Diltiazem
Calcium Antagonist · Calcium antagonist
Indications
Angina, hypertension.
Dosage
Adults: Usually 60 mg three times daily, increasing if necessary to max 480 mg daily in divided doses. Elderly: Initially 60 mg twice daily. Max: 360 mg daily. Children: Not recommended.
Adverse Effects
Bradycardia, 1st degree AV block, ankle oedema, nausea, headache, rash, flushing, hypotension, GI upset, fatigue, gingival hyperplasia. Changes in liver function, hepatitis, palpitations, dizziness, malaise, asthaenia, erythema, pruritus, hyperglycaemia. Mood changes incl depression.
Risk Factor (Pregnancy/Lactation)
Pregnancy: Contraindicated in pregnancy. Lactation: Contraindicated or not recommended. Contraindications: Sick sinus syndrome; 2nd or 3rd degree AV block; uncontrolled cardiac failure, left ventricular failure with pulmonary stasis, marked bradycardia, CHF. Precautions: Observe patients with mild bradycardia, 1st degree AV block or a prolonged PR interval. Acute porphyria. Hepatic impairment; monitor liver function periodically. Renal impairment, reduced left ventricular function, risk factors for intestinal obstruction, diabetes. Risk of bronchospasm; monitor for respiratory impairment. Elderly; monitor heart rate.
Interactions
Other antihypertensives, cardiac depressants, beta-blockers, digitalis, carbamazepine, cyclosporin, theophylline, H2 antagonists, dantrolene infusion, other CYP3A4 substrates, amiodarone, other antiarrhythmics, antiplatelets, rifampicin, digoxin, carbamazepine, phenytoin, phenobarbital, cilostazol, ritonavir, atazanavir, ivabradine, lithium, immunosuppressants, erythromycin, statins, benzodiazepines, methylprednisolone, anaesthetics, nitrates, TCADs, grapefruit juice.
Advice to Patient
Take with or without meals. Do not chew or crush extended release forms, swallow whole. Do not stop taking medication abruptly, gradually decrease the dose then stop. Contact prescriber if there is dizziness, chest pain, palpitations, irregular heartbeat, unusual cough, difficulty in breathing, swelling of extremities, muscle weakness, muscle tremors, confusion, or skin rash. Avoid alcohol and caffeine during therapy. Check blood pressure and pulse rate regularly. Maintain good oral hygiene, perform gum massage and visit a dentist every 6 months.
Pharmacokinetics
Onset of action: Oral: Immediate release tab: 30-60 min. IV: Bolus: 3 min. Duration: IV: Bolus: 1-3 hrs. Continuous infusion (after discontinuation): 0.5-10 hrs. Absorption: Immediate release tab: Approx. 98%. Extended release cap: Approx. 93%->95%. Metabolism: Hepatic (extensive first-pass effect). Bioavailability: Oral: Approx. 40%. Half-life elimination: Immediate release tab: 3-4.5 hrs. Extended release tab: 6-9 hrs. Extended release cap: 4-9.5 hrs. IV: Single dose: Approx. 3.4 hrs. Continuous infusion: 4-5 hrs. Time to peak, serum: Immediate release tab: 2-4 hrs. Extended release tab: 11-18 hrs. Extended release cap: 10-14 hrs. Excretion: Urine. Faeces.
Unlicensed Use
Children: Raynaud’s syndrome: ORAL:12-18 yr, 30-60 mg 2-3 times daily.
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
Always consult a pharmacist or doctor.