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Name: Diltiazem hydrochloride

Pregnancy Category C

Drug classes

  • Calcium channel-blocker
  • Antianginal drug
  • Antihypertensive

Therapeutic actions

Inhibits the movement of calcium ions across the membranes of cardiac and arterial muscle cells, which results in the depression of impulse formation in specialized cardiac pacemaker cells, slowing of the velocity of conduction of the cardiac impulse, depression of myocardial
contractility, and dilation of coronary arteries and arterioles and peripheral arterioles; these effects lead to decreased cardiac work, decreased cardiac energy consumption, and in patients with vasospastic (Prinzmetal's) angina, increased delivery of oxygen to myocardial cells.


  • Angina pectoris due to coronary artery spasm (Prinzmetal's variant angina)
  • Effort-associated angina; chronic stable angina in patients not controlled by beta-adrenergic blockers, nitrates
  • Essential hypertension (sustained release)
  • Paroxysmal supraventricular tachycardia (parenteral)


Allergy to diltiazem, impaired hepatic or renal function, sick sinus syndrome, heart block (second or third degree), lactation.

Adverse effects

  • CNS: Dizziness, lightheadedness, headache, asthenia, fatigue
  • GI: Nausea, hepatic injury
  • CV: Peripheral edema, hypotension, arrhythmias, bradycardia, AV block, asystole
  • Dermatologic: Flushing, rash

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