Look twice at the med list before you prescribe these!

Two distinguished guests join me this month, David Juurlink (@DavidJuurlink) and Bryan Hayes (@PharmERToxyGuy), to discuss medication interactions. There are many medications that we commonly prescribe in the ED that can have potentially deadly side effects when combined with other medications that a patient is already on. It is important to always check the patient’s medication list prior to writing a new script. We present two examples of clinical cases in which commonly used medications could prove dangerous in combination with other medications: cellulitis and a community-acquired pneumonia. We discuss potential side effects from medication interactions (with a little pathophysiology thrown in), and some alternative medications that may be safer.

References:

1. Baillargeon J, Holmes HM, Lin YL, Raji MA, Sharma G, Kuo YF. Concurrent use of warfarin and antibiotics and the risk of bleeding in older adults. Am J Med. 2012;125(2):183-189. http://www.ncbi.nlm.nih.gov/pubmed/22269622
2. Ho JM, Juurlink DN. Considerations when prescribing trimethoprim-sulfamethoxazole. CMAJ. 2011;183(16):1851-1858. http://www.ncbi.nlm.nih.gov/pubmed/21989472
3. Fralick M, Macdonald EM, Gomes T, et al. Co-trimoxazole and sudden death in patients receiving inhibitors of renin-angiotensin system: Population based study. BMJ. 2014;349:g6196. http://www.ncbi.nlm.nih.gov/pubmed/25359996
4. Juurlink DN, Mamdani M, Kopp A, Laupacis A, Redelmeier DA. Drug-drug interactions among elderly patients hospitalized for drug toxicity. JAMA. 2003;289(13):1652-1658. http://www.ncbi.nlm.nih.gov/pubmed/12672733
5. Juurlink DN. The cardiovascular safety of azithromycin. CMAJ. 2014;186(15):1127-1128. http://www.ncbi.nlm.nih.gov/pubmed/25096666
6. Wright AJ, Gomes T, Mamdani MM, Horn JR, Juurlink DN. The risk of hypotension following co-prescription of macrolide antibiotics and calcium-channel blockers. CMAJ. 2011;183(3):303-307. http://www.ncbi.nlm.nih.gov/pubmed/21242274

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