dilTIAZem (dil-tye-a-zem) Cardizem, Cardizem CD, Cardizem LA, Cartia XT, Taztia XT, Tiazac, Tiazac XC

 Indications

Hypertension. Angina pectoris and vasospastic (Prinzmetal’s)

angina. Supraventricular tachyarrhythmias and

rapid ventricular rates in atrial flutter or fibrillation.

Action

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.

Pharmacokinetics

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

ROUTE ONSET PEAK DURATION

PO 30 min 2–3 hr 6–8 hr

PO–CD, LA,

XT

unknown 14 days† up to 24 hr

IV 2–5 min 2–4 hr unknown

†Maximum antihypertensive effect with chronic therapy.

Contraindications/Precautions

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 (p

dose recommended); Geri:pdose; slower IV infusion

rate recommended;qrisk of hypotension; consider

age-related decrease in body mass,phepatic/renal/

cardiac function, concurrent drug therapy and other

disease states); Severe renal impairment; Serious ventricular

arrhythmias or HF; OB, Lactation, Pedi: Safety

not established.

Adverse Reactions/Side Effects

CNS: abnormal dreams, anxiety, confusion, dizziness,

drowsiness, headache, nervousness, psychiatric disturbances,

weakness. EENT: blurred vision, disturbed

equilibrium, epistaxis, tinnitus. Resp: cough, dyspnea.

CV: ARRHYTHMIAS, HF, peripheral edema, bradycardia,

chest pain, hypotension, palpitations, syncope, tachycardia.

GI:qliver enzymes, anorexia, constipation, diarrhea,

dry mouth, dysgeusia, dyspepsia, nausea, vomiting.

GU: dysuria, nocturia, polyuria, sexual

dysfunction, urinary frequency. Derm: STEVENS-JOHNSON

SYNDROME, dermatitis, erythema multiforme, flushing,

sweating, photosensitivity, pruritus/urticaria, rash.

Endo: gynecomastia, hyperglycemia. Hemat: anemia,

leukopenia, thrombocytopenia.Metab: weight

gain. MS: joint stiffness, muscle cramps. Neuro: paresthesia,

tremor. Misc: gingival hyperplasia.

Interactions

Drug-Drug:qhypotension may occur when used

with fentanyl, other antihypertensives, nitrates,

acute ingestion of alcohol, or quinidine. Antihypertensive

effects may bepby NSAIDs. Mayqdigoxin

levels. Mayqlevels of and risk of myopathy from simvastatin

and lovastatin. Concurrent use with beta

blockers, clonidine, digoxin, disopyramide, ivabradine,

or phenytoin may result in bradycardia,

conduction defects, or HF; avoid concurrent use with

ivabradine. Phenobarbital and phenytoin mayqmetabolism

andpeffectiveness. Maypmetabolism of and

qrisk of toxicity from cyclosporine, quinidine, or

carbamazepine. Cimetidine and ranitidineqlevels

and effects. Mayqorpthe effects of lithium or theophylline.

Drug-Food: Grapefruit juiceqlevels and effect.

Route/Dosage

PO (Adults): 30–120 mg 3–4 times daily 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.

IV (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. Extended-release capsules (Cardizem

CD, 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. Solution for injection: 5 mg/mL.