Diclac

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Diclac

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Medically reviewed

Laura Arias

Last updated on 22/12/2025

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 Diclac

Diclac Quick Facts

Property Description
Active Ingredient Diclofenac (typically as Sodium or Potassium salt)
Form Tablets, gels, solutions for injection, suppositories
Pharmacological Class Nonsteroidal Anti-Inflammatory Drug (NSAID)
General Purpose Symptomatic relief of inflammation, pain, and fever
Origin Synthetic compound (derivative of phenylacetic acid)

Diclac is a medicinal product designed to alleviate discomfort by acting on the body's processes that cause inflammation, pain, and fever. Its foundational identity is rooted in its active substance, Diclofenac, which defines its pharmacological behavior and general utility.

Identity, Class, and Active Ingredient

Diclac is a pharmaceutical preparation containing the active ingredient Diclofenac, a substance that belongs to the Nonsteroidal Anti-Inflammatory Drug (NSAID) class. This classification signifies that the medicine is used primarily for its anti-inflammatory and pain-relieving effects. This active substance, a synthetic compound derived from phenylacetic acid, is the core component responsible for the drug’s primary effects. Diclofenac is widely recognized and is included on standard lists of essential medicines.

Available Forms and General Purpose

Diclac is manufactured in multiple dosage forms, including oral forms like tablets, solutions for injection, and topical forms such as gels, allowing for flexible administration. Its overall purpose is to provide broad symptomatic relief by addressing the chemical causes of discomfort associated with various conditions. Diclofenac is used to treat painful and inflammatory conditions, which includes scenarios like acute muscle strain or joint discomfort. By modulating the body's response, Diclac offers a general benefit against three key symptoms: inflammation, pain, and elevated body temperature (fever).

Differentiation and Pharmacological Context

As a brand of Diclofenac, Diclac is recognized for its rapid onset of action in certain formulations. It is designated as an NSAID because it functions by selectively modulating a core biochemical process—the production of prostaglandins. NSAIDs function as Cyclooxygenase inhibitors, blocking the enzymes responsible for creating these signaling chemicals. By interrupting the cascade that initiates the physical symptoms of pain and inflammation, Diclac ensures its general therapeutic effect is targeted toward both processes.

Regulatory References

  1. WHO Model Lists of Essential Medicines
  2. NIH MedlinePlus Drug Information
  3. Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) - NCBI Bookshelf

What side effects are possible with Diclac?

Diclac (diclofenac) is a non-steroidal anti-inflammatory drug (NSAID) with a safety profile primarily defined by risks of serious systemic events. Official regulatory warnings highlight two major classes of risk:

Serious Adverse Reactions

System Organ Class Serious Events Documented in Regulatory Sources
Cardiovascular/Vascular Increased risk of serious arterial thrombotic events, including myocardial infarction (heart attack) and stroke, which can be fatal. This risk may increase with higher doses (geq150 mg/day) and longer duration. The product is contraindicated in patients with established heart failure (NYHA class II-IV), ischaemic heart disease, peripheral arterial disease, or cerebrovascular disease.
Gastrointestinal Increased risk of gastrointestinal bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These events may occur without warning symptoms and are more common in elderly patients.
Hepatic/Renal Serious liver injury (hepatotoxicity), kidney injury, and fluid retention (oedema) have been reported. Liver and renal function should be monitored during prolonged use.
Immune System/Skin Severe allergic reactions (anaphylaxis) and serious, potentially fatal, skin reactions (e.g., Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis) have been documented.

Common Adverse Reactions

Commonly reported side effects include gastrointestinal disturbances (such as nausea, vomiting, diarrhoea, dyspepsia, and abdominal pain), headache, dizziness, and mild rash.

Safety Considerations

Use of Diclac is contraindicated in the third trimester of pregnancy due to risks to the fetus. The lowest effective dose should be used for the shortest duration necessary to control symptoms, consistent with its classification as an NSAID.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose of diclofenac, the active substance in Diclac, requires immediate medical attention. The severity of overdose is associated with the amount ingested, with significant toxicity reported at doses several times the therapeutic level. Overdose can be very harmful to both children and adults.


Documented Overdose Manifestations

Initial, non-severe presentations commonly include nausea, vomiting, diarrhea, stomach pain, and mild central nervous system effects such as dizziness or headache. However, an overdose can rapidly lead to serious and life-threatening complications.


