Ammonium Chloride
Indications: Alkalosis, metabolic Hypochloremia
DESCRIPTION: Odourless, hygroscopic, white, crystalline powder or colour-
less crystals. Each g represents 18.69 mmol of chloride.
Freely soluble in water and in glycerol, and more so in boil-
ing water: sparingly soluble in alcohol. A 5% solution in wa-
ter has a pH of 4.6 to 6.0. Store in airtight containers.
Ammonium chloride injection, USP, 100 mEq, is a sterile, nonpyrogenic solution of ammonium chloride (NH4Cl) in water for injection administered (after dilution) by the intravenous route. Each mL contains 267.5 mg of ammonium chloride (5 mEq of ammonium and 5 mEq of chloride) and 2.0 mg of edetate disodium (anhydrous) added as a stabilizer. Approximate ph 5.0, adjusted with hydrochloric acid. 10 mOsm/mL (calc). It is intended to be used only after dilution in a larger volume of isotonic (0.9%) sodium chloride injection.
The solution contains no bacteriostat, antimicrobial agent or added buffer (except for ph adjustment) and is intended only for dilution as a single-dose additive. When smaller doses are required the unused portion should be discarded with the entire additive unit.
Ammonium chloride injection, is an electrolyte replenisher and systemic acidifier.
Ammonium chloride, is chemically designated NH4Cl, colorless crystals or white granular powder freely soluble in water.
CLINICAL PHARMACOLOGY:
The ammonium ion (NH4+) in the body plays an important role in the maintenance of acid-base balance. The kidney uses ammonium (NH4+) in place of sodium (Na+) to combine with fixed anions in maintaining acid-base balance, especially as a homeostatic compensatory mechanism in metabolic acidosis.
When a loss of hydrogen ions (H+) occurs and serum chloride (Cl-) decreases, sodium is made available for combination with bicarbonate (HC03-). This creates an excess of sodium bicarbonate (NaHC03) which leads to a rise in blood ph and a state of metabolic alkalosis.
The therapeutic effects of ammonium chloride depend upon the ability of the kidney to utilize ammonia in the excretion of an excess of fixed anions and the conversion of ammonia to urea by the liver, thereby liberating hydrogen (H+) and chloride (Cl-) ions into the extracellular fluid.
Adverse Effects and Treatment
Ammonium salts are irritant to the gastric mucosa and may
produce nausea and vomiting particularly in large doses.
Large doses of ammonium chloride may cause a profound ac-
idosis and hypokalaemia which should be treated symptomat-
ically. Intravenous administration of ammonium chloride
may cause pain and irritation at the site of injection, which
may be decreased by slowing the rate of infusion.
Excessive doses of ammonium salts, particularly if adminis-
tered by rapid intravenous injection, may give rise to hepatic
encephalopathy due to the inability of the liver to convert the
increased load of ammonium ions to urea.
Rapid intravenous administration of ammonium chloride may be accompanied by pain or irritation at the site of injection or along the venous route.
Reactions which may occur because of the solution or the technique of administration include febrile response, infection at the site of injection, venous thrombosis or phlebitis extending from the site of injection, extravasation and hypervolemia (from large volume diluent).
If an adverse reaction does occur, discontinue the infusion, evaluate the patient, institute appropriate therapeutic countermeasures and save the remainder of the fluid for examination if deemed necessary.
INDICATIONS AND USAGE:
Ammonium chloride injection, after dilution in isotonic sodium chloride injection, may be indicated in the treatment of patients with (1) hypochloremic states and (2) metabolic alkalosis.
CONTRAINDICATIONS:
Ammonium chloride is contraindicated in patients with severe impairment of renal or hepatic function.
Ammonium chloride should not be administered when metabolic alkalosis due to vomiting of hydrochloric acid is accompanied by loss of sodium (excretion of sodium bicarbonate in the urine).
PRECAUTIONS:
Ammonium salts are contra-indicated in the presence of im-
paired hepatic or renal function.
Do not administer unless the solution is clear and seal is intact. Discard unused portion.
Patients receiving ammonium chloride should be constantly observed for symptoms of ammonia toxicity (pallor, sweating, retching, irregular breathing, bradycardia, cardiac arrhythmias, local and general twitching, tonic convulsions and coma).
It should be used with caution in patients with high total CO2 and buffer base secondary to primary respiratory acidosis.
Intravenous administration should be slow to avoid local irritation and toxic effects.
When exposed to low temperatures, concentrated solutions of ammonium chloride may crystallize. If crystals are observed, the vial should be warmed to room temperature in a water bath prior to use.
Pregnancy Category C: Animal reproduction studies have not been conducted with ammonium chloride. It is also not known whether ammonium chloride can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Ammonium chloride should be given to a pregnant woman only if clearly needed.
OVERDOSAGE:
Overdosage of ammonium chloride has resulted in a serious degree of metabolic acidosis, disorientation, confusion and coma. Should metabolic acidosis occur following overdosage, the administration of an alkalinizing solution such as sodium bicarbonate or sodium lactate will serve to correct the acidosis.
DOSAGE AND ADMINISTRATION:
Ammonium chloride injection, is administered intravenously and must be diluted before use. Solutions for intravenous infusion should not exceed a concentration of 1% to 2% of ammonium chloride.
Dosage is dependent upon the condition and tolerance of the patient. It is recommended that the contents of one to two vials (100 to 200 mEq) be added to 500 or 1000 mL of isotonic (0.9%) sodium chloride injection. The rate of intravenous infusion should not exceed 5 mL per minute in adults (approximately 3 hours for infusion of 1000 mL). Dosage should be monitored by repeated serum bicarbonate determinations.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
Protect from freezing and extreme heat.