Drug Safety Informations Updated

Drug Safety Communications posted by FDA from September 1, 2008 to November 30, 2008 review the drug safety:

• Phenytoin

New data suggest a potential increased risk of phenytoin or fosphenytoin-induced serious skin reactions (Stevens-Johnson syndrome and toxic epidermal necrolysis) in patients with the human leukocyte antigen allele, HLA-B*1502.

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• Bisphosphonates

Update to FDA’s review of safety data regarding the potential increased risk of atrial fibrillation in patients treated with a bisphosphonate drug. One large study of zoledronic acid showed a statistically significant increase in the rate of serious atrial fibrillation events. However, across all studies involving 19,687 patients treated with bisphosphonates, no clear association between bisphosphonate use and serious or non-serious atrial fibrillation was observed.

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• Tiotropium bromide

Ongoing safety review to evaluate increased risk of stroke in patients taking tiotropium bromide. Preliminary findings from the UPLIFT trial showed that there was no increased risk of stroke with the drug in comparison to placebo.

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Proton pump inhibitors and Possible fracture risk

Proton pump inhibitors and Possible fracture risk

Example of Proton Pump Inhibitor:

· Omeprazole (Losec)

· Esomeprazole (Nexium)

· Pantoprazole (Controloc)

A Canadian review of administrative data (electronic bills submitted by medical professionals) spanning 1996-2004 showed an increased risk of hip fractures for people exposed to PPIs for 5 years or more. After 7 or more years of exposure to PPIs the risk of hip fractures increased even further (OR = 4.55, 95% CI 1.68-12.29, p = 0.002).

A review of data from the year 2000 in the Danish National Hospital Discharge Registry (where clinicians code admission diagnosis according to ICD criteria) showed that exposure to PPIs within the preceding year was associated with an increased overall fracture risk and an even greater risk of hip fracture (OR 1.45, 95% CI 1.28-1.65)

These studies are observational in design and consequently are subject to confounding. Further study is necessary to verify and more clearly define the association.

The biological mechanism underlying this possible association is unknown. One explanation may be that the absorption of dietary calcium is dependent on a low pH in the stomach and as PPIs are potent inhibitors of acid secretion from the gastric parietal cells, there will be an increase in pH. However the effect of this, if any, on bone density in the long term is still unknown and it is certainly possible that other factors contribute to the observed increase in fracture risk.

ADRAC also reminds prescribers to be aware of the potential cumulative risk for individuals taking more than one medication known to increase fracture risk. This risk should also be taken into account when prescribing concomitant medicines known to increase the risk of falls.

Picked from (Australian Adverse Drug Reactions Bulletin Volume 28, Number 1, February 2009, )