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diltiazem hydrochloride

Adizem (UK), Angitil (UK), Apo-Diltiaz (CA), Apo-Diltiazem (CA), Calcicard (UK), Cardizem, Cardizem CD, Cardizem LA, Cartia XT, Dilacor-XR, Dilcardia (UK), Dilt-CD, Dilt-XR, Diltia XT, Diltzac, Dilzem (UK), Disogram (UK), Gen-Diltiazem (CA), Med-Diltiazem (CA), Novo-Diltazem (CA), Nu-Diltiaz (CA), Optil (UK), Ratio-Diltiazem (CA), Sandoz Diltiazem (CA), Slozem (UK), Taztia XT, Tiazac, Tildiem (UK), Viazem (UK), Zemtard (UK)

Pharmacologic class: Calcium channel blocker

Therapeutic class: Antianginal, antiarrhythmic (class IV), antihypertensive

Pregnancy risk category C


Inhibits calcium from entering myocardial and vascular smooth-muscle cells, thereby depressing myocardial and smooth-muscle contraction and decreasing impulse formation and conduction velocity. As a result, systolic and diastolic pressures decrease.


Capsules (extended-release, sustained-release): 60 mg, 90 mg, 120 mg, 180 mg, 240 mg, 300 mg, 360 mg, 420 mg

Injection: 5 mg/ml in 10-ml vials, 100-mg Monovial

Tablets: 30 mg, 60 mg, 90 mg, 120 mg

Indications and dosages

Angina pectoris and vasospastic (Prinzmetal's) angina; hypertension; supraventricular tachyarrhythmias; atrial flutter or fibrillation

Adults: 30 to 90 mg P.O. three to four times daily (tablets), or 60 to 120 mg P.O. b.i.d. (sustained-release), or 180 to 240 mg P.O. once daily (extended-release), adjusted after 14 days as needed, up to a total daily dosage of 360 mg. Or 0.25 mg/kg by I.V. bolus over 2 minutes; if response is inadequate after 15 minutes, may give 0.35 mg/kg over 2 minutes; may follow with continuous I.V. infusion at 10 mg/hour (at a range of 5 to 15 mg/hour) for up to 24 hours.

Dosage adjustment

• Severe hepatic or renal impairment

• Elderly patients

Off-label uses

• Unstable angina, coronary artery bypass graft surgery

• Tardive dyskinesia

• Migraine

• Hyperthyroidism

• Raynaud's phenomenon


• Hypersensitivity to drug

• Atrial flutter or fibrillation associated with shortened refractory period (Wolff-Parkinson-White syndrome, with I.V. use)

• Recent myocardial infarction or pulmonary congestion

• Cardiogenic shock, concurrent I.V. beta-blocker therapy, ventricular tachycardia, neonates (with I.V. use, because of benzyl alcohol in syringe formulation)

• Sick sinus syndrome, second- or third-degree atrioventricular block (except in patients with ventricular pacemakers)

• Hypotension (systolic pressure below 90 mm Hg)


Use cautiously in:

• severe hepatic or renal impairment, heart failure

• history of serious ventricular arrhythmias

• concurrent use of I.V. diltiazem and I.V. beta blockers

• elderly patients

• pregnant or breastfeeding patients

• children (safety not established).


• When giving I.V., dilute in dextrose 5% in water or normal saline solution.

• Give I.V. bolus dose over 2 minutes; a second bolus may be given after 15 minutes.

• Administer continuous I.V. infusion at a rate of 5 to 15 mg/hour.

When giving by continuous I.V. infusion, make sure emergency equipment is available and that patient has continuous ECG monitoring with frequent blood pressure monitoring.

• Don't crush tablets or sustained-release capsules; they must be swallowed whole.

• Withhold dose if systolic blood pressure falls below 90 mm Hg, diastolic pressure is below 60 mm Hg, or apical pulse is slower than 60 beats/minute.

