6.No effect on count, motility, or morphology of sperm.
Pediatrics: Oral doses of 6 to 10 mg/kg/day in two or three divided doses maintain gastric pH>4 throughout most of the dosing interval.
Clinical Trials: Active Duodenal Ulcer: In a multicenter, double-blind, controlled, US study of endoscopically diagnosed duodenal ulcers, earlier healing was seen in the patients treated with Ranitidine Tablets, USP as shown in Table 3
| Table 3. Duodenal Ulcer Patient Healing Rates |
| Ranitidine Tablets, USP * | Placebo* |
Number Entered | Healed / Evaluable | Number Entered | Healed / Evaluable |
Outpatients | 195 | 69/182 (38%) † | 188 | 31-164 (19%) |
| Week 2 |
| Week 4 | 137/187 (73%) † | 76/168 (45%) |
*All patients were permitted antacids as needed for relief of pain.
†P<0.0001.
In these studies, patients treated with Ranitidine Tablets, USP reported a reduction in both daytime and nocturnal pain, and they also consumed less antacid than the placebo-treated patients.
| Table 4. Mean Daily Doses of Antacid |
| Ulcer Healed | Ulcer Not Healed |
| Ranitidine | 0.06 | 0.71 |
| Placebo | 0.71 | 1.43 |
Foreign studies have shown that patients heal equally well with 150 mg twice daily and 300 mg at bedtime (85% versus 84%, respectively) during a usual 4-week course of therapy. If patients require extended therapy of 8 weeks, the healing rate may be higher for 150 mg twice daily as compared to 300 mg at bedtime (92% versus 87%, respectively).
Studies have been limited to short-term treatment of acute duodenal ulcer. Patients whose ulcers healed during therapy had recurrences of ulcers at the usual rates.
Maintenance Therapy in Duodenal Ulcer: Ranitidine has been found to be effective as maintenance therapy for patients following healing of acute duodenal ulcers. In 2 independent, double-blind, multicenter, controlled trials, the number of duodenal ulcers observed was significantly less in patients treated with Ranitidine Tablets, USP (150 mg at bedtime) than in patients treated with placebo over a 12-month period.
| Table 5. Duodenal Ulcer Prevalence |
| Double-Blind, Multicenter, Placebo-Controlled Trials |
Multicenter Trial | Drug | Duodenal Ulcer Prevalence | No. Of Patients |
| | 0 to 4 Months | 0 to 8 Months | 0 to 12 Months | |
| USA | RAN | 20%* | 24%* | 35%* | 138 |
| PLC | 44% | 54% | 59% | 139 |
| Foreign | RAN | 12%* | 21%* | 28%* | 174 |
| PLC | 56% | 64% | 68% | 165 |
% = Life table estimate.
* = P<0.05 (Ranitidine Tablets, USP versus comparator).
RAN = ranitidine (Ranitidine Tablets, USP)
PLC = placebo.
As with other H2-antogonists, the factors responsible for the significant reduction in the prevalence of duodenal ulcers include prevention of recurrence of ulcers, more rapid healing of ulcers that may occur during maintenance therapy, or both.
Gastric Ulcer: In a multicenter, double-blind, controlled, US study of endoscopically diagnosed gastric ulcers, earlier healing was seen in the patients treated with Ranitidine Tablets, USP as shown in Table 6.
| Table 6. Gastric Ulcer Patient Healing Rates |
| Ranitidine Tablets, USP * | Placebo* |
Number Entered | Healed / Evaluable | Number Entered | Healed / Evaluable |
| Outpatients | 92 | 16/83 (19%) † | 94 | 10/83 (12%) |
| Week 2 |
| Week 6 | 50/73 (68%) † | 35/69 (51%) |
*All patients were permitted antacids as needed for relief of pain.
†P = 0.009.
In this multicenter trial, significantly more patients treated with Ranitidine Tablets, USP became pain free during therapy.
Maintenance of Healing of Gastric Ulcers: In two multicenter, double-blind, randomized, placebo-controlled, 12-month trials conducted in patients whose gastric ulcers had been previously healed, Ranitidine Tablets, USP 150 mg at bedtime was significantly more effective than placebo in maintaining healing of gastric ulcers.
Pathological Hypersecretory Conditions (such as Zollinger-Ellison syndrome):
Ranitidine Tablets, USP inhibit gastric acid secretion and reduces occurrence of diarrhea, anorexia, and pain in patients with pathological hypersecretion associated with Zollinger-Ellison syndrome, systemic mastocytosis, and other pathological hypersecretory conditions (e.g., postoperative, "short-gut" syndrome, idiopathic). Use of Ranitidine Tablets, USP was followed by healing of ulcers in 8 of 19 (42%) patients who were intractable to previous therapy.
Gastroesophageal Reflux Disease (GERD): In 2 multicenter, double-blind, placebo-controlled, 6-week trials performed in the United States and Europe, Ranitidine Tablets, USP 150 mg twice daily was more effective than placebo for the relief of heartburn and other symptoms associated with GERD. Ranitidine-treated patients consumed significantly less antacid than did placebo-treated patients.
The US trial indicated that Ranitidine Tablets, USP 150 mg twice daily significantly reduced the frequency of heartburn attacks and severity of heartburn pain within 1 to 2 weeks after starting therapy. The improvement was maintained throughout the 6-week trial period. Moreover, patient response rates demonstrated that the effect on heartburn extends through both the day and night time periods.
In two additional US multicenter, double-blind, placebo-controlled, 2-week trials, Ranitidine Tablets, USP 150 mg twice daily was shown to provide relief of heartburn pain within 24 hours of initiating therapy and a reduction in the frequency of severity of heartburn.
Erosive Esophagitis: In two multicenter, double-blind, randomized, placebo-controlled, 12-week trials performed in the United States, Ranitidine Tablets, USP 150 mg 4 times daily was significantly more effective than placebo in healing endoscopically diagnosed erosive esophagitis and in relieving associated heartburn.
The erosive esophagitis healing rates were as follows:
| Table 7. Erosive Esophagitis Patient Healing Rates |
| Healed / Evaluable |
| Placebo* n=229 | Ranitidine Tablets, USP 150 mg 4 times daily* n=215 |
| Week 4 | 43/198 (22%) | 96/206 (47%) † |
| Week 8 | 63/176 (36%) | 142/200 (71%) † |
| Week 12 | 92/159 (58%) | 162/192 (84%) † |
*All patients were permitted antacids as needed for relief of pain.
†P<0.001 versus placebo.
No additional benefit in healing of esophagitis or in relief of heartburn was seen with a ranitidine dose of 300 mg 4 times daily.
Maintenance of Healing of Erosive Esophagitis: In 2 multicenter, double-blind, randomized, placebo-controlled, 48-week trials conducted in patients whose erosive esophagitis had been previously healed, Ranitidine Tablets, USP 150 mg twice daily was significantly more effective than placebo in maintaining healing of erosive esophagitis.