A report published in June, 2011 the Journal of the American Geriatrics Society indicate that some drug combinations are linked to increased death risk for elderly.
The relationship between some commonly prescribed medications and the risk of mental deterioration and death in older people were studied at University of East Anglia. The scientists looked at drug combination use in 13,004 people in England and Wales aged 65 or older.
The study was originated from the research on long term health impacts of a side-effect of a number of prescription and over the counter drugs which block a chemical in the brain called acetylcholine in an attempt to to find ways of reducing risk factors for dementia which affects 820,000 people in the UK. 48% of the older people in the study took medication with anticholinergic properties. Each of these medications was ranked according to the strength of the anticholinergic effect (AntiCholinergic Burden) – 0 for no effect, 1 for mild effect, 2 for moderate effect and 3 for severe effect.
The researchers reported that:
- 20% of participants taking medication with a total ACB of four or more had died by the end of the two year study, compared with only seven per cent of those taking no anticholinergic drugs
- For every additional ACB point scored, the odds of dying increased by 26%
- Participants taking drugs with a combined ACB of five or more scored more than four per cent lower in a cognitive function test than those taking no anticholinergic medications
Importantly, they also found that the risk was cumulative, meaning that it increased for patients taking multiple courses of these types of medicines.
The following medications are found to be have worst drug combination problems:
- anti-depressants such as amitriptyline, amipramine and clomipramine
- tranquilisers such as chlorpromazine and trifluoperazine
- bladder medication such as oxybutynin
- antihistamines such as chlorphenamine
Another report in Jan, 2011 by scientist Stony Brook University School of Medicine indicate that Cancer Drug Shows Increased Risk of Death When Used In Combination With Other Drugs or Therapies.
Bevacizumab is FDA-approved for the treatment of metastatic renal cell carcinoma in combination with interferon alfa, as well as colorectal and lung cancer. Shenhong Wu, MD, PhD, and colleagues reviewed 16 published randomized controlled trials on the clinical use of bevacizumab and completed a meta-analysis of adverse effects and mortality rates of 10,217 patients with a variety of advanced solid tumors. The meta-analysis included two phase III trials of renal cell carcinoma and one phase III prostate cancer study.
They discovered the use of bevacizumab in combination with other chemotherapy or biological therapy increased the risk of treatment-related mortality by 46%. The overall incidence of fatal adverse events with bevacizumab was 2.5%. Compared with chemotherapy alone, the addition of bevacizumab was associated with a 1.5 times increased risk of fatal adverse events. This association varied significantly with chemotherapeutic agents but not with tumor types or bevacizumab doses. Bevacizumab was associated with a 3.5 times increased risk of fatal adverse events in patients receiving taxanes or platinum agents (3.3% vs. 1%), but was not associated with increased risk of fatal adverse events when used in conjunction with other agents.
All these results suggests patients and their physicians should review carefully the drug-drug interaction and closely monitor the side effects caused from drug combinations. Patients should reduce the number of medications they use whenever is possible.