Adverse reactions

CNS: headache, abnormal dreams, anxiety, confusion, dizziness, drowsiness, nervousness, psychiatric disturbances, asthenia, paresthesia, syncope, tremor

CV: peripheral edema, bradycardia, chest pain, hypotension, palpitations, tachycardia, arrhythmias, heart failure

EENT: blurred vision, tinnitus, epistaxis

GI: nausea, vomiting, diarrhea, constipation, dyspepsia, dry mouth

GU: urinary frequency, dysuria, nocturia, polyuria, gynecomastia, sexual dysfunction

Hematologic: anemia, leukopenia, thrombocytopenia

Metabolic: hyperglycemia

Musculoskeletal: joint stiffness, muscle cramps

Respiratory: cough, dyspnea

Skin: rash, dermatitis, flushing, diaphoresis, photosensitivity, pruritus, urticaria, erythema multiforme

Other: unpleasant taste, gingival hyperplasia, weight gain, decreased appetite, Stevens-Johnson syndrome


Drug-drug. Beta-adrenergic blockers, digoxin, disopyramide, phenytoin: bradycardia, conduction defects, heart failure

Carbamazepine, cyclosporine, quinidine: decreased diltiazem metabolism, increased risk of toxicity

Cimetidine, ranitidine: increased blood level and effects of diltiazem

Fentanyl, nitrates, other antihypertensives, quinidine: additive hypotension

HMG-CoA reductase inhibitors, imipramine, sirolimus, tacrolimus: increased blood levels of these drugs

Lithium: decreased lithium blood level, reduced antimanic control

Nonsteroidal anti-inflammatory drugs: decreased antihypertensive effect of diltiazem

Theophylline: increased theophylline effects

Drug-diagnostic tests. Hepatic enzymes: increased levels

Drug-food. Grapefruit juice: increased blood level and effects of diltiazem

Drug-behaviors. Acute alcohol ingestion: additive hypotension

Patient monitoring

• Check blood pressure and ECG before starting therapy, and monitor closely during dosage adjustment period. Withhold dose if systolic pressure is below 90 mm Hg.

Monitor for signs and symptoms of heart failure and worsening arrhythmias.

• Supervise patient during ambulation.

Patient teaching

• Instruct patient to swallow extended-release capsules whole and not to crush or chew them.

• Advise patient to change position slowly to minimize light-headedness and dizziness.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and behaviors mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


(dil-tye-a-zem) ,


(trade name),

Cardizem CD

(trade name),

Cardizem LA

(trade name),

Cartia XT

(trade name),

Dilacor XR

(trade name),

Taztia XT

(trade name),


(trade name)


Therapeutic: antianginals
Pharmacologic: calcium channel blockers
Pregnancy Category: C


Hypertension.Angina pectoris and vasospastic (Prinzmetal’s) angina.Supraventricular tachyarrhythmias and rapid ventricular rates in atrial flutter or fibrillation.


Inhibits transport of calcium into myocardial and vascular smooth muscle cells, resulting in inhibition of excitation-contraction coupling and subsequent contraction.

Therapeutic effects

Systemic vasodilation resulting in decreased BP.
Coronary vasodilation resulting in decreased frequency and severity of attacks of angina.
Reduction of ventricular rate in atrial fibrillation or flutter.


Absorption: Well absorbed, but rapidly metabolized after oral administration.
Distribution: Unknown.
Protein Binding: 70–80%.
Metabolism and Excretion: Mostly metabolized by the liver (CYP3A4 enzyme system).
Half-life: 3.5–9 hr.

Time/action profile

PO30 min2–3 hr6–8 hr
PO–SRunknownunknown12 hr
PO–CD, XR, LAunknown14 days†up to 24 hr
IV2–5 min2–4 hrunknown
†Maximum antihypertensive effect with chronic therapy


Contraindicated in: Hypersensitivity;Sick sinus syndrome;2nd- or 3rd-degree AV block (unless an artificial pacemaker is in place);Systolic BP <90 mm Hg;Recent MI or pulmonary congestion;Concurrent use of rifampin.
Use Cautiously in: Severe hepatic impairment (↓ dose recommended); Geriatric: ↓ dose; slower IV infusion rate recommended; ↑ risk of hypotension; consider age-related decrease in body mass, ↓ hepatic/renal/cardiac function, concurrent drug therapy and other disease states);Severe renal impairment;Serious ventricular arrhythmias or HF; Obstetric / Lactation / Pediatric: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

