Lack of effect of ranitidine on the disposition of lignocaine.

The effect of pretreatment with ranitidine (150 mg twice daily for 5 days) on the disposition of lignocaine was examined in 10 healthy volunteers (five male, five female). Each subject received separate oral (250 mg) and intravenous (1.5 mg/kg) doses of lignocaine hydrochloride before and after ranitidine. Lignocaine systemic clearance was reduced by 9% (1.11 to 0.99 1 h-1 kg-1; P < 0.01) following ranitidine pretreatment. The volume of distribution at steady-state was reduced by 15% (3.34 to 2.85 1 kg-'; P < 0.005).Lignocaine oral clearance, elimination half-life and oral bioavailability were unchanged after ranitidine pretreatment. There was no sex difference in the effects of ranitidine pretreatment on lignocaine disposition. These results are consistent with small reductions in blood flow to the splanchnic and other vascular beds due to ranitidine.

Section: Parameters Of Lignocaine Dispositionsupporting

confidence: 72%

Section: Parameters Of Lignocaine Dispositioncontrasting

confidence: 56%

Section: Parameters Of Lignocaine Dispositionmentioning

confidence: 99%

See 1 more Smart Citation

The effect of ranitidine on the disposition of lignocaine.

Robson¹,

Wing²,

Miners³

et al. 1985

“…In therapeutics, a criterion for the selection of an more potent antagonist, ranitidine, appears not histamine H2-receptor antagonist may be the to have this property (Breen et al, 1982;Feely & knowledge that a clinically important drug Guy, 1983;Reimann et al, 1982;Watts et al, interaction is probable. Whereas cimetidine 1983).…”

Section: Introductionmentioning

confidence: 99%

Dose and concentration dependent effect of ranitidine on procainamide disposition and renal clearance in man.

Somogyi¹,

Bochner²

1984

The pharmacokinetics of oral procainamide (1 g) were investigated in six healthy subjects during chronic dosing with ranitidine 150 mg twice daily, and in three of the subjects when ranitidine 750 mg was administered over 12 h. The procainamide area under the plasma concentration‐time curve was significantly (PQ0.02) increased by ranitidine (27.761.5 vs 31.561.8 mg l‐1 h) with a significant reduction in renal clearance (379632 vs 309630 ml/min, PQ0.02). There was no change in half‐life. The N‐acetylprocainamide (NAPA) area under the plasma concentration‐time curve was also significantly (PQ0.02) elevated by ranitidine (8.661.2 vs 9.761.3 mg 1‐1 h) due to a reduction in renal clearance from 187630 to 168628 ml/min. The larger dose of ranitidine produced greater alterations in the procainamide and NAPA pharmacokinetics. Ranitidine reduced the absorption of procainamide by 10% and by 24% at the higher dose level. Two‐hourly renal clearance values of procainamide were significantly (PQ0.05) reduced in the 2 to 10 h period and for NAPA between 0 to 6 and 8 to 10 h. The larger ranitidine dose reduced the renal clearances of procainamide and NAPA over the control period at each 2‐hourly time period. The reductions in renal clearance are most likely mediated by competition for the renal tubular cationic secretory pathway. Clinical implications arising from this study suggest a reduction in procainamide dosage may be necessary in a small, select number of patients with high plasma ranitidine concentrations, e.g., the elderly; furthermore, failure of therapeutic response for some drugs may be due to ranitidine‐induced impaired gastrointestinal absorption.

“…These include antipyrine and aminopyrine (Henry et al, 1980), warfarin (Serlin et al, 1979), propranolol (Heagerty et al, 1982) theophylline (Jackson et al, 1981) and lignocaine . In contrast, ranitidine has no effect on the disposition of antipyrine and aminopyrine (Henry et al, 1980), warfarin (Serlin et al, 1981), propranolol (Heagerty et al, 1982), theophylline (Breen et al, 1982) or lignocaine (Feely & Guy, 1983). Both cimetidine (Feely et al, 1981) and ranitidine (Feely & Guy, 1982) reduce liver blood flow, a possible cause of decreased hepatic removal of drugs with high extraction ratios (Wilkinson & Shand, 1975).…”

Section: Introductionmentioning

confidence: 99%

Effects of ranitidine on the disposition of metoprolol.

Kelly¹,

Salem²,

Kinney³

et al. 1985

1 The effects of ranitidine on the pharmacokinetics of metoprolol were examined in two studies.2 In the first study, pharmacokinetics of single doses of metoprolol were examined in six subjects before, during and after ranitidine administration for 1 week. Peak concentrations of metoprolol were increased on ranitidine but its half-life and clearance were unaltered.3 In the second study, 12 subjects received metoprolol twice daily for 1 week; once with ranitidine and once with placebo. Ranitidine had no effects on the chronic-dose pharmacokinetics or pharmacodynamics of metoprolol. 4 The chronic dose study suggests no inhibition of the metabolism of metoprolol by ranitidine. The single dose study suggests, however, that some interaction of an as yet unknown nature, cannot be excluded.