Pseudoephedrine Ammonium chloride

In a study with human subjects, whose urine pH was controlled with sodium bicarbonate and ammonium chloride, it was found that 10-25% of the administered pseudoephedrine hydrochloride was metabolized to norpseudoephedrine and the elimination of pseudoephedrine and norpseudoephedrine was related to urine pH. As the urine pH increased, the serum half-life of pseudoephedrine and norpseudoephedrine increased.15 In another similar study it was found that a decrease... 

Methylpentynol Bulk TLC extracted 50% EtOH (15 ml) RT, 30 min, centrifuged, filtered. ISTD-benzyltriethyl-ammonium chloride cm 75 ID, 28 kV Silica 0.005M barium hydroxide (pH 10) CHCI3-acctonc (4 1) KMnO, methylpseudo-ephedrine 5 min, pseudoephedrine 6.2 min, ephedrine 6.8 min, methylephedrine 7.8 min. norpseudoephedrine 8.1 min, norephedrine 8.8 min GC 2] [1]... 

The rate at which any of the enantiomers is eliminated depends upon the urinary pH. At high pHs, excretion time is prolonged. At low pH ranges, excretion is accelerated. In controlled laboratory studies, where volunteer subjects were given either bicarbonate or ammonium chloride, the higher the urine pH, the more slowly the ephedrine and pseudoephedrine were excreted. Conversely, when the urine pH is low, excretion is accelerated (71). The importance of these observations is hard to assess, because without the addition of bicarbonate, urine pH values in the general population rarely approach 8.0. A study of pseudoephedrine pharmacokinetics in 33 volunteers who were not treated with drugs to alter urine pH found that these parameters could not be... 

Alkalinisation of the urine (e.g. by sodium bicarbonate) causes retention of ephedrine and pseudoephedrine by the kidneys, leading to the possible development of toxicity (tremors, anxiety, insomnia, tachycardia). Acidification of the urine (e.g. with ammonium chloride) has the opposite effect. 

This confirms an earlier study, in which it was found that at a urinary pH of 8, the half-life of pseudoephedrine was 16, 9.2, and 15 hours in 3 subjects, respectively. At a urinary pH of about 5, the half-life was 4.8,3, and 6.4 hours, respectively. Sodium bicarbonate was given to raise urinary pH and ammonium chloride to lower urinary pH. 

Acidification of the urine with ammonium chloride increases the loss of ephedrine and pseudoephedrine in the urine and could be exploited in cases of drug overdosage. 

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