Abstract
The plasma concentration-time curve and urinary excretion of cimetidine were followed in 10 patients after single 200mg doses given intravenously, in 9 patients after 400 and 800mg single oral doses, and in 10 patients over a 24-hour period during continuous oral treatment with 1000mg daily.
The bioavailability of cimetidine measured as the ratio between the areas under the plasma concentration-time curves (AUC) after oral and intravenous administration was 76%. The mean excretion of cimetidine in the urine as unchanged drug, expressed as a percentage of administered dose, was 58% after 200mg intravenously and between 37 and 41% after single oral doses of 200, 400 and 800mg and during continuous treatment with 1.0g/day. Since there were no significant differences between the oral doses, the relative bioavailability of cimetidine does not appear to be dose-dependent.
The AUC after the 800mg dose was 2.1 times that of the 400mg dose. No dose-dependent kinetics were observed. There were also no significant differences in the AUCs after 200 and 400mg doses during continuous treatment compared with the AUCs after the same single doses. Thus, cimetidine does not appear to induce or inhibit its own metabolism during treatment.
Following intravenous administration, the mean volume of distribution was 1.39L/kg and the mean total body clearance and the mean plasma renal clearance of cimetidine were 655 and 375ml/min, respectively. A renal clearance of cimetidine more than 3 limes higher than the creatinine clearance demonstrates that the renal excretion of cimetidine is mainly by tubular secretion.
Plasma concentrations of cimetidine during continuous treatment with 1.0g/day were above 1.0μg/ml — the plasma concentration associated with 50% inhibition of stimulated acid secretion in peptic ulcer patients — for 9 out of the 24 hours. A morning plasma concentration above 0.6μg/ml before the next morning dose has been taken during treatment with cimetidine 1.0g/day is only seen in patients with some degree of renal failure.
Measurement of plasma half-life during continuous treatment shows that the plasma half-life is longer than the mean 1.79 hours estimated after intravenous administration of a single dose.
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Bodemar, G. and Walan, A.: Maintenance treatment of recurrent peptic ulcer by cimetidine. Lancet 1: 404–407 (1978).
Bodemar, G.; Mills, J.G.; Norlander, B.; Osborne, P.; Burland, W.L. and Walan, A.: Effects of antacids on the absorption of cimetidine. Gut 19; 990–991A (1978).
Bodemar, G.; Norlander, B.; Fransson, L. and Walan, A.: The absorption of cimetidine before and during maintenance treatment with cimetidine and the influence of a meal on the absorption of cimetidine in patients with peptic ulcer disease. British Journal of Clinical Pharmacology 7: 23–31 (1979a).
Bodemar, G.; Norlander, B. and Walan, A.; Diminished absorption of cimetidine caused by antacids. Lancet 1: 444–445 (1979b).
Burland, W.L.; Duncan, W.A.N.; Hesselbo, T.; Mills, J.G.; Sharpe, P.C.; Haggie, S.J. and Wyllie, J.H.: Pharmacological evaluation of cimetidine, a new histamine H2-receptor antagonist, in healthy man. British Journal of Clinical Pharmacology 2; 481–486 (1975).
Griffiths, R.; Lee, R.M. and Taylor, D.C.: Kinetics of cimetidine in man and experimental animals; in Burland and Simkins (Eds) Cimetidine pp.38–51 (Excerpta Medica, Amsterdam, Oxford 1977).
Gugler, R. and Somogyi, A.: Reduced cimetidine clearance with age. New England Journal of Medicine 301: 439 (1979).
Larsson, R.; Bodemar, G. and Norlander, B.: Oral absorption of cimetidine and its clearance in patients with renal failure. Europ. J. Clin. Pharmacol. 15: 153–157 (1979a).
Larsson, R.; Bodemar, G. and Kågedal, B.: The effect of cimetidine, a new histamine H2-receptor antagonist, on renal function. Acta Medica Scandinavica 205: 87–89 (1979b).
Larsson, R.; Norlander, B.; Bodemar, G. and Walan, A.: Steady-state kinetics and dosage requirements of cimetidine in renal failure. Clinical Pharmacokinetics 6: 316–325 (1981a).
Larsson, R.; Bodemar, G.; Walan, A. and Kågedal, B.: The effects of cimetidine (Tagamet®) on renal function in patients with renal failure. Acta Medica Scandinavica 208: 27–31 (1980).
Ma, K.W.; Brown, D.C.; Master, D.S. and Silvis, S.E.: Effects of renal failure on blood levels of cimetidine. Gastroenterology 74: 473–477 (1978).
Pounder, R.E.; Williams, J.G.; Hunt, R.H.; Vincent, S.H.; Milton-Thompson, G.J. and Misiewics, J.J.: The effects of oral cimetidine on food-stimulated gastric acid secretion and 24-hr intragastric acidity; in Burland and Simkins (Eds) Cimetidine, pp.189–204 (Excerpta Medica, Amsterdam 1977).
Rune, S.J.; Hesselfeldt, P. and Larsen, N.E.: Clinical and pharmacological effectiveness of cimetidine in duodenal ulcer patients. Scand. J. Gastroenterol. 14: 489–492 (1979).
Somogyi, A.; Rohner, H.G. and Gugler, R.: Pharmacokinetics and bioavailability of cimetidine in gastric and duodenal ulcer patients. Clinical Pharmacokinetics 5: 84–94 (1980).
Walkenstein, S.S.; Dubb, J.W.; Randolph, W.C.; Westlake, W.J.; Stote, R.M. and Intoccia, A.P.: Bioavailability of cimetidine in man. Gastroenterology 74: 360–365 (1978).
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Bodemar, G., Norlander, B. & Walan, A. Pharmacokinetics of Cimetidine after Single Doses and during Continuous Treatment. Clin Pharmacokinet 6, 306–315 (1981). https://doi.org/10.2165/00003088-198106040-00005
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DOI: https://doi.org/10.2165/00003088-198106040-00005