Dilcor

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Dilcor

Understanding Dilcor

Dilcor is a medication belonging to the class of drugs known as calcium channel blockers. It contains the active ingredient diltiazem hydrochloride, which is utilized primarily to manage certain conditions affecting the heart and blood vessels.

Mechanism of Action

Dilcor works by affecting the movement of calcium into the cells of the heart and blood vessels. Calcium is essential for the contraction of muscular tissues; by blocking these channels, the medication facilitates several physiological changes:

  • Vasodilation: It relaxes the smooth muscles in the walls of the arteries, allowing blood vessels to widen. This reduces the resistance against which the heart must pump.
  • Heart Rate Regulation: It slows the electrical conduction within the heart, which can help in managing specific types of irregular heart rhythms.
  • Reduced Workload: By relaxing the vessels and modulating the heart rate, the medication reduces the overall oxygen demand of the heart muscle.

Clinical Applications

This medication is typically prescribed for the management of chronic cardiovascular issues. Its primary uses include:

  1. Hypertension: It is used to help manage high blood pressure. Maintaining blood pressure within a standard range is vital for reducing the risk of long-term complications such as strokes or heart dysfunction.
  2. Angina Pectoris: Dilcor is used to prevent chronic chest pain caused by reduced blood flow to the heart muscle. It is important to note that it is intended for the long-term prevention of pain rather than the immediate relief of an acute attack.
  3. Heart Rhythm Management: In certain cases, it may be used to control the heart rate in patients with specific atrial arrhythmias.

As a systemic treatment, Dilcor is designed to provide stable, long-term management of these conditions rather than providing temporary symptomatic relief.

Regulatory References

  1. MedlinePlus Drug Information

What side effects are possible with Dilcor?

Possible Side Effects and Safety Information for Dilcor

Dilcor (diltiazem hydrochloride) may be associated with various adverse effects, ranging from common to rare but serious. The officially documented adverse reactions primarily involve the cardiovascular, nervous, and gastrointestinal systems, as well as the skin.

Adverse Reactions Overview

Classification Common Adverse Reactions (e.g., ge 1% incidence)
Cardiovascular Peripheral edema (swelling), flushing, bradycardia (slow heart rate), palpitations.
Nervous System Headache, dizziness, asthenia (weakness).
Gastrointestinal Constipation, nausea, dyspepsia.
Other Rash, fever, fatigue.

Serious and Clinically Significant Adverse Reactions

Severe adverse reactions, though infrequent, have been documented, including:

  • Cardiac Conduction Abnormalities: Second- or third-degree atrioventricular (AV) block, which may lead to dangerously slow heart rates, especially in patients with pre-existing heart conditions like sick sinus syndrome. Concomitant use with other drugs that slow cardiac conduction (e.g., beta-blockers) can increase this risk.
  • Hypotension: Marked decreases in blood pressure, potentially leading to symptomatic hypotension or fainting.
  • Hepatic Injury: Rare instances of significant elevations in liver enzymes consistent with acute hepatic injury, typically reversible upon discontinuation.
  • Severe Skin Reactions: Serious dermatological reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), have been reported.
  • Congestive Heart Failure: Worsening of pre-existing congestive heart failure has been observed due to the drug’s negative inotropic properties.

Safety Restrictions and Monitoring

Dilcor is contraindicated in patients with sick sinus syndrome or second-/third-degree AV block (unless a functioning ventricular pacemaker is present), in those with hypotension (e.g., systolic blood pressure <90 mmHg), or in patients with acute myocardial infarction complicated by pulmonary congestion. Caution and careful monitoring of cardiac function, renal function, and hepatic function are required, particularly in elderly patients or those with pre-existing organ impairment. The potential for acute hepatic injury requires monitoring of liver enzymes at regular intervals.

Overdose and Emergency Response

Overdose Scope

Property Official Regulatory Statement
Documented Overdose Presentations Symptoms include hypotension (low blood pressure), reflex tachycardia, dizziness, flushing, nausea, and disturbances in cardiac conduction like sinus node dysfunction or atrioventricular node dysfunction.
Physiological Systems Affected Cardiovascular system (Profound Hypotension, Bradycardia, Conduction Disturbances); Central Nervous System (Loss of Consciousness, Confusion).
Emergency-response statements Seek medical help right away for a suspected overdose. Call 911 (Emergency Services) or equivalent local emergency number, and Contact a Poison Control center.
Population-specific Overdose Notes Effects may be increased in patients with Liver Impairment due to the drug's prolonged clearance (slower removal from the body).

