The pharmacokinetics of Nimodipine were studied in healthy volunteers and in patients with subarachnoid hemorrhage (SAH) following cerebral aneurysm rupture. Nimodipine was absorbed rapidly. After an oral dose of 120 mg an average maximal plasma concentration 106 micrograms/l was recorded 45 to 60 minutes later. During a 7-day oral therapy with 40 mg t.i.d. no accumulation or change in the absorption or elimination kinetics occurred. After i.v. administration a biphasic elimination with half lives of 7 min and 1 hour was observed. In patients with subarachnoid hemorrhage receiving a continuous infusion of 2 mg/hour the mean nimodipine plasma concentrations ranged between 36 and 72 micrograms/l. Subsequent oral dose of 60 mg q.i.d. to the same patients resulted in concentrations ranging between 17 to 42 micrograms/l on the average one hour after the dosage. Mean cerebrospinal fluid (CSF) levels amounted to 0.3 +/- 0.2 microgram/l in patients whose mean plasma concentrations were 76.9 +/- 34.0 micrograms/l.
Nifedipine has been proven to be effective and safe in the treatment of primary oesophageal motility disorders which can cause angina-like chest pain and/or dysphagia. The effects of the calcium channel blockers nifedipine, nitrendipine, nimodipine and nisoldipine on oesophageal smooth muscle function in healthy male volunteers were studied by oesophageal manometry using the rapid pull-through-technique, in two randomized, double-blind crossover studies. Lower oesophageal sphincter pressure, oesophageal contraction amplitude and duration after a wet swallow (measured 5 cm and 10 cm above the lower oesophageal sphincter) were determined 30 min before and at 10 minute intervals up to 90 min after the administration of nimodipine and up to 120 min after nifedipine, nitrendipine and nisoldipine. The plasma drug concentration was measured at baseline (-15 min) and in parallel with the manometric measurements. Compared to placebo, lower oesophageal sphincter pressure was significantly decreased by 24% by nifedipine and 17% by nimodipine, whereas the effects of nitrendipine (decrease of 15%) and nisoldipine (9%) were not significant. Nifedipine significantly decreased by 17% the oral contraction amplitude compared to placebo and nimodipine by 11%. The duration of the contraction amplitudes was not altered. The decrease in sphincter pressure was correlated with the corresponding plasma drug levels of nifedipine r = 0.92, nitrendipine r = 0.80 and nisoldipine r = 0.79. Nimodipine showed no such correlation.(ABSTRACT TRUNCATED AT 250 WORDS)
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