**Question:** Which of the following cause
metabolic alkalosis?

A. Diuretic drugs
B. Chronic kidney disease
C. Cough suppressants
D. Alcohol abuse

**Core Concept:**
Metabolic alkalosis is a state of excess bicarbonate ions in the blood, leading to a pH increase and a decrease in hydrogen ion concentration. It is a consequence of a loss of hydrogen ions or an increase in bicarbonate ions. The correct answer should explain factors contributing to this imbalance in pH and hydrogen ion concentration.

**Why the Correct Answer is Right:**

D. Alcohol abuse can lead to both diuretic effects and renal tubular dysfunction, contributing to the development of achlorhydria (loss of hydrochloric acid) and increased bicarbonate reabsorption in the renal tubules. This results in hydrogen ion concentration decrease and bicarbonate ions increase, leading to the development of a state of hyperalkalemia and hypocapnia, which is characteristic of a patient with alcohol-induced alkalosis.

**Why Each Wrong Option is Incorrect:**

A. Diuretic drugs typically increase urine volume by promoting water excretion without a significant change in electrolyte balance, thus not leading to alkalosis.

B. Chronic kidney disease may lead to a variety of electrolyte imbalances, including acidosis or hypokalemia, but not necessarily alkalosis.

C. Cough suppressants (e.g., codeine) primarily affect respiratory rate and not renal function or electrolyte balance, thus they do not cause alkalosis.

**Clinical Pearl:**

Achlorhydria is a condition where gastric acid secretion is reduced, typically due to medications like alcohol or H2-receptor antagonists. It leads to alkalosis due to the loss of hydrochloric acid in the urine and increased bicarbonate reabsorption in the renal tubules. This is a crucial concept for understanding the pathophysiology of alkalosis and can help you differentiate between various clinical scenarios.