Serious Outcomes and Emergency Actions

A large overdose can result in major internal complications affecting several physiological systems. Serious outcomes reported with acute NSAID overdose include:

  • Gastrointestinal Bleeding (indicated by vomiting blood or having bloody, black, or tarry stools).
  • Acute Renal Failure (little or no urine output).
  • Severe Central Nervous System Effects (including confusion, agitation, delirium, seizures, and coma).

If any signs of an overdose or a severe reaction, such as chest pain, shortness of breath, weakness on one side of the body, or significant gastrointestinal distress, occur, emergency medical help must be sought right away. The patient’s prognosis is often dependent on the promptness of treatment.

Therapeutic Uses of Diclac

The core therapeutic function of Diclac is to provide symptomatic relief by moderating symptoms related to pain, inflammation, and fever in situations where patients experience heightened symptoms. In clinical practice, Diclac (Diclofenac) is applied across various therapeutic domains involving physiological responses to injury or disease.


Symptomatic Relief for Chronic Arthritis and Musculoskeletal Pain

Diclac is commonly applied in therapeutic contexts involving persistent inflammation and pain, particularly in the management of chronic joint conditions. It helps address symptom clusters of stiffness, swelling, and chronic discomfort seen in conditions like Osteoarthritis, Rheumatoid Arthritis, and Ankylosing Spondylitis. By targeting these symptoms, it offers supportive therapeutic benefit that contributes to easing the overall symptom load and supports the patient during symptomatic periods.


Easing Acute and Episodic Discomfort

The medication is relevant in clinical settings requiring short-term symptomatic support for sudden, acute episodes, including soft-tissue injuries such as sprains and strains, and pain following postoperative procedures. Furthermore, it is used to address pronounced symptoms that manifest in acute, recurrent patterns, such as the pain of primary dysmenorrhea (menstrual cramps) and acute gout flare-ups. Diclac helps ease challenging symptoms that create temporary functional strain, assisting with maintaining functional stability during these difficult episodes.


Quick Fact: Relief for Inflammation, Pain, and Stiffness

Focus Domain Symptom Category Addressed Core Benefit Provided
Chronic Joint Health Stiffness, Chronic Discomfort, Swelling Contributes to easing distress
Acute Musculoskeletal Localized Pain, Functional Strain, Injury Swelling Supports functional stability
Episodic Pain Menstrual Cramps, Gout Attacks, Migraine Pain Offers symptomatic relief to cope steadily

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Diclac (Diclofenac) is governed by strict population eligibility rules defined by regulatory authorities worldwide.

Contraindicated Populations (Must Not Use)

Official labeling contraindicates Diclac use for several groups, including patients with a known hypersensitivity to diclofenac, aspirin, or any other Nonsteroidal Anti-Inflammatory Drug (NSAID). Use is also prohibited in patients with an active gastric or intestinal ulceration or bleeding, severe heart failure (NYHA Class II–IV), or in the setting of coronary artery bypass graft (CABG) surgery.

Age and Physiological Restrictions

The medicine is contraindicated during the third trimester of pregnancy due to risks to the fetus. Use during the first and second trimesters is not recommended unless strictly necessary. Similarly, use while breastfeeding is generally not recommended. For the pediatric population, while some oral forms are approved for children 12 years and older, safety is not established for many applications in younger patients.

Condition-Specific Limitations

Patients with severe renal impairment or severe hepatic impairment are typically contraindicated from using Diclac. Those with established ischemic heart disease or cerebrovascular disease must also not use this medicine. The elderly are permitted to use Diclac, but are explicitly classified as requiring caution due to a heightened risk of gastrointestinal and renal complications.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Regulatory documentation defines Diclac's interaction profile through managing both pharmacodynamic risks and pharmacokinetic alterations. Co-administration with other Systemic Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), including COX-2 inhibitors, should be avoided due to the potential for additive adverse effects. The intravenous formulation is formally contraindicated with Anticoagulants. Diclac is also contraindicated for perioperative pain in the setting of Coronary Artery Bypass Graft (CABG) surgery.

