1. Clinical Overview
A fixed-dose combination of essential electrolyte salts, Magnesium Citrate and Potassium Citrate, primarily used for the prevention and treatment of hypomagnesemia and hypokalemia, and as an alkalinizing agent in conditions like renal tubular acidosis and uric acid/calcium oxalate nephrolithiasis. It replenishes intracellular magnesium and potassium ions while increasing urinary pH and citrate excretion.
| Onset | Duration | Bioavailability |
|---|---|---|
| Oral: 1-2 hours for electrolyte correction; Urinary alkalinization begins within 1 hour, peaks at 3-4 hours. | Approximately 4-6 hours for urinary alkalinization; sustained electrolyte correction depends on daily dosing. | Magnesium Citrate: ~25-30% (highly variable, depends on magnesium status). Potassium Citrate: >90%. |
2. Mechanism of Action
The combination works via two primary mechanisms: 1) Replenishment of intracellular cations (Mg2+ and K+), and 2) Systemic and urinary alkalinization. After absorption, citrate is metabolized to bicarbonate, raising blood and urinary pH. This increased pH promotes the dissociation of citric acid into citrate ions, which chelate calcium in the urine, inhibiting the crystallization of calcium oxalate and calcium phosphate. Alkaline urine also increases the solubility of uric acid. Magnesium directly inhibits calcium oxalate crystal growth and aggregation in urine.
3. Indications & Uses
- Prevention and treatment of hypomagnesemia
- Prevention and treatment of hypokalemia
- Prevention of calcium oxalate and uric acid nephrolithiasis (kidney stones)
- Management of renal tubular acidosis (distal type)
4. Dosage & Administration
Adult Dosage: 1-2 tablets twice or thrice daily, or as directed by the physician. Typical dose for stone prophylaxis: 1 tablet TID with meals. For hypokalemia/hypomagnesemia: Dose titrated based on serum levels.
Administration: Take with or immediately after a meal with a full glass of water (200-250 mL). Do NOT crush, chew, or suck the tablet. Swallow whole to avoid local irritation of mouth, esophagus, and stomach. Maintain adequate fluid intake (2.5-3 L/day) unless contraindicated.
5. Side Effects
Common side effects may include:
- Nausea
- Abdominal discomfort or pain
- Diarrhea (especially with magnesium component)
- Mild gastrointestinal irritation
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Potassium-Sparing Diuretics (Spironolactone, Amiloride) | Additive risk of severe hyperkalemia | Major |
| ACE Inhibitors (Ramipril, Enalapril) / ARBs (Losartan, Telmisartan) | Increased risk of hyperkalemia | Major |
| NSAIDs (Ibuprofen, Diclofenac) | May reduce renal function, increasing risk of hyperkalemia | Moderate |
| Digoxin | Hypomagnesemia and hypokalemia potentiate digoxin toxicity. This combination corrects that, but rapid over-correction can alter digoxin effect. | Moderate |
| Quinolone Antibiotics (Ciprofloxacin, Levofloxacin), Tetracyclines, Bisphosphonates (Alendronate) | Magnesium can form insoluble complexes, drastically reducing absorption of these drugs. Separate administration by at least 2-4 hours. | Major |
| Anticholinergics / Opioids | May increase risk of GI mucosal injury by delaying tablet transit. | Moderate |
7. Patient Counselling
- DO take the tablet whole with a full glass of water during or after a meal.
- DO report any signs of GI bleeding (black tarry stools, vomiting blood).
- DO maintain adequate fluid intake as advised by your doctor.
- DO keep regular appointments for blood tests (potassium, magnesium, creatinine).
- DO NOT crush, chew, or suck the tablet.
- DO NOT take this medication if you have difficulty swallowing tablets.
- DO NOT use salt substitutes (often high in potassium) while on this therapy without consulting your doctor.
8. Toxicology & Storage
Overdose: Primarily symptoms of hyperkalemia (muscle weakness, flaccid paralysis, paresthesia, cardiac arrhythmias like bradycardia, heart block, asystole) and hypermagnesemia (hypotension, facial flushing, nausea, respiratory depression, coma, cardiac arrest). GI symptoms like severe diarrhea may also occur.
Storage: Store below 30°C in a cool, dry place. Protect from moisture and direct sunlight. Keep the container tightly closed. Keep out of reach of children.