Diltiazem
Diltiazem is a calcium channel blocker used to treat high blood pressure, angina (chest pain), and certain heart rhythm disorders. It works by relaxing blood vessels and reducing the heart's workload, allowing blood to flow more easily. This medication is typically prescribed when lifestyle changes alone are insufficient to control cardiovascular conditions.
Diltiazem is a calcium channel blocker that treats high blood pressure, angina, and heart rhythm problems by relaxing blood vessels and reducing heart workload.
Key facts at a glance
- ATC
- C05AE03
- RxNorm
- 3443
- Generic
- Diltiazem
- Class
- atc-c05
- Brands
- Matzim, Tiadylt, Cardizem, Tiazac, Taztia, Cartia, Dilt, Diltzac
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- injection, capsule, tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 120-240mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 30-60mg 3-4 times daily
- Maximum
- consult physician
- Frequency
- every 6-8 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 0.25mg/kg bolus over 2 minutes
- Maximum
- consult physician
- Frequency
- single dose, may repeat 0.35mg/kg
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
9 groupspregnancy
first trimesteravoid if possible
use only if benefits outweigh potential risks to fetus
regular fetal monitoring and ultrasound assessments
Use with caution and monitor for adverse effects.
pregnancy
second third trimesteruse lowest effective dose
monitor for fetal growth and well-being
regular fetal monitoring, growth assessments
Use with caution and monitor for adverse effects.
lactation
breastfeedingmonitor infant closely
consider alternative or discontinue breastfeeding
observe infant for hypotension, bradycardia, feeding problems
Use with caution and monitor for adverse effects.
geriatric
elderly 65start with lower dose, titrate slowly
increased sensitivity to drug effects, monitor for hypotension
regular blood pressure and heart rate monitoring
Use with caution and monitor for adverse effects.
pediatric_age
children under 12not recommended for use
avoid use in pediatric population unless specifically prescribed
not established for pediatric use
Use of this medication in this population requires careful consideration of risks and benefits.
renal_impairment
mild moderateno major adjustment needed, monitor closely
use with caution, monitor renal function
monitor renal function and blood pressure regularly
Use with caution and monitor for adverse effects.
renal_impairment
severereduce dose, extended interval consideration
use with extreme caution, dose reduction recommended
frequent monitoring of renal function and drug levels
Use with caution and monitor for adverse effects.
hepatic_impairment
mild moderateuse with caution, consider dose reduction
diltiazem is metabolized in liver, monitor closely
regular liver function tests and blood pressure monitoring
Use with caution and monitor for adverse effects.
hepatic_impairment
severesignificant dose reduction recommended
use only if necessary with close monitoring
frequent monitoring of liver function and clinical status
Use with caution and monitor for adverse effects.
Statistics and clinical data
Commonly prescribed since
FDA approved diltiazem in 1982 for cardiovascular indications
Drug class
ATC code C08CA01 - Non-dihydropyridine calcium channel blocker
Common uses
Primary therapeutic indications for diltiazem
Mechanism of action
Blocks calcium influx into vascular smooth muscle and cardiac myocytes
Diltiazem is used to treat hypertension (high blood pressure), chronic stable angina, and certain types of abnormal heart rhythms such as supraventricular tachycardias. It may be used alone or with other blood pressure medications.
Diltiazem blocks calcium from entering smooth muscle cells lining blood vessels and the heart. This causes blood vessels to relax and widen (vasodilation), reduces the force of heart contractions, and slows electrical conduction through the heart, all of which decrease blood pressure and oxygen demand.
May cause dizziness or fatigue; avoid grapefruit juice as it can increase drug levels. Use cautiously in patients with heart failure or conduction abnormalities. Do not stop taking suddenly without medical guidance. Inform your doctor about all medications, as diltiazem can interact with many drugs including beta-blockers, digoxin, and statins.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 24, 2026. · Read our editorial policy