Essential Pharmacology: Drug Mechanisms, Administration, and Interaction Risks

Diltiazem Administration and Uses

Diltiazem can be used in all types of angina. Its long-acting formulation is used in hypertension in cases where beta-blockers are contraindicated or ineffective.

Adrenaline's Systemic Effects in Shock

In the initial stages of shock, the body compensates for the loss of blood pressure by increasing sympathetic nervous system activity. This causes vasoconstriction, increased tension, and cardiac contraction.

Low Molecular Weight Heparin (LMWH) Administration

Special considerations must be taken into account when administering a low molecular weight heparin (LMWH):

• Intravenous Infusion: Monitor for symptoms of heat, pain, or redness at the puncture site.
• Subcutaneous Injection: Monitor for bruising or swelling. Administer the subcutaneous dose at the same time each day.

Oral Iron Supplementation: Dosing and Risks

Iron Administration Guidelines

It is recommended to space the administration of iron lactate and other drugs by at least 2 hours. It is usual to take them on an empty stomach to increase intestinal absorption.

Potential Side Effects of Iron

Immediate side effects include nausea and gastrointestinal irritation.

Risks of Iron Overdose (Hemochromatosis)

Overdoses can lead to hemochromatosis, which may result in:

• Developing cirrhosis and liver tumors.
• Tan pigmentation in the skin.
• Diabetes.
• Congestive heart failure and cardiac arrhythmias.
• Hypogonadism.

Proton Pump Inhibitors (PPIs)

Mechanism of Action and Therapeutic Effect

PPIs block the action of the enzyme (H+/K+ ATPase) that, under normal conditions, acts on gastric parietal cells and triggers the production and release of hydrochloric acid in the stomach. Common PPIs include Omeprazole, Lansoprazole, and Pantoprazole.

Administering Oral PPIs via NG Tube

Statement: Omeprazole oral dosage form may be given through an NG tube.

Response: Incorrect. These drugs are destroyed by stomach acid. Their dosage form is delayed-release, designed so the active ingredient is released in the small intestine. Therefore, the structure of the medication should not be altered for enteral administration.

Antacids: Function and Interactions

Do Antacids Inhibit Gastric Acid Secretion?

Statement: Antacids inhibit gastric acid secretion in parietal cells.

Response: Incorrect. Antacids do not inhibit the secretion of gastric acid; rather, they neutralize it locally through a buffer reaction.

Mechanisms of Antacid Drug Interactions

Antacids may interact with other substances through several mechanisms:

• Alkalinization of the Stomach: Affects the absorption of pH-dependent drugs.
• Slowing Gastric Emptying: Aluminum compounds, such as aluminum hydroxide, relax smooth muscle, potentially delaying the effects of drugs absorbed in the intestine.
• Adsorption of Molecules: Antacids can adsorb multiple molecules, leading to insoluble compounds that are not absorbed.

Why Separate Antacids from Other Medications?

Antacids should be taken separately from other drugs because of the potential for significant drug interactions (as detailed above).

Optimal Timing for Antacid Administration

Antacids are typically administered after eating because the presence of food increases the gastric pH (up to pH 5), providing a more suitable environment for their management and prolonged effect.

Saline Laxatives: Primary Side Effects

Dehydration Risk

Saline laxatives are powerful and can cause the emission of liquid stools within the first hour of ingestion. The deposition rate varies but can be as frequent as a liquid deposition every 15 minutes.

Other Common Side Effects

Abdominal pain and cramping.