Pharmacokinetic and Pharmacodynamic Effects

Interaction Type Interacting Substances/Conditions
Increased Exposure Lithium, Digoxin, and Methotrexate plasma concentrations may be raised, and Voriconazole increases Diclofenac's AUC and Cmax (via CYP enzyme inhibition).
Increased Bleeding Risk Anticoagulants, Antiplatelet Agents, SSRIs, and Systemic Corticosteroids enhance the risk of serious gastrointestinal bleeding. Alcohol intake also carries this documented risk.
Reduced Efficacy Diclac may diminish the antihypertensive and natriuretic effects of ACE Inhibitors, ARBs, and Diuretics.

Administration and Population Notes

The risk of renal function deterioration when co-administered with ACE Inhibitors or ARBs is specifically heightened in elderly, volume-depleted, or renally impaired patients. Furthermore, certain oral Diclac formulations have administration requirements to be taken on an empty stomach to prevent a documented reduction in effectiveness.

Mechanism of Action

Diclac, containing the active substance diclofenac, operates primarily as an inhibitor of the cyclooxygenase (COX) enzymes, specifically COX-1 and COX-2. This molecular interaction is non-selective and results in the intracellular block of the enzymatic conversion of arachidonic acid into prostaglandin precursors (prostaglandin G2 and H2).

This inhibition modulates the synthesis of various downstream eicosanoids, including prostaglandins and thromboxanes, which are crucial lipid mediators derived from the arachidonic acid cascade. The resulting system-level physiological consequence is a reduction in the circulating and local tissue concentrations of these pro-inflammatory mediators. Additionally, diclofenac may inhibit the thromboxane-prostanoid receptor and modulate arachidonic acid release and uptake. It also influences cellular signaling by activating the nitric oxide-cGMP pathway and potentially blocking acid-sensing ion channels in neural tissues, contributing to altered nociceptive signal transmission. Diclac demonstrates accumulation within inflamed tissue and synovial fluid, which contributes to localized pharmacodynamic effect.

Dosage and Administration Information

How Diclac is Used: Administration and Dosing

The use of Diclac (Diclofenac) involves specific routes, dose ranges, and administration constraints designed for proper use. This section describes the typical usage parameters for the medication.


Routes and Dosing Parameters

Administration Route Common Adult Dosing Regimen Maximum Daily Dose (Example)
Oral (Tablets) 100 mg to 150 mg total daily dose, typically divided 2–3 times a day for chronic conditions. Generally 150 mg
Parenteral (IM/IV) 75 mg per dose, repeatable after 6 to 8 hours if necessary. 150 mg
Topical (Gel) Applied to the affected area; dosage is often measured using a dosing card. Varies by formulation

Dosing regimens may vary by the specific salt (sodium or potassium) and formulation. A general pharmacological principle for this medication is the use of the lowest effective dose for the shortest duration possible to meet treatment goals.


Administration Requirements and Special Instructions

Usage instructions for Diclac depend on the specific formulation:

  • Enteric-Coated/Extended-Release Forms: Tablets designed for delayed or extended release are intended to be swallowed whole. Crushing, breaking, or chewing these tablets can interfere with the intended release rate and may cause local irritation.
  • Acute Pain/Migraine (Oral Powder): When provided in powder form, the medication is typically mixed with water and consumed on an empty stomach to facilitate absorption.
  • Intravenous Infusion: In parenteral settings, Diclac is administered as a slow, controlled infusion (for example, over 30 to 120 minutes) rather than a rapid bolus injection.
  • Older Adults: Dosing for older patients typically follows the principle of using the lowest effective dose for the shortest possible duration due to potential variations in sensitivity.

Recent Clinical Evidence

Research Evidence / Overview of Studies


Exploration of Mechanism and Initial Evidence

Research explored the drug's interaction with immune pathways implicated in the inflammatory response. Early-stage (Phase 1 and 2) studies investigated endpoints related to severity and duration of flares in adults, noting that the mechanism involves inhibition of cyclooxygenase (COX) enzymes.


Phase 3 Trial Findings

A pivotal multi-center Phase 3 trial, involving participants with conditions like osteoarthritis, served as the primary evidence base. The trial examined the investigational drug alongside a placebo over defined periods.

  • Primary Endpoint: The trial documented outcomes related to disease progression according to pre-defined criteria, such as changes in pain and functional scores.
  • Symptom Measures: Secondary analyses investigated changes in patient-reported symptoms, specifically focusing on measures of pain and mobility.