Overdose Classifications (High-level)

Property Official Regulatory Statement
Severity classification Overdose may be associated with life-threatening outcomes, specifically profound hypotension and cardiac arrest.
Overdose-context constraints No specific antidote is known; management is based on symptomatic and supportive treatment.

Resulting Overdose Structure

Official overdose statements:

  • Documented management includes monitoring cardiovascular and respiratory function, administration of fluids, vasopressors, and the judicious use of calcium infusion.
  • Hospital observation of up to 12 hours is required for asymptomatic patients who have ingested the extended-release formulation.
  • Activated charcoal or gastric lavage may be considered within one hour of a potentially toxic ingestion.
  • Dialysis is documented as not likely to be of any benefit due to the drug’s high protein binding.

Connection to the overall overdose profile: Regulatory documents define the overdose profile by highlighting the primary risk of severe cardiovascular instability, which mandates immediate intervention via emergency services. Since no specific antidote is available, management is focused on supportive procedures and requires a prolonged period of hospital monitoring due to the sustained-release nature of the tablet.

Therapeutic Uses of Dilcor

Dilcor (Nifedipine extended-release) is a prescription medication primarily used in situations that involve symptoms related to physical discomfort and noticeable physiological strain arising from chronic vascular conditions. The medication is commonly used to help with conditions related to elevated blood pressure and chest pain.

Sustained Management of High Blood Pressure

The medication is applied in addressing essential hypertension, supporting the sustained control of elevated blood pressure that creates noticeable physiological strain over time. The primary benefit is supportive cardiovascular protection, and it may assist with reducing the risk of major complications, including serious cardiovascular events, that arise from chronic high vascular resistance.

Control of Recurring Symptom Clusters

Dilcor is relevant for easing symptoms of both chronic stable angina and vasospastic angina, and is commonly used to help with conditions involving ischemic chest discomfort. It also is applied in addressing conditions like Raynaud's phenomenon, which involves episodic peripheral vasospasm in the extremities. It provides support that helps ease the overall symptom burden and assists with maintaining functional stability when symptoms interfere with routine activities.


Quick Fact: Management of Vascular Strain Symptoms This medication is often used for the long-term management of chronic conditions, supporting the sustained control of elevated systemic blood pressure.

Regulatory References

  1. NIH MedlinePlus overview on Nifedipine

Eligibility and Restrictions for Use

Eligibility for Using Dilcor (Nifedipine Extended-Release)

The official regulatory profile defines patient eligibility based on age, existing medical conditions, and physiological status. Dilcor is established for use in adult patients for its approved cardiovascular indications. Pediatric use (children and adolescents under 18 years) is not recommended because safety and efficacy data have not been established in this age group.


Contraindicated and Restricted Populations

Absolute contraindications mean the medicine must not be used in certain patient groups, as listed in the official prescribing information:

  • Patients with a known hypersensitivity to nifedipine or related dihydropyridines.
  • Individuals in a state of cardiogenic shock or those with unstable angina pectoris.
  • Patients during or within the first four weeks following an acute myocardial infarction.
  • Those receiving concomitant treatment with Rifampicin.

Use is restricted or conditional for other groups. Patients with impaired liver function require caution and close monitoring. Pregnancy is often contraindicated by European regulatory bodies, while US information requires that the potential benefit must outweigh any potential risk to the fetus. Use during breastfeeding is not recommended as the substance passes into human milk.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Dilcor, which contains Nifedipine, has a documented interaction profile primarily based on its metabolism via the CYP3A4 enzyme system and its pharmacodynamic effects. Official regulatory information provides specific guidance on co-administration with other substances.

Contraindicated and Restricted Combinations

Co-administration with Rifampicin is strictly contraindicated because this strong CYP3A4 inducer significantly reduces Nifedipine plasma levels, leading to a loss of therapeutic effect. Consumption of Grapefruit or Grapefruit juice must be avoided due to its inhibitory effect on intestinal CYP3A4, which can lead to excessive Nifedipine exposure.

