Consumer medicine information

1. Why am I using Cardizem?

Cardizem CD capsules or Cardizem tablets both contain an active ingredient diltiazem hydrochloride. Cardizem tablets are used to prevent angina. Cardizem CD capsules are used to prevent angina or to treat hypertension (high blood pressure).
For more information, see Section 1. Why am I using Cardizem? in the full CMI.

2. What should I know before I use Cardizem?

Do not use if you have ever had an allergic reaction to Cardizem CD capsules or Cardizem tablets or any of the ingredients listed at the end of the CMI.
Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.
For more information, see Section 2. What should I know before I use Cardizem? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with Cardizem and affect how it works.
A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use Cardizem?

• Cardizem CD capsules can be taken once a day, preferably at the same time every day.

• Cardizem tablets can be taken three or four times a day.

• Swallow the capsules or the tablets with a glass of water. Do not chew them.

• Your doctor will tell you how often and how much Cardizem CD or Cardizem tablets to take.

5. What should I know while using Cardizem?

6. Are there any side effects?

All medicines can have side effects. Sometimes they are serious, but most of the time they are not. Tell your doctor or pharmacist as soon as possible if you do not feel well while you are using these medicines. Some of the serious side effects are heat beating irregularly, slowly or very quickly; continuously lightheaded or dizzy; feeling pain, which may be severe, in your left arm and chest. For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.

1 Name of Medicine

Cardizem CD (diltiazem hydrochloride) 180 mg modified release capsules.
Cardizem CD (diltiazem hydrochloride) 240 mg modified release capsules.
Cardizem CD (diltiazem hydrochloride) 360 mg modified release capsules.

2 Qualitative and Quantitative Composition

Cardizem CD capsules contain a blend of beads with controlled dissolution characteristics for once a day administration. The capsules are available as either 180 mg, 240 mg or 360 mg diltiazem hydrochloride in sustained release form.
Diltiazem hydrochloride is a white to off white crystalline powder with a bitter taste. It is freely soluble in water, methanol and chloroform.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Modified release capsule.
Cardizem CD is available in 3 strengths:
180 mg. Light turquoise blue/blue capsule.
240 mg. Blue/blue capsule.
360 mg. Light blue/white capsule.

4 Clinical Particulars

4.9 Overdose

The oral LD₅₀ in mice and rats ranged from 415 to 740 mg/kg and from 560 to 810 mg/kg, respectively. The intravenous LD₅₀ in these species was 60 and 38 mg/kg, respectively. The oral LD₅₀ in dogs is considered to be in excess of 50 mg/kg, while lethality was seen in monkeys at 360 mg/kg. The toxic dose in man is not known. Due to extensive metabolism, blood levels after a standard dose of diltiazem can vary over tenfold, limiting the usefulness of blood levels in overdose cases. There have been 29 cases of diltiazem overdose in doses ranging from less than 1 g to 10.8 g. Sixteen of these reports involved multiple drug ingestions. Twenty two reports indicated patients had recovered from diltiazem overdose ranging from less than 1 g to 10.8 g. There were seven reports with a fatal outcome; although the amount of diltiazem ingested was unknown, multiple drug ingestions were confirmed in six of the seven reports.
The clinical effects of acute overdose can involve pronounced hypotension possibly leading to collapse and acute kidney injury, sinus bradycardia with or without isorhythmic dissociation, sinus arrest, cardiac arrest, heart block, cardiac failure and atrioventricular conduction disturbances. Most reports of overdose described some supportive medical measure and/or drug treatment.
Bradycardia frequently responded favourably to atropine as did heart block, although cardiac pacing was also frequently utilised to treat heart block. Fluids and vasopressors were used to maintain blood pressure, and in cases of cardiac failure inotropic agents were administered. In addition, some patients received treatment with ventilatory support, gastric lavage, activated charcoal, and/or intravenous calcium. Evidence of the effectiveness of intravenous calcium administration to reverse the pharmacological effects of diltiazem overdose was conflicting.
Non-cardiogenic pulmonary oedema has rarely been reported as a consequence of diltiazem overdose that may manifest with a delayed onset (24-48 hours post-ingestion) and require ventilatory support. Early resuscitative measures (including fluid resuscitation) to maintain perfusion and cardiac output may be precipitating factors due to fluid overload.
In the event of overdose or exaggerated response, appropriate supportive measures should be employed in addition to gastrointestinal decontamination. Diltiazem does not appear to be removed by peritoneal or haemodialysis. Based on the known pharmacological effects of diltiazem and/or reported clinical experiences, the following measures may be considered.
Bradycardia. Administer atropine (0.60 to 1.0 mg). If there is no response to vagal blockade, administer isoprenaline cautiously.
High degree A-V block. Treat as for bradycardia above. Fixed high degree A-V block should be treated with cardiac pacing.
Cardiac failure. Administer inotropic agents (isoprenaline, dopamine or dobutamine) and diuretics.
Hypotension. Vasopressors (e.g. dopamine or noradrenaline acid tartrate).
Actual treatment and dosage should depend on the severity of the clinical situation and the judgement and experience of the treating physician.
Symptoms and signs of overdose may be delayed due to the controlled release properties of the product, so patients should be kept under observation for at least 24 hours.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.3 Preclinical Safety Data

Genotoxicity. No data available.
Carcinogenicity. No data available.

6 Pharmaceutical Particulars

6.7 Physicochemical Properties

Chemical structure. Diltiazem hydrochloride is a calcium ion influx inhibitor (slow channel blocker or calcium antagonist). Its molecular formula is C₂₂H₂₆N₂O₄S.HCl and it has the following structure:
https://stagingapi.mims.com/au/public/v2/images/fullchemgif/CSDILTIA.gif Chemically diltiazem hydrochloride is the hydrochloride salt of (2S,3S)-5-(2-dimethylaminoethyl)- 2,3,4,5-tetrahydro- 2-(4-methoxyphenyl)-4-oxo- 1,5-benzothiazepin-3-yl acetate. It has a molecular weight of 450.98.
CAS number. 33286-22-5.

7 Medicine Schedule (Poisons Standard)

Prescription Only Medicine (Schedule 4).

Summary Table of Changes

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