Zemtard® XL (diltiazem hydrochloride)

Zemtard XL (diltiazem hydrochloride) Prescribing Information
Please refer to the Summary of Product Characteristics (SmPC) before prescribing Zemtard XL.

Presentation: Hard gelatin capsules containing prolonged release diltiazem hydrochloride beads for oral use. Zemtard 120 XL: Brownish-red and orange capsules marked “DIL 120”, each containing 120mg diltiazem hydrochloride. Zemtard 180 XL: Pink and grey capsules marked “DIL 180”, each containing 180mg diltiazem hydrochloride. Zemtard 240 XL: Light blue capsules marked “DIL 240”, each containing 240mg diltiazem hydrochloride. Zemtard 300 XL: Light blue and white capsules marked “DIL 300”, each containing 300mg diltiazem hydrochloride. Indications: Treatment of mild to moderate hypertension. Prophylaxis and treatment of angina pectoris. Dosage and administration: Capsules should not be crushed or chewed but swallowed whole with half a glass of fluid, ideally before or during a meal. Zemtard is a prolonged-release product for once daily dosing. The dosage requirements may differ in patients with angina or hypertension. Zemtard is available in a range of strengths to enable dosage to be adjusted to meet the individual requirements of the patient. Careful titration of the dose should be considered where appropriate, as individual patient response may vary. To ensure consistency of response once established, particularly in prolonged-release formulations, Zemtard should be prescribed by brand name. Adults: The recommended dose is between 180 and 300mg given once daily. Doses of up to 360mg/day in hypertension and 480mg/day in angina may be of benefit in some patients. Elderly and patients with impaired renal or hepatic function: Recommended starting dose of 120mg daily. Heart rate should be monitored and if it falls below 50 beats per minute (bpm) the dose should not be increased. Plasma levels of diltiazem can be increased in this group of patients. Children: Not recommended. Contraindications: Hypersensitivity to diltiazem or any of the excipients; severe bradycardia (below 40 bpm); in sick sinus syndrome or in second- or third-degree AV block, in patients without a functioning ventricular pacemaker; in left ventricular failure with pulmonary congestion; diltiazem should not be given concomitantly with dantrolene infusion, lomitapide; in combination with ivabradine; pregnancy; in women of childbearing potential not using effective contraception and while breast-feeding. Warnings and precautions: Close observation is necessary in patients with heart failure or reduced left ventricular function, bradycardia (risk of exacerbation), or with first-degree AV block or prolonged PR interval detected on the electrocardiogram (ECG) (risk of exacerbation and rarely, of complete block). Cases of acute renal failure secondary to decreased renal perfusion have been reported in patients with existing cardiac disease especially reduced left ventricular function, severe bradycardia or severe hypotension. Careful monitoring of renal function is advised. Prior to general anaesthesia, the anaesthetist must be informed of ongoing diltiazem treatment. Depression of cardiac contractility, conductivity and automaticity, as well as vascular dilatation associated with anaesthetics may be potentiated by calcium channel blockers. Increase of plasma concentrations of diltiazem may be observed in the elderly and in patients with renal or hepatic insufficiency. The contraindications and precautions should be closely observed and close monitoring, particularly of heart rate, should be carried out at the beginning of treatment. Treatment with diltiazem may be associated with mood changes, including depression. Early recognition of relevant symptoms is important, especially in predisposed patients (drug discontinuation should be considered). Use with caution in patients at risk of developing an intestinal obstruction. Careful monitoring is necessary in patients with latent or manifest diabetes mellitus due to a possible increase in blood glucose. The use of diltiazem may induce bronchospasm, including asthma aggravation, especially in patients with preexisting bronchial hyper-reactivity. Cases have also been reported after dose increase. Patients should be monitored for signs and symptoms of respiratory impairment during diltiazem therapy. Patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine. Interactions: Concomitant use contraindicated for safety reasons: Dantrolene (infusion), ivabradine, lomitapide. Concomitant use requiring caution: Lithium, nitrate derivatives (prescription of nitrate derivatives should only be carried out at gradually increasing doses), theophylline, alpha-antagonists (combination should be considered only with strict monitoring of blood pressure), amiodarone and digoxin (particularly in elderly and with high doses), beta-blockers (combination must only be used under close clinical and ECG monitoring, particularly at the beginning of treatment), other antiarrhythmic