{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/27517"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/27517","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"The pharmacokinetics of ranitidine in patients with chronic duodenal ulceration and in patients with chronic renal failure","abstract":"The pharmacokinetics of orally administered ranitidine were studied in 10 patients with endoscopically proved duodenal ulceration after a single 150 mg dose and after 4 weeks 1 ranitidine treatment (150 mg twice daily), at which time there was endoscopic evidence of complete ulcer healing. After a single dose the median elimination half-life was 135 minutes and the median area under the curve (AUC) was l 844 ng/ml.hr. Although the maximum concentration after a single dose (Cmax = 365 ng/ml) was significantly different from that after continuous treatment (Cmax = 562 ng/ml) (p <0,05) there was no significant difference between the minimum concentrations at 12 hours post-dosing (Cmin = 35 ng/ml and 30 ng/ml respectively) and the median half-lives were identical. No accumulation of ranitidine occurred in these patients after 4 weeks' chronic ranitidine treatment. Five patients received 20 mg ranitidine intravenously. The apparent volume of distribution of the central compartment ranged from 10,5 to 28,4 1 while the elimination rate constant β range from 0,34 to 0,78 h⁻¹ with the t½ ranging from 53 to 122 minutes. The mean oral bioavailability was 51%. The pharmacokinetics of ranitidine were studied in a further 7 patients with chronic duodenal ulceration who showed endoscopic evidence of unhealed ulcers after at least 8 weeks' treatment with ranitidine. There were no significant differences in any of the pharmacokinetic parameters when these patients were compared with the 10 responders above after multiple-dosage except that the disposition rate constant was smaller in non-responders (0,24 h⁻¹ compared with 0,31 h⁻¹, p <0,002). Two patients did, however, have very low plasma concentrations with above average basal and maximal acid output which may have contributed to the lack of response to ranitidine treatment. Single- and multiple-dose pharmacokinetic studies of oral ranitidine were carried out in 6 patients with chronic renal failure (RF) (creatinine clearance <25 ml/min) and compared with those obtained for the 10 patients with chronic duodenal ulceration with normal renal function (creatinine clearance >65 ml/min). There appeared to be no significant differences in absorption rate or amount absorbed but the median elimination rate constant was significantly reduced from 0,31 h⁻¹ in controls to 0,14 h⁻¹ in RF (p <0,002) resulting in a two-fold increase in t½ (312 minutes) after a single dose. Cmax did not differ significantly although Cmin and AUC were significantly larger in RF patients (both p <0,002). It is suggested that the dosage of ranitidine be reduced from 150 mg to 75 mg twice daily in severe renal failure although it was not possible to relate half-life, elimination rate constant or AUC directly to creatinine clearance.","abstract_html":"The pharmacokinetics of orally administered ranitidine were studied in 10 patients with endoscopically proved duodenal ulceration after a single 150 mg dose and after 4 weeks 1 ranitidine treatment (150 mg twice daily), at which time there was endoscopic evidence of complete ulcer healing. After a single dose the median elimination half-life was 135 minutes and the median area under the curve (AUC) was l 844 ng/ml.hr. Although the maximum concentration after a single dose (Cmax = 365 ng/ml) was significantly different from that after continuous treatment (Cmax = 562 ng/ml) (p &lt;0,05) there was no significant difference between the minimum concentrations at 12 hours post-dosing (Cmin = 35 ng/ml and 30 ng/ml respectively) and the median half-lives were identical. No accumulation of ranitidine occurred in these patients after 4 weeks&#x27; chronic ranitidine treatment. Five patients received 20 mg ranitidine intravenously. The apparent volume of distribution of the central compartment ranged from 10,5 to 28,4 1 while the elimination rate constant β range from 0,34 to 0,78 h⁻¹ with the t½ ranging from 53 to 122 minutes. The mean oral bioavailability was 51%. The pharmacokinetics of ranitidine were studied in a further 7 patients with chronic duodenal ulceration who showed endoscopic evidence of unhealed ulcers