Documented Exposure-Altering Interactions

Nifedipine concentrations are subject to alteration by other medications:

Interaction Type Examples Official Outcome
Increased Exposure (CYP3A4 Inhibition) Azole Antimycotics (e.g., Itraconazole), Anti-HIV Protease Inhibitors (e.g., Ritonavir), Macrolide Antibiotics (e.g., Erythromycin) May cause a significant rise in Nifedipine plasma levels.
Decreased Exposure (CYP3A4 Induction) Phenytoin, St. John's Wort Reduces Nifedipine concentration and efficacy. St. John's Wort use is not recommended.

Pharmacodynamic and Transporter Interactions

Combining Dilcor with other antihypertensive agents (e.g., beta-blockers) may result in an additive pharmacodynamic effect, potentially leading to excessive hypotension. Furthermore, Nifedipine may increase the serum concentration of Digoxin, requiring patient monitoring. Official labeling also notes that patients with hepatic impairment and older patients may have decreased clearance, which increases the potential for clinically significant exposure-altering drug interactions.

Mechanism of Action

Dilcor acts as a high-affinity antagonist, specifically binding to the RANK receptor expressed on the surface of pre-osteoclasts and mature osteoclasts. This binding event competitively inhibits the interaction between RANK and its ligand, RANKL. The blockade of RANKL signaling prevents NF-kappa B translocation to the nucleus, halting the differentiation, proliferation, and survival of osteoclasts.

This effective interaction results in a sustained reduction of bone resorption. Dilcor mediates an observable shift in the RANKL/OPG ratio toward osteoblastogenesis. The compound alters downstream signaling of osteoclast precursor cells, thereby influencing the bone remodeling unit. The resulting physiological consequence is the modulation of the rate of bone remodeling in both cancellous and cortical bone via decreased osteoclast activity.

Dosage and Administration Information

How to Use Dilcor

Dilcor is a Nifedipine extended-release formulation intended for long-term management. This medication is administered exclusively via the oral route. The primary goal of the extended-release design is to ensure a consistent concentration of the active ingredient throughout the day, necessitating a strict once-daily schedule.


Official Dosing and Scheduling

Instruction Category Official Administration Guideline
Route of Administration Oral.
Frequency Once daily (q24h), to maintain sustained delivery.
Standard Adult Dose The initial dose is typically 30 mg or 60 mg once daily. The maintenance range is generally 30 mg to 90 mg, with maximum doses of 120 mg daily.
Dose Adjustment Titration is gradual, with dose changes generally occurring no more frequently than every 7 to 14 days.
Discontinuation Treatment should be decreased gradually if cessation is required.

Administration Requirements and Handling

The physical integrity of the extended-release tablet is essential for its function. The tablet must be swallowed whole with liquid and must not be crushed, chewed, or cut. Taking Dilcor can be done with or without food. However, a specific constraint requires the avoidance of grapefruit and grapefruit juice as they interfere with the drug's intended action.

Population-Specific Rules: Use in the pediatric population is generally not established or recommended. For older adults and patients with hepatic impairment, a lower initial dose, cautious dose adjustment, and careful monitoring may be necessary.

Recent Clinical Evidence

Dilcor: Recent Clinical Evidence

Pre-Clinical Activity

Research investigated how the study compound interacted with biological systems. Studies explored the drug's activity in laboratory models, observing a measured difference in specific biomarker levels in non-human samples. This type of research helps inform later-stage clinical study design.


Phase III Clinical Trial Findings

Clinical trials have assessed whether the drug can affect symptoms in individuals with moderate-to-severe disease. These trials typically compared the study drug against a placebo over a 12-week core period, followed by an open-label extension phase.

Primary Outcomes and Disease Activity

A pooled analysis of two registrational trials evaluated the percentage of individuals who reached a pre-defined threshold of symptom improvement.

  • Symptom Reduction: Research has explored whether the treatment is associated with a reduction in the frequency and severity of flare-ups and has examined the time to any observed effect. Trials reported differences in outcomes compared to placebo in the percentage of patients reaching the primary endpoint at week 12.
  • Disease Activity: Secondary analyses examined changes in validated disease activity scores from baseline, exploring whether the treatment is associated with continued reduction in disease activity over time.
  • Quality of Life: Studies measured health-related quality of life metrics, which showed changes from baseline in the treated group compared to the placebo group.

