Kellow et al conducted a study to compare the efficacy of ranitidine and cimetidine in treating chronic gastric ulcers and to observe the adverse effects if any.

Fifty four outpatients who were endoscopically proven to have chronic gastric ulcers were randomly divided into two groups. The first group was treated with ranitidine 150mg twice a day and the other group was treated with cimetidine 200mg 3 times a day and 400mg at night for 4 weeks. After 4 weeks of treatment, patients were again fully assessed. 

9 patients withdrew from the study due to varied reasons and one patient was excluded. Hence, a total of 44 patients were divided into 2 groups consisting of 22 patients each, one group being treated with ranitidine and the other being treated with cimetidine.

 Findings:

• After 4 weeks of treatment, 54% of patients in the ranitidine group and 50% of patients in the cimetidine group showed complete relief from the symptoms.
• Endoscopic healing was observed 59% in the ranitidine group and 64% in the cimetidine group after 4 weeks of treatment. After 8 weeks, 91% of patients in both ranitidine and cimetidine were healed.
• Smoking did not affect the healing rates of both groups.
• No major side effects were observed in either group.

Conclusions:

The study concluded that ranitidine had similar efficacy as cimetidine in healing chronic gastric ulcers and was found to heal 80-90% of ulcers after 8 weeks of treatment.

Source: Kellow JE, Barr GD, Cowen AE, Ward M, Wood L, Piper DW. Comparison of Ranitidine and Cimetidine in the Treatment of Chronic Gastric Ulcer. A double-blind trial. Digestion. 1983;27(2):105-10.