Drug Name
Generic Name : diltiazem hydrochloride
Brand Name: Apo-Diltiaz (CAN), Cardizem, Cardizem CD, Cardizem LA, Cardizem SR, Cartia XT, Dilacor XR, Diltia XT, Gen-Diltiazem (CAN), Gen-Diltizaem CD (CAN), Novo-Diltiazem (CAN), Novo-Diltiazem CD (CAN), Nu-Diltiaz (CAN), ratio-Diltiazem (CAN), Tiazac
Classification: Calcium channel blocker, Antianginal, Antihypertensive
Pregnancy Category C
Dosage & Route
- Evaluate patient carefully to determine the appropriate dose of this drug.
ADULTS
- Initially, 30 mg PO qid before meals and hs; gradually increase dosage at 1- to 2-day intervals to 180–360 mg PO in three to four divided doses.
Extended-release
- Cardizem CD and Cartia XT: 180–240 mg PO for hypertension; 120–180 mg daily PO for angina.
- Cardizem LA: 120–540 mg daily PO for hypertension; 180–360 mg/day PO for chronic, stable angina. May be given with nitroglycerine or nitrate therapy.
- Dilacor XR and Diltia XT: 180–240 mg daily PO as needed; up to 480 mg has been used.
- Tiazac: 120–240 mg daily PO for hypertension—once daily dose; 120–180 mg PO once daily for angina.
IV
- Direct IV bolus: 0.25 mg/kg (20 mg for the average patient); second bolus of 0.35 mg/kg.
- Continuous IV infusion: 5–10 mg/hr with increases up to 15 mg/hr; may be continued for up to 24 hr.
PEDIATRIC PATIENTS
- Safety and efficacy not established.
Therapeutic actions
- Diltiazem relaxes coronary vascular smooth muscles by inhibiting influx of calcium ions during depolarisation of the vascular smooth muscles and myocardium. It increases myocardial O2 delivery in patients with vasospastic angina and inhibits cardiac conduction, particularly at the SA and AV nodes.
Indications
- 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
- ER form: Essential hypertension
- Parenteral: Paroxysmal supraventricular tachycardia, atrial fibrillation, atrial flutter
Adverse effects
- Headache, ankle oedema, hypotension, dizziness, fatigue, flushing, nausea, GI discomfort, gingival hyperplasia, rashes, erythema multiforme, exfoliative dermatitis, photosensitivity, occasionally hepatitis.
- Potentially Fatal: AV block, bradycardia, asystole, sinus arrest.
Contraindications
- Sick-sinus syndrome; 2nd or 3rd ° AV block; porphyria. Severe congestive cardiac failure; marked bradycardia. Pregnancy and lactation.
Nursing considerations
Assessment
- History: Allergy to diltiazem, impaired hepatic or renal function, sick sinus syndrome, heart block, lactation, pregnancy
- Physical: Skin lesions, color, edema; P, BP, baseline ECG, peripheral perfusion, auscultation; R, adventitious sounds; liver evaluation, normal output; LFTs, renal function tests, urinalysis
Interventions
- Monitor patient carefully (BP, cardiac rhythm, and output) while drug is being titrated to therapeutic dose; dosage may be increased more rapidly in hospitalized patients under close supervision.
- Monitor BP carefully if patient is on concurrent doses of nitrates.
- Monitor cardiac rhythm regularly during stabilization of dosage and periodically during long-term therapy.
- Ensure patient swallows ER preparations whole; do not cut, crush, or chew.
Teaching points
- Swallow extended-release and long-acting preparations whole; do not cut, crush, or chew; do not drink grapefruit juice while using this drug.
- You may experience these side effects: Nausea, vomiting (eat frequent small meals); headache (regulate light, noise, and temperature; medicate if severe).
- Report irregular heart beat, shortness of breath, swelling of the hands or feet, pronounced dizziness, constipation.