AMMONIUM CHLORIDE
Chemistry - An acid-forming salt, ammonium chloride occurs as colorless crystals or as white, fine or course, crystalline powder. It is somewhat hygroscopic, and has a cool, saline taste. Whendissolved in water, the temperature of the solution is decreased. One gram is soluble in approximately 3 ml of water at room temperature; 1.4 ml at 100°C. One gram is soluble in approximately100 ml of alcohol.
One gram of ammonium chloride contains 18.7 mEq of ammonium and chloride ions. Thecommercially available concentrate for injection (26.75%) contains 5 mEq of each ion per ml andcontains disodium edetate as a stabilizing agent. The pH of the concentrate for injection isapproximately 5. Synonyms for ammonium chloride include muriate of ammonia and sal ammoniac.
Ammonium chloride should not be titrated with strong oxidizing agents (e.g., potassium chlorate)as explosive compounds may result.
Ammonium chloride is reported to be physically compatible with all commonly used IV replacement fluids and potassium chloride.
It is incompatible with: codeine phosphate, dimenhydrinate, methadone HCl, nitrofurantoinsodium, sulfisoxazole diolamine, and warfarin sodium. It is also reportedly incompatible with alkalis and their hydroxides.
The excess chloride ions presented to the kidney, are not completely reabsorbed by the tubulesand are excreted with cations (principally sodium) and water. This diuretic effect is usually compensated for by the kidneys after a few days of therapy.
Uses, Indications - The veterinary indications for ammonium chloride are as a urinary acidifyingagent to help prevent and dissolve certain types of uroliths (e.g., struvite), to enhance renal excretionof some types of toxins (e.g., strontium) or drugs (e.g., quinidine), or to enhance the efficacy ofcertain antimicrobials (e.g., chlortetracycline, methenamine mandelate, nitrofurantoin, oxytetracycline, penicillin G or tetracycline) when treating urinary tract infections. Ammoniumchloride has also been used intravenously for the rapid correction of metabolic alkalosis.
Contraindications/Precautions - Ammonium chloride is contraindicated in patients with severehepatic disease as ammonia may accumulate and cause toxicity. In general, ammonium chlorideshould not be administered to uremic patients as it may intensify the metabolic acidosis alreadyexisting in some of these patients. Ammonium chloride should not be used alone in patients withsevere renal insufficiency and metabolic alkalosis secondary to vomiting hydrochloric acid assodium depletion can occur. In these cases, sodium chloride repletion with or without ammoniumchloride administration should be performed to correct both sodium and chloride deficits.
Ammonium chloride is contraindicated in patients with urate calculi or respiratory acidosis and hightotal CO2 and buffer base. Ammonium chloride cannot alone correct hypochloremia withsecondary metabolic alkalosis due to intracellular potassium chloride depletion. Potassium chloridemust be administered to these patients.
Do not administer subcutaneously, rectally or intraperitoneally.
Use ammonium chloride with caution in patients with pulmonary insufficiency or cardiac edema.
Overdosage - Symptoms of overdosage may include: nausea, vomiting, excessive thirst, hyperventilation, bradycardias or other arrhythmias, and progressive CNS depression. Profound acidosisand hypokalemia may be noted on laboratory results.
Treatment should consist of correcting the acidosis by administering sodium bicarbonate orsodium acetate intravenously. Hypokalemia should be treated by using a suitable oral (if possible)potassium product. Intense acid-base and electrolyte monitoring should be performed on anongoing basis until the patient is stable.
The aminoglycosides (e.g., gentamicin) and erythromycin are more effective in an alkalinemedium; urine acidification may diminish these drugs effectiveness in treating bacterial urinary tractinfections.
One gram of ammonium chloride contains 18.7 mEq of ammonium and chloride ions. Thecommercially available concentrate for injection (26.75%) contains 5 mEq of each ion per ml andcontains disodium edetate as a stabilizing agent. The pH of the concentrate for injection isapproximately 5. Synonyms for ammonium chloride include muriate of ammonia and sal ammoniac.
