Nonprescription chlorpheniramine maleate and submaximal exercise responses.
OBJECTIVE
To determine if a single, over-the-counter dose of the H1 antagonist chlorpheniramine maleate (CM) alters total peripheral resistance (TPR) and oxygen uptake (VO2) during submaximal exercise.


METHODS
The study was a prospective, longitudinal, double-blind, random crossover analysis of the cardiovascular and respiratory responses to a single bout of moderately intense exercise.


METHODS
Exercise tests were conducted in an exercise laboratory equipped with expired gas analysis and bioelectrical impedance cardiographic monitoring capabilities.


METHODS
Subjects were 18 (9 men, 9 women) volunteers (age=29.5+/-3.6yrs; weight=70.7+/-1.1kg), free from exercise-limiting pathology and rhinitis.


METHODS
Each subject completed a maximal exercise tolerance test on the cycle ergometer followed by two randomly ordered submaximal exercise tests at a power output of 50% of the peak power attained on the maximal test: the first, 2 hours after ingesting 4mg of CM, the second, 2 hours after ingesting a placebo. The submaximal exercise tests lasted 20min and data were recorded at 5, 10, 15, and 20min of exercise during both the CM and placebo tests. Tests were completed approximately 48 hours apart.


RESULTS
Average VO2 was 1,488+/-367mL/min for the CM test and 1,477+/-351mL/min for the placebo test. TPR was 12.3+/-7.4PRU for the CM and 11.3+/-4.5PRU for the placebo tests. Analysis of variance revealed that these scores were statistically similar.


CONCLUSIONS
A single over-the-counter dose of CM does not alter TPR or VO2 during submaximal exercise.
Department of Health Promotion and Human Performance, School of Pharmacy, University of Toledo, OH, USA.
M F
MF
Peterlin
R E
RE
Keyser
F F
FF
Andres
G
G
Sherman
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002744:Chlorpheniramine / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005080:Exercise Test / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D004366:Nonprescription Drugs / Q000494:pharmacology*; D010100:Oxygen / Q000097:blood*; D011446:Prospective Studies; D014655:Vascular Resistance / Q000187:drug effects*
D006634:Histamine H1 Antagonists; D004366:Nonprescription Drugs; D002744:Chlorpheniramine; D010100:Oxygen