Acidifying drugs
Acidifying drugs
Acidifying drugs are used to correct metabolic alkalosis. These include:
- acetazolamide (used in treatment of acute mountain sickness)
- ammonium chloride.
Ascorbic acid, along with ammonium chloride, serves as a urinary acidifier.
Pharmacokinetics
The action of most acidifying drugs is immediate.
Absorption, metabolism, and excretion
Orally administered ammonium chloride is absorbed completely in 3 to 6 hours. It’s metabolized in the liver to form urea, which is excreted by the kidneys.
Break it down
Acetazolamide inhibits the enzyme carbonic anhydrase, which blocks hydrogen ion secretion in the renal tubule, resulting in increased excretion of bicarbonate and a lower pH. Acetazolamide also acidifies urine but may produce metabolic acidosis in normal patients.
Pharmacodynamics
Acidifying drugs have several actions:
- Ammonium chloride lowers the blood pH after being metabolized to urea and to hydrochloric acid, which provides hydrogen ions to acidify the blood or urine.
- Ascorbic acid directly acidifies urine, providing hydrogen ions and lowering urine pH.
- Acetazolamide increases the excretion of bicarbonate, lowering blood pH.
Pharmacotherapeutics
A patient with metabolic alkalosis requires therapy with an acidifying drug that provides hydrogen ions; such a patient may need chloride ion therapy as well.
Safe and easy
Most patients receive both types of ions in oral or parenteral doses of ammonium chloride, a safer drug that’s easy to prepare.
Kidney concerns
In patients with renal dysfunction, acetazolamide may be ineffective and cause loss of potassium in urine.
Drug interactions
Acidifying drugs don’t cause clinically significant drug interactions. However, concurrent use of ammonium chloride and spironolactone may cause increased systemic acidosis. (See Adverse reactions to acidifying drugs.)
Adverse reactions to acidifying drugs
Adverse reactions to acidifying drugs are usually mild, such as GI distress. Overdose may lead to acidosis.
Acetazolamide
- Drowsiness
- Seizures
- Anorexia
- Nausea and vomiting
- Diarrhea
- Altered taste
- Aplastic anemia
Ammonium chloride
- Metabolic acidosis and loss of electrolytes, especially potassium (with large doses)
Ascorbic acid
- GI distress (with high doses)
- Hemolytic anemia (in a patient with glucose-6-phosphate dehydrogenase deficiency)
Thanks for your visit..!