Hydrochlorothiazide 12.5mg Tablets: Generic Information
Hydrochlorothiazide 12.5mg tablets are themselves a generic medication and do not have a separate generic version. Hydrochlorothiazide (HCTZ) is the generic name for this thiazide diuretic medication.
Medication Details
Hydrochlorothiazide 12.5mg is available as:
- A generic medication (no brand name equivalent needed)
- White capsules/tablets (depending on manufacturer)
- FDA-approved for hypertension treatment 1
Physical Characteristics
- Typically supplied as hard gelatin capsules with opaque white cap and body
- Often imprinted with manufacturer-specific markings (e.g., "U" on cap and "130" on body in grey ink) 1
- Available in bottles of 100,500, or 1,000 tablets 1
Clinical Information
Dosing
- Starting dose is typically 12.5mg daily
- May be titrated up to 25-50mg daily if needed for blood pressure control 2
- Lower doses (12.5-25mg) are generally recommended as higher doses add little additional antihypertensive efficacy while increasing side effect risk 2
Efficacy Considerations
- Hydrochlorothiazide has been shown to be less potent than chlorthalidone on a milligram-per-milligram basis 3
- Equivalent doses: 25mg hydrochlorothiazide ≈ 12.5mg chlorthalidone 4
- Hydrochlorothiazide has a shorter duration of action (6-12 hours) compared to chlorthalidone (40-60 hours) 5, 4
Common Combinations
Hydrochlorothiazide is frequently used in fixed-dose combinations with:
- ACE inhibitors (e.g., lisinopril-hydrochlorothiazide)
- ARBs (e.g., losartan-hydrochlorothiazide)
- Beta-blockers (e.g., metoprolol-hydrochlorothiazide)
- Potassium-sparing diuretics (e.g., triamterene-hydrochlorothiazide) 2
Side Effects and Monitoring
Common Side Effects
- Electrolyte disturbances (hypokalemia, hyponatremia)
- Increased uric acid levels
- Glucose intolerance 2, 5
Monitoring Recommendations
- Regular monitoring of electrolytes, particularly in elderly patients
- Blood pressure monitoring to assess efficacy
- Periodic assessment of glucose levels in diabetic patients 5
Risk Factors for Adverse Effects
- Elderly female patients are at higher risk for hyponatremia
- Patients with low body weight
- Concurrent use of other medications that can cause electrolyte disturbances 5
Storage Information
- Store at 20° to 25°C (68° to 77°F)
- Protect from light, moisture, and freezing
- Keep container tightly closed 1
Practical Considerations
- Hydrochlorothiazide is widely prescribed (approximately 50 million prescriptions annually) 3
- Available at most pharmacies and typically covered by insurance plans
- Often available on discount generic medication lists at major pharmacies
- Prescription required (Rx only) 1
Remember that while hydrochlorothiazide is effective for blood pressure control, some evidence suggests chlorthalidone may have superior outcomes for cardiovascular event reduction 3, 4. However, hydrochlorothiazide remains widely used due to its availability, tolerability at lower doses, and extensive clinical experience.