Antacid

Indications

• Metabolic acidosis
• Acid-base imbalance
• Urinary alkalinization
• Treatment of certain poisonings
• Cardiac arrest in the context of metabolic acidosis

Dosage

Children: Refer to the BNF for Children for specific pediatric dosages, as they depend on the clinical condition

Adults: Refer to local guidelines and BNF for specific dosing recommendations as they may vary based on clinical condition and severity. General adult dosing for bicarbonate may range from 1 to 2 mEq/kg IV initially, followed by maintenance doses as needed.

Mechanism of action

Bicarbonate acts as a buffer that neutralizes excess acids in the body. It dissociates in solution to produce bicarbonate ions (HCO3-) which can react with hydrogen ions (H+) to form carbonic acid (H2CO3), subsequently leading to the production of carbon dioxide (CO2) and water (H2O). This process helps to raise the pH of the blood and other fluids, counteracting acidosis. Bicarbonate is involved in several metabolic pathways, including the urea cycle and various biosynthetic pathways.

Pharmacodynamics

Bicarbonate's primary pharmacodynamic effect is its ability to buffer hydrogen ions, thus increasing blood pH. This is essential in conditions such as metabolic acidosis, where the body accumulates excess acid. By raising blood pH, bicarbonate can help alleviate symptoms associated with acidemia, such as fatigue, confusion, and shortness of breath. Its effects can also influence the renal and respiratory systems to regulate acid-base homeostasis.

Pharmacokinetics

Bicarbonate is rapidly absorbed from the gastrointestinal tract. It is distributed throughout the body fluids, and its effects can be seen within minutes of administration. The kidneys play a significant role in bicarbonate homeostasis by reabsorbing bicarbonate from urine and excreting hydrogen ions. The elimination half-life can vary, depending on the patient's metabolic state and renal function.

Pregnancy

Use with caution. Consult with a healthcare provider before use.

Breast-feeding

Use with caution. Consult with a healthcare provider before use.

Storage

Store in a cool, dry place away from light.

Indications

• Gastric hyperacidity
• Heartburn
• Indigestion
• Gastritis
• Peptic ulcers

Dosage

Children: Refer to the BNF for Children for appropriate dosing information.

Adults: Refer to specific product guidelines for dosing, as it may vary based on formulation.

Mechanism of action

Trisilicate works by reacting with hydrochloric acid in the stomach to form neutral compounds, which reduces acidity. This action helps to alleviate symptoms of acid-related disorders by increasing the pH level in the stomach.

Pharmacodynamics

Trisilicate exhibits its therapeutic effects primarily through acid neutralization. By decreasing the acidity of gastric contents, it provides symptomatic relief from conditions such as gastritis, gastroesophageal reflux disease (GERD), and peptic ulcers. The onset of action is typically rapid, with effects lasting for a few hours.

Pharmacokinetics

The pharmacokinetics of trisilicate involve minimal systemic absorption since the drug primarily acts locally within the gastrointestinal tract. The compound is excreted unchanged in the feces. Its onset of action is usually within minutes after administration, with a duration of effect that can last several hours, depending on gastric emptying and the formulation used.

Pregnancy

Trisilicate is not recommended for use during pregnancy unless the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Trisilicate may be used during breastfeeding, but it is advisable to consult a healthcare professional before use.

Storage

Store in a cool, dry place, protected from light.