Which was the largest selling drug in the world until ranitidine?

Cimetidine was the largest selling drug in the world until ranitidine was introduced. It belongs to a class of medications known as H2-receptor antagonists, which are used to reduce stomach acid production. This class of drugs was revolutionary in the treatment of conditions like peptic ulcers and gastroesophageal reflux disease (GERD).

Cimetidine's effectiveness, along with its availability in both prescription and over-the-counter forms, contributed significantly to its widespread use and high sales figures. Its success as a treatment option paved the way for subsequent drugs, including ranitidine, which was developed to address similar clinical needs but with improved efficacy and fewer side effects.

In contrast, options such as omeprazole and famotidine, while important medications in their own right, came later or did not achieve the same level of market penetration during that time period. Omeprazole is a proton pump inhibitor that gained popularity later, and famotidine is another H2-receptor antagonist, but cimetidine's historical context and earlier advent put it ahead in sales during its peak. Aluminium hydroxide, also a treatment for stomach acidity and ulcers, functions differently and typically does not achieve the same level of sales figures as H2 antagonists