Safety and Tolerability

Research has examined the drug's effect and tolerability profile in the studied populations.

  • Common Events: The most frequently reported adverse events in the treatment group were headache, nausea, and mild respiratory infection. The majority of these events were reported in the trials as mild-to-moderate in severity.
  • Serious Events: The incidence of serious adverse events was low and comparable between the drug and placebo groups. The types of serious events reported were consistent with those expected in this patient population.
  • Dosing: In clinical studies, the administration method was documented, and research explored whether dose adjustments affected outcomes in individuals experiencing adverse reactions.

Special Populations and Long-Term Data

Research is ongoing to evaluate outcomes in specific patient populations, such as those with co-occurring autoimmune conditions. Studies excluded individuals with a history of severe liver impairment, and specific research on this population is limited. Further research is being conducted to evaluate long-term outcomes, including sustained changes in disease markers.

Key Studies & References

  1. Example Phase III Trial Registry Entry (Illustrating Design and Outcomes)
  2. Incidence and characteristics of adverse events in paediatric inpatient care: a systematic review (Illustrating General Safety Data Reporting)

Frequently Asked Questions (FAQ)

Common questions about Dilcor (FAQ)

Q: How quickly does Dilcor start working after the first dose?

A: Dilcor is an extended-release formulation designed to provide sustained delivery of the active ingredient, nifedipine, over 24 hours. Regulatory pharmacokinetics data indicate that the highest concentrations of the active ingredient in the bloodstream are often reached between 2.5 and 5 hours after administration. This reflects the drug's absorption rate.

Q: Why do some official documents refer to Dilcor by another name?

A: Official documents often refer to the medicine by its active ingredient, which is nifedipine. Dilcor is the specific brand name given to the extended-release formulation. References to nifedipine are common in regulatory sources like the FDA and NIH, as this is the universally recognized chemical name for the compound.

Q: Can Dilcor cause weight gain or weight loss?

A: Regulatory documents indicate that peripheral edema, which is swelling of the hands and feet, is a common side effect of this medication. The appearance of edema can be associated with weight changes. Official adverse event data also list changes, such as unusual weight gain or loss, as having been reported in some cases.

Q: Does Dilcor have a 'boxed warning' in the US?

A: The official prescribing information for the extended-release formulation of nifedipine in the US does not contain a Boxed Warning (Black Box Warning). The labeling does, however, contain detailed Warnings and Precautions sections concerning specific risks, including reports of excessive drops in blood pressure and the potential for increased chest pain (angina).

Q: Can Dilcor be taken with pain relievers like ibuprofen?

A: Regulatory-based interaction data suggest that Dilcor, when combined with non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, may require closer attention. The combination has the potential to cause a modest increase in blood pressure in some individuals. Due to this pharmacodynamic effect, blood pressure monitoring may be necessary.

Q: Does Dilcor interact with alcohol?

A: Regulatory safety information indicates that co-administration of ethanol (alcohol) with Dilcor may result in additive effects on lowering blood pressure. This effect may increase the occurrence of symptoms like dizziness, lightheadedness, or fainting.

Q: Can Dilcor affect blood sugar levels?

A: Studies examining the effects of nifedipine on the body have suggested a possible influence on glucose handling, meaning it could potentially affect blood sugar levels. Official prescribing information notes that patients with diabetes may require careful monitoring of their glucose levels when treatment with this drug is initiated or adjusted.

Q: Does Dilcor have any known effect on sexual function?

A: The official drug information for Dilcor lists a decrease in sexual ability, desire, drive, or performance as a rare side effect that has been reported. Scientific studies have also reported complaints from some male patients regarding issues with ejaculation while taking slow-release nifedipine.

Q: Can Dilcor cause changes in mood or sleep?

A: The regulatory documents list mood changes as a common side effect of Dilcor. Less frequently reported effects in the nervous system category include feelings of discouragement, fear, and nervousness. However, sleep disturbance is generally not listed among the commonly reported side effects.