after at least 8 weeks&#x27; treatment with ranitidine. There were no significant differences in any of the pharmacokinetic parameters when these patients were compared with the 10 responders above after multiple-dosage except that the disposition rate constant was smaller in non-responders (0,24 h⁻¹ compared with 0,31 h⁻¹, p &lt;0,002). Two patients did, however, have very low plasma concentrations with above average basal and maximal acid output which may have contributed to the lack of response to ranitidine treatment. Single- and multiple-dose pharmacokinetic studies of oral ranitidine were carried out in 6 patients with chronic renal failure (RF) (creatinine clearance &lt;25 ml/min) and compared with those obtained for the 10 patients with chronic duodenal ulceration with normal renal function (creatinine clearance &gt;65 ml/min). There appeared to be no significant differences in absorption rate or amount absorbed but the median elimination rate constant was significantly reduced from 0,31 h⁻¹ in controls to 0,14 h⁻¹ in RF (p &lt;0,002) resulting in a two-fold increase in t½ (312 minutes) after a single dose. Cmax did not differ significantly although Cmin and AUC were significantly larger in RF patients (both p &lt;0,002). It is suggested that the dosage of ranitidine be reduced from 150 mg to 75 mg twice daily in severe renal failure although it was not possible to relate half-life, elimination rate constant or AUC directly to creatinine clearance.","abstract_has_math":false,"creators":["McFadyen, Margaret Lynn"],"institution":"Division of Clinical Pharmacology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Folb, Peter I"],"committee_chairs":[],"committee_members":[],"year":1981,"date_issued":"1981","date_published":"1981","updated_at":"2026-07-22T22:23:30Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/27517","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Folb, Peter I"]},{"key":"dc:creator","label":"Author","values":["McFadyen, Margaret Lynn"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2018-02-12T08:47:04Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2018-02-12T08:47:04Z"]},{"key":"dc:date.issued","label":"Date","values":["1981"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Division of Clinical Pharmacology"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc (Med)"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/27517"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The pharmacokinetics of orally administered ranitidine were studied in 10 patients with endoscopically proved duodenal ulceration after a single 150 mg dose and after 4 weeks 1 ranitidine treatment (150 mg twice daily), at which time there was endoscopic evidence of complete ulcer healing. After a single dose the median elimination half-life was 135 minutes and the median area under the curve (AUC) was l 844 ng/ml.hr. Although the maximum concentration after a single dose (Cmax = 365 ng/ml) was significantly different from that after continuous treatment (Cmax = 562 ng/ml) (p <0,05) there was no significant difference between the minimum concentrations at 12 hours post-dosing (Cmin = 35 ng/ml and 30 ng/ml respectively) and the median half-lives were identical. No accumulation of ranitidine occurred in these patients after 4 weeks' chronic ranitidine treatment. Five patients received 20 mg ranitidine intravenously. The apparent volume of distribution of the central compartment ranged from 10,5 to 28,4 1 while the elimination rate constant β range from 0,34 to 0,78 h⁻¹ with the t½ ranging from 53 to 122 minutes. The mean oral bioavailability was 51%. The pharmacokinetics of ranitidine were studied in a further 7 patients with chronic duodenal ulceration who showed endoscopic evidence of unhealed ulcers after at least 8 weeks' treatment with ranitidine. There were no significant differences in any of the pharmacokinetic parameters when these patients were compared with the 10 responders above after multiple-dosage except that the disposition rate constant was smaller in non-responders (0,24 h⁻¹ compared with 0,31 h⁻¹, p <0,002). Two patients did, however, have very low plasma concentrations with above average basal and maximal acid output which may have contributed to the lack of response to ranitidine treatment. Single- and multiple-dose pharmacokinetic studies of oral ranitidine were carried out in 6 patients with chronic renal failure (RF) (creatinine clearance <25 ml/min) and compared with those obtained for the 10 patients with chronic duodenal ulceration with normal renal function (creatinine clearance >65 ml/min). There appeared to be no significant differences in absorption rate or amount absorbed but the median elimination rate constant was significantly reduced from 0,31 h⁻¹ in controls to 0,14 h⁻¹ in RF (p <0,002) resulting in a two-fold increase in t½ (312 minutes) after a single dose. Cmax did not differ significantly although Cmin and AUC were significantly larger in RF patients (both p <0,002). It is suggested that the dosage of ranitidine be reduced from 150 mg to 75 mg twice daily in severe renal failure although it was not possible to relate half-life, elimination rate constant or AUC directly to creatinine clearance."]},{"key":"dc:title","label":"Title","values":["The pharmacokinetics of ranitidine in patients with chronic duodenal ulceration and in patients with chronic renal failure"]}]}],"canonical_facts":{"dc:contributor.advisor":["Folb, Peter I"],"dc:creator":["McFadyen, Margaret Lynn"],"dc:date.accessioned":["2018-02-12T08:47:04Z"],"dc:date.available":["2018-02-12T08:47:04Z"],"dc:date.issued":["1981"],"dc:description.abstract":["The pharmacokinetics of orally administered ranitidine were studied in 10 patients with endoscopically proved duodenal ulceration after a single 150 mg dose and after 4 weeks 1 ranitidine treatment (150 mg twice daily), at which time there was endoscopic evidence of complete ulcer healing. After a single dose the median elimination half-life was 135 minutes and the median area under the curve (AUC) was l 844 ng/ml.hr. Although the maximum concentration after a single dose (Cmax = 365 ng/ml) was significantly different from that after continuous treatment (Cmax = 562 ng/ml) (p <0,05) there was no significant difference between the minimum concentrations at 12 hours post-dosing (Cmin = 35 ng/ml and 30 ng/ml respectively) and the median half-lives were identical. No accumulation of ranitidine occurred in these patients after 4 weeks' chronic ranitidine treatment. Five patients received 20 mg ranitidine intravenously. The apparent volume of distribution of the central compartment ranged from 10,5 to 28,4 1 while the elimination rate constant β range from 0,34 to 0,78 h⁻¹ with the t½ ranging from 53 to 122 minutes. The mean oral bioavailability was 51%. The pharmacokinetics of ranitidine were studied in a further 7 patients with chronic duodenal ulceration who showed endoscopic evidence of unhealed ulcers after at least 8 weeks' treatment with ranitidine. There were no significant differences in any of the pharmacokinetic parameters when these patients were compared with the 10 responders above after multiple-dosage except that the disposition rate constant was smaller in non-responders (0,24 h⁻¹ compared with 0,31 h⁻¹, p <0,002). Two patients did, however, have very low plasma concentrations with above average basal and maximal acid output which may have contributed to the lack of response to ranitidine treatment. Single- and multiple-dose pharmacokinetic studies of oral ranitidine were carried out in 6 patients with chronic renal failure (RF) (creatinine clearance <25 ml/min) and compared with those obtained for the 10 patients with chronic duodenal ulceration with normal renal function (creatinine clearance >65 ml/min). There appeared to be no significant differences in absorption rate or amount absorbed but the median elimination rate constant was significantly reduced from 0,31 h⁻¹ in controls to 0,14 h⁻¹ in RF (p <0,002) resulting in a two-fold increase in t½ (312 minutes) after a single dose. Cmax did not differ significantly although Cmin and AUC were significantly larger in RF patients (both p <0,002). It is suggested that the dosage of ranitidine be reduced from 150 mg to 75 mg twice daily in severe renal failure although it was not possible to relate half-life, elimination rate constant or AUC directly to creatinine clearance."],"dc:identifier.uri":["http://hdl.handle.net/11427/27517"],"dc:language.iso":["eng"],"dc:publisher.department":["Division of Clinical Pharmacology"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["The pharmacokinetics of ranitidine in patients with chronic duodenal ulceration and in patients with chronic renal failure"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc (Med)"]},"updated_at":"2026-07-22T22:23:30Z"}