Therapeutics Letter

Glucose lowering drugs are commonly prescribed in British Columbia, and 44% of adults with type 2 diabetes are receiving more than one drug (see Table). Annual spending on non-insulin glucose lowering drugs in Canada was $748 million in 2013.1 When these drugs are taken, the underlying unproven assumption is that by lowering glucose they will prevent the complications of diabetes: premature … [Read more...]

Anemia affects about one-third of humans; iron (Fe) deficiency is the most common cause.1 In Canada (2009-11), deficiency defined as serum ferritin < 15 mcg/L was estimated to affect 13% of females aged 12-19, and 9% of females aged 20-49.2 This estimate is probably low, as the ferritin cutoff is arbitrary and it excludes residents of First Nation reserves, where nutrition is often inferior to … [Read more...]

Chronic pain (at times presumed to be “neuropathic” in origin) is a common problem in clinical practice. It is now well recognized that the results of drug treatment are more often disappointing than not.1 Despite this, from 2005-2014 the number of British Columbians prescribed gabapentin increased 1.8 fold, pregabalin 17 fold, and duloxetine 3.6 fold (from 2008). Use of venlafaxine (mostly for … [Read more...]

This Letter reviews clinical evidence for use of antipsychotics for depression. In Canada, two antipsychotic drugs are approved to treat major depressive disorder (MDD) that is not responsive to other treatment. Quetiapine (Seroquel XR) is approved as monotherapy or in combination with conventional antidepressants for symptomatic relief of MDD “when currently available approved antidepressant … [Read more...]

The antiplatelet drugs acetylsalicylic acid (ASA), clopidogrel (Plavix) and ticlopidine (Ticlid) were reviewed in TL #37.1 Ticlopidine is no longer available in Canada. ASA has a unique action, irreversibly inhibiting platelet cyclooxygenase. Clopidogrel and two new drugs, prasugrel (Effient) and ticagrelor (Brilinta), reduce platelet activation and aggregation by inhibiting P2Y12 adenosine … [Read more...]

Two previous Therapeutics Letters on drugs for overactive bladder (OAB) concluded that the antimuscarinic drugs (oxybutynin, tolterodine, darifenacin, solifenacin and trospium) had limited short-term potential symptomatic benefit (NNT = 7) and significant risk of adverse effects (NNH = 5).1, 2 This Letter compares drugs to one another, including newer drugs introduced since 2007, when our most … [Read more...]

Clinicians are often advised to use surrogate markers to help guide drug therapy. This typically occurs with guideline-based therapy for chronic conditions, such as type II diabetes mellitus1 and cardiovascular disease.2 The US Food and Drug Administration defines a surrogate as “a laboratory measurement or physical sign that is used in therapeutic trials as a substitute for a clinically … [Read more...]