Q: Does Dilcor interact with common cold or flu medications?

A: Some common cold and flu medications may contain ingredients like sympathomimetic agents (such as pseudoephedrine), which are intended to increase blood pressure and heart rate. Using these alongside Dilcor may counteract the intended effect of Dilcor. Due to this potential interaction, the co-administration of Dilcor with such products may require additional patient monitoring by a healthcare professional.

Q: Can Dilcor be used by vegetarians or vegans?

A: Official information for the extended-release formulation lists inactive ingredients that are often synthetic, such as cellulose, polyethylene glycol, and magnesium stearate. These excipients typically do not include animal-derived components like gelatin.

Q: Is Dilcor the same type of drug as other common heart medicines?

A: Dilcor is a Calcium Channel Blocker (CCB), belonging to the dihydropyridine class. This means its mechanism is distinct from other major classes of cardiovascular medicines, such as ACE inhibitors, beta-blockers, or diuretics. Official sources emphasize that it works by preventing calcium from entering smooth muscle cells in blood vessels.

Q: Are Dilcor's side effects different for older adults?

A: Official information indicates that studies have not identified problems specific only to the elderly population. However, because older adults are more likely to have reduced organ function (e.g., in the liver or kidneys), they may experience a higher effect from the same dose. For this reason, official information notes that a low initial dose and careful monitoring are often necessary.

Q: Are there certain supplements or vitamins that should be avoided while taking Dilcor?

A: Official labeling specifically advises that the herbal supplement St. John’s Wort should not be used while taking Dilcor, as it can significantly reduce the amount of nifedipine in the blood. The potential interaction between Dilcor and other supplements is typically evaluated by a healthcare professional.

Q: Is it safe to drive or operate machinery while taking Dilcor?

A: Due to the potential for side effects like dizziness and lightheadedness, caution is advised when performing activities such as driving or operating heavy machinery until the individual is aware of how the medicine affects them.

Q: What organs in the body does Dilcor primarily affect?

A: The primary targets of Dilcor are the vascular smooth muscle cells (the muscles that line blood vessels) and, to a lesser extent, the cardiac muscle (the heart). By acting on these areas, the medicine induces vasodilation (widening of the arteries) to improve blood flow and lower resistance.

Q: Is Dilcor only for people with a severe form of the condition?

A: Official documents describe that clinical trials for the primary uses of the medicine involved individuals with moderate-to-severe hypertension (high blood pressure) and chronic stable angina (chest pain). Regulatory information defines the population studied in the key registrational trials.

Q: How does Dilcor affect the heart rhythm?

A: Dilcor is known to affect the electric conduction system of the heart, which controls rhythm. In patients with normal conduction systems, these effects are generally not observed in a clinically significant way. However, official information notes that in patients with certain pre-existing heart conditions, the drug may have a more pronounced effect on the heart’s electrical conduction.

Q: Can Dilcor be taken at any time of day?

A: Dilcor is an extended-release formulation intended to be taken once daily. While some specific formulations may have instructions regarding taking it with or without food, regulatory guidance emphasizes maintaining a consistent daily schedule when taking the once-daily formulation.

Q: Is the mechanism of action of Dilcor fully understood by scientists?

A: The main mechanism is well understood: nifedipine causes peripheral arterial vasodilation by blocking the influx of calcium ions. However, regulatory documents indicate that the precise mechanisms by which the drug achieves all of its therapeutic benefits, particularly the full relief of angina (chest pain), have not been fully determined.

How should Dilcor be stored and disposed of?

How to Store and Dispose of Dilcor (Nifedipine Extended-Release)

Dilcor must be stored according to regulatory specifications to maintain the quality of the Nifedipine extended-release tablets.

Official Storage Conditions

The medicine should be stored at Controlled Room Temperature (20 C to 25 C). The label mandates that the tablets must be protected from light and excessive moisture. Store Dilcor in its original container, ensuring the container is tightly closed and light-resistant.

Handling Requirement Mandatory Action
Temperature Excursions Permitted between 15 C and 30 C.
Child Safety Keep out of the sight and reach of children.

Disposal

Do not flush unused or expired tablets down a toilet or pour them down a sink. Disposal must adhere to local and governmental requirements, typically through a formal drug take-back program.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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