Abstract
Dose tolerance and pharmacokinetic studies of pseudoephedrine sustained action capsules were performed in thirty-three adult male subjects who received either 120 mg or 150 mg capsules every twelve hours for seven consecutive days in a double-blind parallel design study. Although only one subject in the 150 mg group was discontinued prematurely from this study, a large number of side effects typical of CNS stimulation were seen. A placebo effect might account for a portion of these complaints, however symtoms evaluated as being due to drug were significantly more severe and persistent in the 150 mg group. Pulse rates showed a persistent and significant increase while systolic and diastolic blood pressure fell from the baseline values in both groups. A pharmacokinetic analysis of the pseudoephedrine plasma concentration-time data provided estimates of half-life and the volume of distribution/availability ratio. The values obtained were in good agreement with values reported by others. Half-life was not influenced by urine pH probably as a result of the narrow range of urine pHs observed in the subjects. Calculations of relative bioavailability suggest that the 120 mg capsule formulation has a 30% greater bioavailability compared to the 150 mg capsule.
Original language | English (US) |
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Pages (from-to) | 253-259 |
Number of pages | 7 |
Journal | European Journal of Clinical Pharmacology |
Volume | 14 |
Issue number | 4 |
DOIs | |
State | Published - Jul 1 1978 |
Keywords
- Pseudoephedrine
- bioavailability
- multiple oral dosing
- side effects
ASJC Scopus subject areas
- Pharmacology
- Pharmacology (medical)