agents (concomitant use is not recommended, combination should only be used under close clinical and ECG monitoring), carbamazepine (plasma carbamazepine concentrations should be assayed and dose adjusted if necessary), phenytoin (it is recommended that the phenytoin plasma concentrations be monitored), rifampicin (patient should be carefully monitored when initiating or discontinuing rifampicin treatment), cimetidine and ranitidine (patients currently receiving diltiazem therapy should be carefully monitored when initiating or discontinuing therapy with anti-H₂ agents, an adjustment in diltiazem daily dose may be necessary); immunosuppressants: ciclosporin (it is recommended that the ciclosporin dose be reduced, renal function monitored, circulating ciclosporin levels assayed and that the dose should be adjusted during combined therapy and after its discontinuation), sirolimus, tacrolimus and everolimus; atazanavir (reduce dose of diltiazem), ritonavir; barbiturates; X-ray contrast media; antiplatelet drugs. Combinations to be taken into account: Diltiazem is metabolised by CYP3A4. A moderate increase of diltiazem plasma concentration in co-administration with a stronger CYP3A4 inhibitor has been documented. Grapefruit juice may increase diltiazem exposure (1.2-fold). Patients who consume grapefruit juice should be monitored for increased adverse effects of diltiazem. Grapefruit juice should be avoided if an interaction is suspected. Diltiazem is also a CYP3A4 inhibitor. Co-administration with other CYP3A4 substrates may result in an increase in plasma concentration of either drug. Co-administration of diltiazem with a CYP3A4 inducer may result in a decrease of diltiazem plasma concentrations. Midazolam, triazolam (special care should be taken when prescribing short-acting benzodiazepines metabolised by CYP3A4 in patients using diltiazem); corticosteroids (patient should be monitored when initiating methylprednisolone treatment, adjustment of methylprednisolone dose may be necessary); statins  (e.g. atorvastatin, fluvastatin and simvastatin): an adjustment of the dose of statin may be necessary (see also product information of the relevant statin), when possible, it is recommended to use a statin not metabolised by CYP3A4 (e.g. pravastatin) with diltiazem; cilostazol; imipramine and possibly other tricyclic antidepressants, MAOIs; itraconazole; mefloquine. General information to be taken into account: Caution and careful titration are necessary in patients receiving diltiazem concomitantly with other agents known to affect cardiac contractility and/or conduction. Refer to SmPC for full details on interactions. Fertility, pregnancy and lactation: Diltiazem has been shown to have reproductive toxicity in certain animal species (rat, mice, rabbit). Diltiazem should not be used in pregnancy or in women of child-bearing potential not using effective contraception. As diltiazem is excreted in breast milk, breastfeeding whilst taking diltiazem is contraindicated. Effects on ability to drive and use machines: On the basis of reported adverse drug reactions, i.e. dizziness and malaise, the ability to drive and use machines could be altered. However, no studies have been performed. Undesirable effects: Very common (≥1/10): Peripheral oedema; Common (≥1/100 to <1/10): Headache, dizziness, atrioventricular block (may be of first, second or third degree; bundle branch block may occur), palpitations, flushing, constipation, dyspepsia, gastric pain, nausea, erythema, malaise; Uncommon (≥1/1,000 to ≤1/100): Nervousness, insomnia, bradycardia, orthostatic hypotension, anorexia, vomiting, diarrhoea, taste disturbance, weight gain, hepatic enzymes increase (AST, ALT, LDH, ALP); Rare (≥1/10,000 to ≤1/1,000): Dry mouth, urticaria; Not known (cannot be estimated from the available data): Thrombocytopenia, mood changes (including depression), extrapyramidal syndrome, bronchospasm (including asthma aggravation), sinoatrial block, congestive heart failure, sinus arrest, cardiac arrest (asystole), vasculitis (including leukocytoclastic vasculitis), gingival hyperplasia, hyperglycemia, hepatitis, photosensitivity (including lichenoid keratosis at sun exposed skin areas), angioneurotic oedema, rash, erythema multiforme (including Stevens-Johnson syndrome and toxic epidermal necrolysis), sweating, exfoliative dermatitis, acute generalised exanthematous pustulosis (AGEP), occasionally desquamative erythema with or without fever, lupus-like syndrome, gynecomastia, fatigue. Overdose: Please refer to SmPC. Basic NHS cost: Blister packs of 28 capsules. Zemtard 120mg XL: £6.10. Zemtard 180mg XL: £6.20. Zemtard 240 XL: £6.30. Zemtard 300 XL: £6.70. Legal classification: POM. MA Number:  Zemtard 120 XL: PL 27827/0033. Zemtard 180 XL: PL 27827/0034. Zemtard 240 XL: PL 27827/0035. Zemtard 300 XL: PL 27827/0036. Full prescribing information available from the MA Holder: Galen Limited, Seagoe Industrial Estate, Craigavon, Northern Ireland, BT63 5UA. Date of Preparation: July 2023.