"Oh by the way, I just started taking....."

The case today in morning report had multiple issues, but one that I wanted to discuss more was that of drug reactions. 

This patient was recently treated for a presumed UTI, and is now presenting with an acute elevation in her liver enzymes and a rash.

See this previous post in regards to the approach to transaminitis

This patient's history revealed that she was seen a week prior in the ER, diagnosed as having a UTI and treated with nitrofurantoin. In retrospect, 2 days after starting this medication she developed a rash over her chest, and ultimately was found to have a rise in her liver enzymes that subsequently started to improve once her medications were held. 

To complicate matters the patient was also taking PRN ibuprofen, as well as regular standing medications of tramadol, ASA, clopidogrel, a statin, and ezetimibe. 

Always consider the medications... whether prescribed, OTC, other sources. Careful history with precise timing is key to understanding IF a drug is the cause, and if so, which one. When considering a drug reaction, it is useful to carefully plot out the course of meds and the onset of symptoms/signs.

Remember that a simple exanthem is differentiated by a complex exanthem based on whether or not there is systemic organ involvement. Fever and elevation in liver enzymes are classic associated elements. (Impossible to know if fever played a role due to her antipyretic use).

Often, with multiple medications, it may be difficult to know exactly which is implicated, and often we simply don't know. If medications are ever reintroduced, remember (if possible) to do so one at a time to monitor for a reaction.

This case continues to be one in progress, but time will tell if this is all related to a drug reaction, or if other processes are at play.

See this nice review article from the perspective of a clinical pharmacist on drug induced rashes.

Also, a drug we do not often use...tramadol. See this CMAJ 5 things to know about tramadol article.