Interactions between k-phos-original(potassium acid phosphate) and Dextroamphetamine (dextroamphetamine)
dextroamphetamine and potassium acid phosphate (Moderate Drug-Drug)
MONITOR: Urinary acidifying agents such as ammonium chloride and sodium acid phosphate may lower the blood levels and efficacy of amphetamines. Acidifying the urine has been reported to increase the concentration of the ionised species of the amphetamine molecule, thereby inhibiting renal tubular absorption and increasing its urinary excretion. In one study, approximately 55% of an amphetamine dose was excreted unchanged when the urine was acidic, versus less than 3% when the urine was alkaline. Amphetamine half-life has also been reported to shorten by one-half or more when urine is acidic rather than alkaline. Acidification of the urine has been employed successfully in the treatment of amphetamine overdose.
MANAGEMENT: Patients receiving an amphetamine in combination with urinary acidifying agents should be monitored for potentially diminished pharmacologic response to the amphetamine.