  • abnormal dreams
  • anxiety
  • confusion
  • dizziness
  • drowsiness
  • headache
  • nervousness
  • psychiatric disturbances
  • weakness

Ear, Eye, Nose, Throat

  • blurred vision
  • disturbed equilibrium
  • epistaxis
  • tinnitus


  • cough
  • dyspnea


  • arrhythmias (life-threatening)
  • HF (life-threatening)
  • peripheral edema (most frequent)
  • bradycardia
  • chest pain
  • hypotension
  • palpitations
  • syncope
  • tachycardia


  • ↑ liver enzymes
  • anorexia
  • constipation
  • diarrhea
  • dry mouth
  • dysgeusia
  • dyspepsia
  • nausea
  • vomiting


  • dysuria
  • nocturia
  • polyuria
  • sexual dysfunction
  • urinary frequency


  • stevens-johnson syndrome (life-threatening)
  • dermatitis
  • erythema multiforme
  • flushing
  • sweating
  • photosensitivity
  • pruritus/urticaria
  • rash


  • gynecomastia
  • hyperglycemia


  • anemia
  • leukopenia
  • thrombocytopenia


  • weight gain


  • joint stiffness
  • muscle cramps


  • paresthesia
  • tremor


  • gingival hyperplasia


Drug-Drug interaction

↑ hypotension may occur when used with fentanyl, other antihypertensives, nitrates, acute ingestion of alcohol, or quinidine.Antihypertensive effects may be ↓ by NSAIDs.May ↑ digoxin levels.May ↑ levels of and risk of myopathy from simvastatin and lovastatin.Concurrent use with beta blockers, clonidine, digoxin, disopyramide, or phenytoin may result in bradycardia, conduction defects, or HF.Phenobarbital and phenytoin may ↑ metabolism and ↓ effectiveness.May ↓metabolism of and ↑ risk of toxicity from cyclosporine, quinidine, or carbamazepine.Cimetidine and ranitidine ↑ levels and effects.May ↑ or ↓ the effects of lithium or theophylline.Grapefruit juice ↑ levels and effect.


Oral (Adults) 30–120 mg 3–4 times daily or 60–120 mg twice daily as SR capsules or 180–240 mg once daily as CD or XR capsules or LA tablets (up to 360 mg/day); Concurrent simvastatin therapy—Diltiazem dose should not exceed 240 mg/day and simvastatin dose should not exceed 10 mg/day.
Intravenous (Adults) 0.25 mg/kg; may repeat in 15 min with a dose of 0.35 mg/kg. May follow with continuous infusion at 10 mg/hr (range 5–15 mg/hr) for up to 24 hr.

Availability (generic available)

Tablets: 30 mg, 60 mg, 90 mg, 120 mg Cost: Generic — 30 mg $10.44 / 100, 60 mg $22.25 / 100, 90 mg $26.89 / 100
Sustained-release capsules: 60 mg, 90 mg, 120 mg Cost: Generic — 60 mg $83.05 / 100, 90 mg $94.95 / 100, 120 mg $123.75 / 100
Extended-release capsules (Cardizem CD, Dilacor XR, Tiazac, Cartia XT, Taztia XT): 120 mg, 180 mg, 240 mg, 300 mg, 360 mg, 420 mg Cost: Generic — 180 mg $58.19 / 100, 240 mg $63.54 / 100, 420 mg $171.49 / 100
Extended-release tablets (Cardizem LA): 120 mg, 180 mg, 240 mg, 300 mg, 360 mg, 420 mg
Injection: 5 mg/mL

