Legend
Reactions in bold italic are life-threatening
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OTC
*Liquid contains alcohol
Photo Guide
Do not crush
Off-label use
Interactions may have a:
rapid onset
delayed onset
The Black Box Warning logo indicates FDA-issued black box warnings.
Rating System for the Hierarchy of Evidence for Intervention/Treatment Questions

The following leveling system is from Evidence-Based Practice in Nursing and Healthcare: A Guide to Best Practice (2nd ed.) by Bernadette Mazurek Melnyk and Ellen Fineout-Overholt.

Level I:Evidence from a systematic review or meta-analysis of all relevant randomized controlled trials (RCTs)
Level II:Evidence obtained from well-designed RCTs
Level III:Evidence obtained from well-designed controlled trials without randomization
Level IV:Evidence from well-designed case-control and cohort studies
Level V:Evidence from systematic reviews of descriptive and qualitative studies
Level VI:Evidence from single descriptive or qualitative studies
Level VII:Evidence from the opinion of authorities and/or reports of expert committees

Modified from Guyatt, G. & Rennie, D. (2002). Users' Guides to the Medical Literature. Chicago, IL: American Medical Association; Harris, R.P., Hefland, M., Woolf, S.H., Lohr, K.N., Mulrow, C.D., Teutsch, S.M., et al. (2001). Current Methods of the U.S. Preventive Services Task Force: A Review of the Process. American Journal of Preventive Medicine, 20, 21-35.