX-2 inhibitors and paracetamol subsidized by the PBS over the period 1997-2003. The same data were purchased for Queensland. Data were converted to Defined Daily Dose (DDD)/1000 beneficiaries/day (World Health Organization anatomical therapeutic chemical classification, 2005). RESULTS: Total NSAID and paracetamol consumption were similar in Australia and Queensland. Ns-NSAID use decreased sharply with the introduction of COX-2 inhibitors (from approximately 80 to 40 DDD/1000 beneficiaries/day). Paracetamol was constant (approximately 45 DDD/1000 beneficiaries/day). COX-2 inhibitors consumption was initially higher in Queensland than in the whole of Australia. CONCLUSION: Despite initial divergence in celecoxib use between Queensland and Australia, the use of ns-NSAIDs, COX-2 inhibitors and paracetamol overall, in concession beneficiaries, was comparable in Australia and Queensland.

Structure-activity relationship of a series of synthetic lipopeptide self-adjuvanting group a streptococcal vaccine candidates.

The development of 16 self-adjuvanting group A streptococcal vaccine candidates, composed of (i) a universal helper T-cell epitope (P25), (ii) a target GAS B-cell epitope (J14), and (iii) a lipid moiety, is described. Systemic J14-specific IgG antibodies were detected following subcutaneous immunization of BALB/c (H-2 (d)) mice with each construct without the need for an additional adjuvant. The effect of changing the order of P25, J14, and lipid moiety attachment or incorporation of P25 and J14 into a lipid-core peptide system on antibody titers was assessed. The point of lipid moiety attachment had the greatest influence on systemic J14-specific IgG antibody titers. Overall, the best vaccines featured a C-terminal lipid moiety, conjugated through a lysine residue to P25 at the N-terminus, and J14 on the lysine side chain.

What happened to the prescribing of other COX-2 inhibitors, paracetamol and non-steroidal anti-inflammatory drugs when rofecoxib was withdrawn in Australia?

OBJECTIVES: To analyse how the prescribing of cyclooxygenase-2 (COX-2) inhibitors, non-selective non-steroidal anti-inflammatory drugs (ns-NSAIDs) and paracetamol (acetaminophen) changed when rofecoxib was withdrawn in 2004. METHOD: COX-2 inhibitors, paracetamol and ns-NSAID's use was measured using dispensing data for concession beneficiaries subsidized by the Australian Pharmaceutical Benefit Scheme (PBS) for the period of 1997-2005. Data were downloaded from the Medicare Australia website and converted, according to the World Health Organization (WHO) Anatomical Therapeutic Chemical (ATC)/Defined Daily Dose (DDD) (2005), to DDD/1000 concession beneficiaries/day. RESULTS: In the period 2000-2004, the use of COX-2 inhibitors was progressively increased. Overall NSAID's use changed from approximately 80 to 105 DDD/1000 concession beneficiaries/day while a decrease of ns-NSAIDs from about 70 to 40 DDD/1000 concession beneficiaries/day was observed. Following rofecoxib withdrawal, the overall NSAIDs use declined. In 2005, celecoxib prescription declined (23%) while prescription of meloxicam increased by 62%. Use of paracetamol was steady over the period 1997-2004 (around 40 DDD/1000 concession beneficiaries/day). In April 2005, a slight increase in paracetamol use was observed. CONCLUSION: Our analysis showed that COX-2 inhibitors prescribing markedly influenced the overall NSAIDs prescribing in Australia. When COX-2 inhibitors were introduced their uptake was rapid and extensive. Following rofecoxib withdrawal, the total overall dispensing of NSAIDs returned to a similar value as before COX-2 inhibitors' introduction. The decrease was due both to rofecoxib withdrawal and to a reduction in celecoxib prescribing. However, meloxicam use increased. Paracetamol prescribing was steady, between 1997 and 2005 and was not affected when the COX-2 inhibitors were introduced on to the market and after rofecoxib withdrawal, rather than increasing as might have been anticipated after rofecoxib withdrawal.

Immunization with a tetraepitopic lipid core peptide vaccine construct induces broadly protective immune responses against group A streptococcus.

BACKGROUND: The development of a vaccine to prevent infection with group A streptococcus (GAS) is hampered by the widespread diversity of circulating GAS strains and M protein types, and it is widely believed that a multivalent vaccine would provide better protective immunity. METHODS: We investigated the efficacy of incorporating 3 M protein serotypic amino-terminal epitopes from GAS isolates that are common in Australian Aboriginal communities and a conformational epitope from the conserved carboxy-terminal C-repeat region into a single synthetic lipid core peptide (LCP) vaccine construct in inducing broadly protective immune responses against GAS after parenteral delivery to mice. RESULTS: Immunization with the tetraepitopic LCP vaccine construct led to high titers of systemic, antigen-specific IgG responses and the induction of broadly protective immune responses, as was demonstrated by the ability of immune serum to opsonize multiple GAS strains. Systemic challenge of mice with a lethal dose of GAS given 60 or 300 days after primary immunization showed that, compared with the control mice, the vaccinated mice were significantly protected against GAS infection, demonstrating that the vaccination stimulated long-lasting protective immunity. CONCLUSIONS: These data support the efficacy of the LCP vaccine delivery system in the development of a synthetic, multiepitopic vaccine for the prevention of GAS infection.

Specific modulation of airway epithelial tight junctions by apical application of an occludin peptide.

Tight junctions are directly involved in regulating the passage of ions and macromolecules (gate functions) in epithelial and endothelial cells. The modulation of these gate functions to transiently regulate the paracellular permeability of large solutes and ions could increase the delivery of pharmacological agents or gene transfer vectors. To reduce the inflammatory responses caused by tight junction-regulating agents, alternative strategies directly targeting specific tight junction proteins could prove to be less toxic to airway epithelia. The apical delivery of peptides corresponding to the first extracellular loop of occludin to transiently modulate apical paracellular flux has been demonstrated in intestinal epithelia. We hypothesized that apical application of these occludin peptides could similarly modulate tight junction permeability in airway epithelia. Thus, we investigated the effects of apically applied occludin peptide on the paracellular permeability of molecular tracers and viral vectors in well differentiated human airway epithelial cells. The effects of occludin peptide on cellular toxicity, tight junction protein expression and localization, and membrane integrity were also assessed. Our data showed that apically applied occludin peptide significantly reduced transepithelial resistance in airway epithelia and altered tight junction permeability in a concentration-dependent manner. These alterations enhanced the paracellular flux of dextrans as well as gene transfer vectors. The occludin peptide redistributed occludin but did not alter the expression or distribution of ZO-1, claudin-1, or claudin-4. These data suggest that specific targeting of occludin could be a better-suited alternative strategy for tight junction modulation in airway epithelial cells compared with current agents that modulate tight junctions.