Nursing implications

Nursing assessment

  • Monitor BP and pulse prior to therapy, during dose titration, and periodically during therapy. Monitor ECG periodically during prolonged therapy. May cause prolonged PR interval.
    • Monitor intake and output ratios and daily weight. Assess for signs of HF (peripheral edema, rales/crackles, dyspnea, weight gain, jugular venous distention).
    • Monitor frequency of prescription refills to determine adherence.
    • Patients receiving digoxin concurrently with calcium channel blockers should have routine serum digoxin levels checked and be monitored for signs and symptoms of digoxin toxicity.
  • Assess for rash periodically during therapy. May cause Stevens-Johnson syndrome. Discontinue therapy if severe or if accompanied with fever, general malaise, fatigue, muscle or joint aches, blisters, oral lesions, conjunctivitis, hepatitis and/or eosinophilia.
  • Angina: Assess location, duration, intensity, and precipitating factors of patient’s anginal pain.
  • Arrhythmias: Monitor ECG continuously during administration. Report bradycardia or prolonged hypotension promptly. Emergency equipment and medication should be available. Monitor BP and pulse before and frequently during administration.
  • Lab Test Considerations: Total serum calcium concentrations are not affected by calcium channel blockers.
    • Monitor serum potassium periodically. Hypokalemia ↑ the risk of arrhythmias and should be corrected.
    • Monitor renal and hepatic functions periodically during long-term therapy. May cause ↑ in hepatic enzymes after several days of therapy, which return to normal on discontinuation of therapy.

Potential Nursing Diagnoses

Acute pain (Indications)
Decreased cardiac output (Adverse Reactions)


  • Do not confuse Tiazac (diltiazem) with Ziac (bisprolol/hydrochlorothiazide).
  • Oral: May be administered without regard to meals. May be administered with meals if GI irritation becomes a problem.
    • Do not open, crush, break, or chew sustained-release capsules or tablets. Empty tablets that appear in stool are not significant. Crush and mix diltiazem with food or fluids for patients having difficulty swallowing.
  • Intravenous Administration
  • Diluent: Administer bolus dose undiluted.Concentration: 5 mg/mL.
  • Rate: Administer over 2 min.
  • Continuous Infusion: Diluent: Dilute 125 mg in 100 mL, 250 mg in 250 mL, or 250 mg in 500 mL of 0.9% NaCl, D5W, or D5/0.45% NaCl. Infusion is stable for 24 hr at room temperature or if refrigerated.Concentration: 125 mg/125 mL (1 mg/mL), 250 mg/300 mL (0.83 mg/mL), 250 mg/550 mL (0.45 mg/mL).
  • Rate: See Route/Dosage section. Titrate to patient's heart rate and BP response.
  • Y-Site Compatibility: albumin, alemtuzumab, alfentanil, amifostine, amikacin, aminocaproic acid, amiodarone, amphotericin B colloidal, anidulafungin, argatroban, atracurium, azithromycin, aztreonam, bivalirudin, bleomycin, bumetanide, buprenorphine, busulfan, butorphanol, calcium chloride, calcium gluconate, carboplatin, carmustine, caspofungin, cefazolin, cefotaxime, cefotetan, cefoxitin, ceftaroline, ceftazidime, ceftriaxone, cefuroxime, chlorpromazine, ciprofloxacin, cisatracurium, cisplatin, clindamycin, cyclophosphamide, cyclosporine, cytarabine, dactinomycin, daptomycin, dexamethasone, dexmedetomidine, dexrazoxane, digoxin, diphenhydramine, dobutamine, docetaxel, dolasetron, dopamine, doripenem, doxacurium, doxorubicin hydrochloride, doxycycline, droperidol, enalaprilat, ephendrine, epinephrine, epirubicin, eptifibatide, ertapenem, erythromycin lactobionate, esmolol, etoposide, etoposide phosphate, famotidine, fenoldopam, fentanyl, fluconazole, fludarabine, foscarnet, fosphenytoin, gemcitabine, gentamicin, glycopyrrolate, granisetron, haloperidol, hetastarch, hydralazine, hydromorphone, idarubicin, ifosfamide, imipenem/cilastatin, irinotecan, isoproterenol, labetalol, leucovorin calcium, levofloxacin, lidocaine, linezolid, lorazepam, magnesium sulfate, mannitol, mechlorethamine, melphalan, meperidine, meropenem, metaraminol, methyldopate, metoclopramide, metoprolol, metronidazole, midazolam, milrinone, mitoxantrone, morphine, moxifloxacin, multivitamins, mycophenolate, nalbuphine, naloxone, nesiritide, nicardipine, nitroglycerin, nitroprusside, norepinephrine, octreotide, ondansetron, oxacillin, oxaliplatin, oxytocin, paclitaxel, palonosetron, pamidronate, pancuronium, pemetrexed, penicillin G potassium, pentamidine, phentolamine, phenylephrine, potassium acetate, potassium chloride, potassium phosphates, prochlorperazine, promethazine, propranolol, quinupristin/dalfopristin, ranitidine, remifentanil, rocuronium, sodium acetate, streptozocin, succinylcholine, sufentanil, tacrolimus, telavancin, teniposide, theophylline, thiotepa, ticarcillin/clavulanate, tigecycline, tirofiban, tobramycin, trimethoprim/sulfamethoxazole, vancomycin, vasopressin, vecuronium, verapamil, vinblastine, vincristine, vinorelbine, voriconazole, zidovudine, zoledronic acid
  • Y-Site Incompatibility: allopurinol, amphotericin B lipid complex, amphotericin B liposome, cefepime, chloramphenicol, dantrolene, diazepam, doxorubicin liposomal, fluorouracil, furosemide, ganciclovir, ketorolac, methotrexate, micafungin, pantroprazole, pentobarbital, phenobarbital, phenytoin, piperacillin/tazobactam, rifampin, thiopental

