Varenicline go ahead in heart patients

November 21, 2011 Medicine 110 Comments

In June 2011, the US FDA said that varenicline may increase the risk of adverse cardiovascular events in patients with known cardiovascular disease [1].

This was based on a randomized trial that found a non-statistically significant increase in cardiovascular events in 714 smokers with stable CVD treated with varenicline [2].

Though the rate of cardiovascular mortality was lower and smoking cessation rates were higher in the varenicline group.

A subsequent meta-analysis of 14 randomized placebo-controlled trials of varenicline in 8216 smokers with no or stable CVD found a statistically significant increase in the risk of myocardial ischemia, arrhythmia, heart failure, sudden death, or cardiovascular-related death for the varenicline group [3]. Twenty-eight patients with stable CVD would need to be treated with varenicline for one year to cause one additional serious cardiovascular event while 10 patients would need to be treated for one additional patient to quit smoking.

Over long term benefits of smoking cessation will likely outweigh potential short-term harms of varenicline in CVD patients

References

  1. http://www.fda.gov/Drugs/DrugSafety/ucm259161.htm (Accessed on June 16, 2011).
  2. Rigotti NA, Pipe AL, Benowitz NL, et al. Efficacy and safety of varenicline for smoking cessation in patients with cardiovascular disease: a randomized trial. Circulation 2010;121:221.
  3. Singh S, Loke YK, Spangler JG, Furberg CD. Risk of serious adverse cardiovascular events associated with varenicline: a systematic review and meta-analysis. CMAJ 2011;183:1359.

Do not give citalopram more than 40 mg

September 30, 2011 Health Care, Medicine 177 Comments

Doctors should not give citalopram at doses that exceed 40 mg per day because of dose-dependent QT interval prolongation.

The US FDA issued a safety alert in August 2011 that the antidepressant citalopram should no longer be used at doses exceeding 40 mg per day because higher doses have been associated with an increased risk for potentially fatal cardiac rhythm disturbances, including Torsade de Pointes.

In a randomized trial, the maximum mean corrected QT interval prolongation was greater in patients assigned to receive citalopram 60 mg per day compared with 20 mg per day.

No evidence is available that escitalopram causes dose-dependent QT prolongation. Other SSRIs can also cause QT prolongation, but are safe in usual recommended doses.

[FDA Drug Safety Communication: Abnormal heart rhythms associated with high doses of citalopram hydrobromide. http://www.fda.gov/Drugs/DrugSafety/ucm269086.htm]