You are checking a glaucoma patient's drop bottles at the front desk. One bottle is Trusopt, a topical carbonic anhydrase inhibitor. You want to confirm the class from the standard cap color code. What color cap does Trusopt have?
Trusopt carries an orange cap. Trusopt is the brand name for dorzolamide. Dorzolamide is a topical carbonic anhydrase inhibitor, often shortened to CAI. Orange is the cap color used for this class of eye drop. The color code lets you sort a patient's bottles by class in a few seconds, even before you read the labels. Every top in a glaucoma patient's bag can be matched to a class this way.
CAIs lower pressure by slowing the making of aqueous humor. Aqueous humor is the clear fluid the eye produces inside the front of the globe. The eye makes aqueous humor all day and drains it all day. A CAI works on the making side of that balance. Less fluid made means less pressure built up. The two topical CAIs are dorzolamide (Trusopt) and brinzolamide (Azopt). The oral forms are acetazolamide (Diamox) and methazolamide (Neptazane). Oral CAIs cause more body-wide side effects. These include tingling in the hands and feet, loss of appetite, a metallic taste, and kidney stones. Dorzolamide is also sold together with timolol, under the brand name Cosopt.
Learn the cap colors as a safety habit. They help you catch a refill error or a mixed-up bottle before a patient uses it. They also help you ask better history questions about each class. Read the label as well, since a color can be misread in poor light. Ask which bottle goes in which eye and how often, then chart the answers. Knowing drug classes, brand names, and cap colors is a core part of the COA pharmacology content area.
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