Patient/Family Teaching

  • Advise patient to take medication as directed at the same time each day, even if feeling well. Take missed doses as soon as possible unless almost time for next dose; do not double doses. May need to be discontinued gradually.
    • Advise patient to avoid large amounts (6–8 glasses of grapefruit juice/day) during therapy.
    • Instruct patient on correct technique for monitoring pulse. Instruct patient to contact health care professional if heart rate is <50 bpm.
    • Caution patient to change positions slowly to minimize orthostatic hypotension.
    • May cause drowsiness or dizziness. Advise patient to avoid driving or other activities requiring alertness until response to the medication is known.
    • Instruct patient on importance of maintaining good dental hygiene and seeing dentist frequently for teeth cleaning to prevent tenderness, bleeding, and gingival hyperplasia (gum enlargement).
    • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to avoid concurrent use of alcohol or OTC medications and herbal products, especially cold preparations, without consulting health care professional.
    • Advise patient to notify health care professional if rash, irregular heartbeats, dyspnea, swelling of hands and feet, pronounced dizziness, nausea, constipation, or hypotension occurs or if headache is severe or persistent.
    • Caution patient to wear protective clothing and use sunscreen to prevent photosensitivity reactions.
  • Angina: Instruct patient on concurrent nitrate or beta-blocker therapy to continue taking both medications as directed and to use SL nitroglycerin as needed for anginal attacks.
    • Advise patient to contact health care professional if chest pain does not improve, worsens after therapy, or occurs with diaphoresis; if shortness of breath occurs; or if severe, persistent headache occurs.
    • Caution patient to discuss exercise restrictions with health care professional before exertion.
  • Hypertension: Encourage patient to comply with other interventions for hypertension (weight reduction, low-sodium diet, smoking cessation, moderation of alcohol consumption, regular exercise, and stress management). Medication controls but does not cure hypertension.
    • Instruct patient and family in proper technique for monitoring BP. Advise patient to take BP weekly and to report significant changes to health care professional.

Evaluation/Desired Outcomes

  • Decrease in BP.
  • Decrease in frequency and severity of anginal attacks.
    • Decrease in need for nitrate therapy.
    • Increase in activity tolerance and sense of well-being.
  • Suppression and prevention of tachyarrhythmias.
Drug Guide, © 2015 Farlex and Partners


Diltiazem, see there.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
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Tiazac Capsules are indicated for the treatment of hypertension, used alone or in combination with other antihypertensive medications.
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Both of the aforementioned standards cases, Rambus and Unocal, are based, in part, on a monopolization theory, as are several patent abuse cases--Schering-Plough, Biovail (Tiazac), and Bristol-Myers Squibb.
(94) In Biovail (Tiazac) and Bristol-Myers Squibb, the agency took the position that the listing of a patent in FDA's Orange Book is not petitioning conduct, and therefore is not protected by Noerr.
International over the right to market generic versions of Prilosec (the largest-selling drug worldwide), Naprelan and Tiazac, respectively.
"More recently we announced our ANDA filings for Tiazac and Naprelan, both of which use our patent-pending controlled-release technology," Hahn says.