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Methadone maintenance: Effect of urinary pH on renal clearance in chronic high and low doses
Author(s) -
Bellward Gail D.,
Warren P. M.,
Howald W.,
Axelson James E.,
Abbott Frank S.
Publication year - 1977
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1002/cpt197722192
Subject(s) - methadone , renal function , urinary system , clearance , medicine , metabolite , urine , urology , clearance rate , endocrinology , pharmacology
The subjects were 12 male patients stabilized on methadone for many months or years. A comparison was made of the plasma levels and renal clearance of methadone between patients on “high” doses (80 to 110 mg/day) and those on “low” doses (15 to 40 mg/day). A general trend to higher renal clearance was seen in the “high”‐dose group, but on more detailed examination there was a direct correlation only when the patients were categorized by urinary pH. At low pHs, there was nearly a 3‐fold increase in renal clearance which was associated with a decreased major metabolite to methadone ratio. No evidence for a difference in rate of metabolism between the two groups was found nor were there differences in hepatic function. It was concluded that urinary pH was a major factor in renal clearance of methadone.