This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo

Diltiazem 8 hour modified release preparations

Updated 2 Feb 2023 | Calcium channel blockers


8 hour modified release oral formulations containing diltiazem hydrochloride.

Drugs List

  • diltiazem 60mg 8 hour modified release tablets
  • RETALZEM 60mg modified release tablet
  • TILDIEM 60mg modified release tablet
  • Therapeutic Indications


    Hypertension - mild to moderate
    Prophylaxis of angina pectoris
    Treatment of angina pectoris

    Unlicensed Uses

    Atrial fibrillation
    Atrial flutter
    Raynaud's syndrome



    60mg three times daily.

    If necessary, the dose may be increased up to 360mg daily. Doses of up to 480mg daily have been used with benefit in some patients, especially in cases of unstable angina.


    Plasma levels of diltiazem can be increased in elderly patients.

    The recommended starting dose is 60mg twice daily. The heart rate should be monitored regularly and the dose should not be increased if heart rate falls below 50 beats per minute.


    Raynaud's syndrome
    Children aged 12 to 18 years (unlicensed)
    30mg to 60mg, given two to three times a day.

    Patients with Renal Impairment

    Plasma levels of diltiazem can be increased in patients with renal impairment.

    In patients with renal impairment, the recommended starting dose is 60mg twice daily. The heart rate should be monitored regularly and the dose should not be increased if heart rate falls below 50 beats per minute.

    Patients with Hepatic Impairment

    Plasma levels of diltiazem can be increased in patients with hepatic impairment.

    In patients with hepatic impairment, the recommended starting dose is 60mg twice daily. The heart rate should be monitored regularly and the dose should not be increased if heart rate falls below 50 beats per minute.


    Children under 12 years
    Systolic blood pressure < 90mmHg
    Bradycardia with pulse rate at rest < 50 beats per minute
    Cardiogenic shock
    Congestive cardiac failure
    Left ventricular failure with stasis
    Non paced second/third degree AV block
    Non-paced sinus node dysfunction
    Severe aortic stenosis

    Precautions and Warnings

    Children aged 12 to 18 years
    Females of childbearing potential
    Predisposition to gastrointestinal obstruction
    Bronchial hyperreactivity
    Diabetes mellitus
    First degree atrioventricular block
    Glucose-galactose malabsorption syndrome
    Hepatic impairment
    Lactose intolerance
    Reduced left ventricular function
    Renal impairment
    Severe hypotension

    Anaesthetist should be made aware patient is taking this medication
    Avoid concurrent use of beta blockers in patients with conduction defects
    May exacerbate asthma
    Reduce dose in patients with hepatic impairment
    Reduce dose in patients with renal impairment
    Advise ability to drive/operate machinery may be affected by side effects
    Not all available brands are licensed for all indications
    Contains lactose
    Exclude pregnancy prior to initiation of treatment
    Monitor antidiabetic drug treatment
    Monitor heart rate pre-treatment and periodically thereafter
    Monitor patients with existing or tendency towards diabetes mellitus
    Monitor respiratory function
    Advise patient to report any new or worsening respiratory symptoms
    Consider discontinuing if depression develops
    May cause bronchospasm
    Patient should be made aware of possible adverse effects on mood/behaviour
    Abrupt withdrawal may be associated with exacerbation of angina
    Reduce dose in elderly
    Advise patient grapefruit products may increase plasma level
    Female: Ensure adequate contraception during treatment
    Advise patients that empty tablet/capsule may be observed in stools

    Calcium channel blockers do not reduce the risk of myocardial infarction in unstable angina. The use of diltiazem should be reversed for patients resistant to treatment with beta-blockers. However, because of the risk of bradycardia, diltiazem should be used with caution in association with beta-blockers. Avoid concurrent use of beta blockers with diltiazem in patients with pre-existing conduction defects.

    Acute renal failure secondary to decreased renal perfusion has been reported in patients with reduced left ventricular function, severe bradycardia or severe hypotension.

    Pregnancy and Lactation


    Diltiazem is contraindicated during pregnancy.

    The limited available data on the use of diltiazem in pregnant patients suggests that reproductive risk is low. Diltiazem has resulted in reproductive toxicity in some animal species (rat, mice and rabbit) (Briggs, 2015).

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Use diltiazem with caution during breastfeeding.

    Diltiazem is excreted in human breast milk with approximately equal concentration in maternal serum and the breast milk (Briggs, 2015). The quantities ingested by the infant are likely to be small and LactMed considers the quantity unlikely to be problematic.

    Schaefer (2015) considers diltiazem to be one of the calcium channel blockers of choice for hypertension while breastfeeding.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Abdominal pain
    Acute generalised exanthematous pustulosis
    Acute renal failure
    Aggravation of existing asthma
    Angioneurotic oedema
    Atrioventricular block
    Bundle branch block
    Cardiac arrest
    Congestive cardiac failure
    Desquamative erythema
    Dry mouth
    Erythema multiforme
    Exfoliative dermatitis
    Extrapyramidal effects
    Gastric pain
    Gastro-intestinal symptoms
    Gingival hyperplasia
    Increase in alkaline phosphatase
    Increase in lactate dehydrogenase
    Increase in serum ALT/AST
    Leukocytoclastic vasculitis
    Lichenoid keratosis
    Mood changes
    Orthostatic hypotension
    Peripheral oedema
    Sino-atrial block
    Stevens-Johnson syndrome
    Toxic epidermal necrolysis


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: December 2016

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

    Summary of Product Characteristics: Diltiazem Hydrochloride Tablets 60mg. Actavis UK Ltd. Revised April 2016.

    Summary of Product Characteristics: Retalzem 60mg MR Tablets. Kent Pharmaceuticals Ltd. Revised June 2014.

    Summary of Product Characteristics: Tildiem 60mg Modified-Release tablets. Sanofi. Revised May 2020.

    NAPOS: The Norwegian Porphyria Centre
    Available at:
    Drug: Diltiazem. Last accessed: December, 2016

    NICE Evidence Services Available at: Last accessed: 22 August 2017

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Diltiazem. Last revised: March 10, 2015
    Last accessed: December 7, 2016

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.