What is the use and dosage of Adalat XL (nifedipine) 30mg in treating high blood pressure and angina?

Adalat XL 30mg: Clinical Use and Dosing

Adalat XL (nifedipine extended-release) 30mg is indicated for hypertension and angina, with dosing typically starting at 30mg once daily and titrating up to 30-90mg daily for hypertension or 30-180mg daily for angina based on therapeutic response. 1

Approved Indications

• Hypertension: FDA-approved as monotherapy or in combination with other antihypertensive agents 1
• Angina pectoris: Effective for chronic stable angina, particularly when beta-blockers are contraindicated or insufficient 2, 3

Dosing Guidelines

Hypertension

• Starting dose: 30mg once daily on an empty stomach 1
• Titration: Increase over 7-14 day intervals based on therapeutic efficacy and safety 1
• Usual maintenance: 30-60mg once daily 1
• Maximum: Doses above 90mg daily are not recommended 1

Angina Pectoris

• Slow-release formulation: 30-180mg daily 2, 3
• Extended-release provides 24-hour coverage with once-daily dosing 3

Administration Instructions

• Swallow tablets whole—do not bite, chew, or divide 1
• Take on empty stomach for optimal absorption 1
• Avoid grapefruit juice, which can increase nifedipine levels 2-fold through CYP3A4 inhibition 1

Role in Cardiovascular Disease Management

Hypertension with Coronary Artery Disease

Calcium channel blockers like nifedipine are added to or substituted for beta-blockers when blood pressure remains elevated, angina persists, or beta-blocker side effects/contraindications exist. 2

• Long-acting dihydropyridines (like Adalat XL) are preferred over non-dihydropyridines when combining with beta-blockers to avoid excessive bradycardia 2
• The INVEST trial showed equivalent cardiovascular outcomes between verapamil and atenolol-based regimens in hypertensive patients with chronic CAD 2

Angina Management

• Beta-blockers remain first-line for angina in patients with CAD 2
• Nifedipine is appropriate when beta-blockers are inadequate, contraindicated, or not tolerated 2
• Critical safety warning: Immediate-release nifedipine must be avoided in unstable angina/NSTEMI without concomitant beta-blockade due to increased adverse cardiovascular events 2, 3

Important Safety Considerations

Contraindications and Warnings

• Never use immediate-release nifedipine for acute situations—can cause precipitous blood pressure drops leading to MI or stroke 3, 4
• Avoid in decompensated heart failure or severe LV systolic dysfunction 2
• Contraindicated in recent MI or unstable angina without beta-blocker coverage 4

Common Side Effects

• Peripheral edema (dose-dependent): hypotension, dizziness, flushing, headache, nausea, constipation 2, 3
• Edema management: use lowest effective dose, consider switching to non-dihydropyridine CCB (verapamil/diltiazem) if appropriate 5

Special Populations

• Elderly patients: 36% higher Cmax and 70% greater average plasma concentration; longer elimination half-life (6.7h vs 3.8h in young patients) 1
• Hepatic impairment: Longer half-life and higher bioavailability; use with caution 1
• Renal disease: Exercise caution as absorption may be modified; protein binding greatly reduced 1

Clinical Pearls

• Extended-release formulation provides more consistent plasma concentrations and better safety profile than immediate-release 3
• Trough/peak blood pressure ratios range from 41-78% for diastolic and 46-91% for systolic, indicating sustained 24-hour effect 1
• If discontinuation is necessary, taper gradually under close supervision 1
• Nifedipine combines effectively with beta-blockers or ACE inhibitors for resistant hypertension 3
• Use submaximal doses of two drugs rather than maximal doses of single agents to minimize side effects 3