Storage, Stability, Compatibility
Ammonium chloride for injection should be stored at roomtemperature; avoid freezing. At low temperatures, crystallization may occur; it may be resolubolizedby warming to room temperature in a water bath.Ammonium chloride should not be titrated with strong oxidizing agents (e.g., potassium chlorate)as explosive compounds may result.
Ammonium chloride is reported to be physically compatible with all commonly used IV replacement fluids and potassium chloride.
It is incompatible with: codeine phosphate, dimenhydrinate, methadone HCl, nitrofurantoinsodium, sulfisoxazole diolamine, and warfarin sodium. It is also reportedly incompatible with alkalis and their hydroxides.
Pharmacology - AMMONIUM CHLORIDE
The acidification properties of ammonium chloride are caused by its dissociationinto chloride and ammonium ions in vivo. The ammonium cation is converted by the liver to ureawith the release of a hydrogen ion. This ion combines with bicarbonate to form water and carbondioxide. In the extracellular fluid, chloride ions combine with fixed bases and decrease the alkalinereserves in the body. The net effects are decreased serum bicarbonate levels and a decrease in bloodand urine pH.The excess chloride ions presented to the kidney, are not completely reabsorbed by the tubulesand are excreted with cations (principally sodium) and water. This diuretic effect is usually compensated for by the kidneys after a few days of therapy.
Uses, Indications - The veterinary indications for ammonium chloride are as a urinary acidifyingagent to help prevent and dissolve certain types of uroliths (e.g., struvite), to enhance renal excretionof some types of toxins (e.g., strontium) or drugs (e.g., quinidine), or to enhance the efficacy ofcertain antimicrobials (e.g., chlortetracycline, methenamine mandelate, nitrofurantoin, oxytetracycline, penicillin G or tetracycline) when treating urinary tract infections. Ammoniumchloride has also been used intravenously for the rapid correction of metabolic alkalosis.
Pharmacokinetics - AMMONIUM CHLORIDE
No information was located on the pharmacokinetics of this agent in veterinary species. In humans, ammonium chloride is rapidly absorbed from the GI.Contraindications/Precautions - Ammonium chloride is contraindicated in patients with severehepatic disease as ammonia may accumulate and cause toxicity. In general, ammonium chlorideshould not be administered to uremic patients as it may intensify the metabolic acidosis alreadyexisting in some of these patients. Ammonium chloride should not be used alone in patients withsevere renal insufficiency and metabolic alkalosis secondary to vomiting hydrochloric acid assodium depletion can occur. In these cases, sodium chloride repletion with or without ammoniumchloride administration should be performed to correct both sodium and chloride deficits.
Ammonium chloride is contraindicated in patients with urate calculi or respiratory acidosis and hightotal CO2 and buffer base. Ammonium chloride cannot alone correct hypochloremia withsecondary metabolic alkalosis due to intracellular potassium chloride depletion. Potassium chloridemust be administered to these patients.
Do not administer subcutaneously, rectally or intraperitoneally.
Use ammonium chloride with caution in patients with pulmonary insufficiency or cardiac edema.
Adverse Effects, Warnings
Development of metabolic acidosis (sometimes severe) can occurunless adequate monitoring is performed. When used intravenously, pain at the injection site candevelop; slow administration lessens this effect. Gastric irritation, nausea and vomiting can beassociated with oral dosing of the drug.Overdosage - Symptoms of overdosage may include: nausea, vomiting, excessive thirst, hyperventilation, bradycardias or other arrhythmias, and progressive CNS depression. Profound acidosisand hypokalemia may be noted on laboratory results.
Treatment should consist of correcting the acidosis by administering sodium bicarbonate orsodium acetate intravenously. Hypokalemia should be treated by using a suitable oral (if possible)potassium product. Intense acid-base and electrolyte monitoring should be performed on anongoing basis until the patient is stable.
Drug Interactions
Urine acidification may increase the renal excretion of quinidine.The aminoglycosides (e.g., gentamicin) and erythromycin are more effective in an alkalinemedium; urine acidification may diminish these drugs effectiveness in treating bacterial urinary tractinfections.