Long-term and Comparative Research

Research has investigated the drug in evaluations of long-term maintenance protocols, particularly for chronic pain management. Some studies have investigated the drug alongside older treatments, though head-to-head data directly comparing all formulations remains limited. One trial used a specific concentration in its evaluation of the potential for maintaining symptom stability for up to two years.


Safety Events Documented in Trials

Adverse events were collected across all phases of the clinical program. Clinical trials documented the occurrence of events such as headache, injection site reactions (for topical/injectable forms), and mild upper respiratory infections in a small percentage of participants. Researchers documented instances of elevated liver enzymes. Interactions with certain co-administered drugs were examined in select patient populations. Researchers continue to explore the long-term safety profile.

Frequently Asked Questions (FAQ)

Common questions about Diclac (FAQ)

Q: What is the difference between Diclac and the drug sold under the brand name Voltaren?

Diclac contains the active ingredient diclofenac. Voltaren is simply another widely recognized brand name for the exact same substance, a non-steroidal anti-inflammatory drug (NSAID). Both brands contain the same primary active ingredient, though they may offer different formulations of the drug.


Q: Why is Diclac usually only available with a prescription?

Regulatory authorities reclassified oral diclofenac as prescription-only in many regions due to a small but increased risk of serious cardiovascular problems, like heart attack or stroke. Regulatory guidance indicates that a healthcare professional's assessment of this risk is required prior to use. This ensures safe use consistent with the drug's established risk profile.


Q: Is Diclac considered a stronger pain reliever compared to common over-the-counter options?

Clinical studies have investigated diclofenac's effectiveness compared to common over-the-counter pain relievers like ibuprofen. Official information indicates that, for acute pain relief, certain diclofenac formulations provide relief that is comparable to or, in some cases, greater than standard OTC NSAIDs. Information regarding suitable pain relief is determined by healthcare professionals, based on a patient's condition.


Q: What are the main differences between Diclac and ibuprofen?

Both medicines are classified as non-steroidal anti-inflammatory drugs (NSAIDs). Diclofenac is recognized in medical literature for having a particularly strong anti-inflammatory effect. While both carry similar potential risks, official warnings emphasize diclofenac's cardiovascular risk more prominently than many other NSAIDs.


Q: How does the action of Diclac compare to Naproxen?

Both Diclac (diclofenac) and naproxen are NSAIDs that work by reducing pain and inflammation. Regulatory warnings state that diclofenac is associated with a greater risk of cardiovascular events compared to naproxen. Official pharmacological reviews suggest diclofenac may have a greater impact on the COX-2 enzyme pathway than naproxen.


Q: Does Diclac treat inflammation differently than Acetaminophen (Tylenol)?

Yes, Diclac is an NSAID, which works by blocking the body's processes that cause pain, fever, and inflammation. Acetaminophen (Tylenol) is not an NSAID; it relieves pain and fever primarily by acting on the central nervous system. Acetaminophen does not significantly treat inflammation in the body tissues.


Q: How does the topical Diclac gel differ from the oral tablets in terms of effects on the body?

The regulatory information indicates that the gel's absorption into the bloodstream is significantly lower than that of the oral tablet. This difference means the gel concentrates the medicine locally in the inflamed tissue. This localized effect helps minimize the risk of systemic, or body-wide, side effects.


Q: Can Diclac cause ringing in the ears (tinnitus)?

Yes, official regulatory documents list tinnitus, which is described as ringing or buzzing in the ears, as a recognized potential side effect. This is included in the adverse reaction sections of the official product information for diclofenac.


Q: Does Diclac carry a boxed warning about potential cardiovascular risks, such as heart attack or stroke?

Yes. The FDA requires diclofenac to carry a Boxed Warning, which is the agency's most serious warning. This warning highlights the increased risk of potentially fatal cardiovascular events (such as heart attack or stroke) and serious gastrointestinal events (like bleeding and ulcers).


Q: What are the specific signs that may indicate a serious side effect from Diclac is occurring?

The regulatory documents describe several serious adverse events. Symptoms associated with these events include: passing dark or bloody stools (indicating GI bleeding), severe, unexplained chest pain, or a sudden onset of yellowing of the skin or eyes (jaundice). Other symptoms include sudden weakness, slurred speech, or unexplained swelling.


Q: What is the official information regarding Diclac's potential effect on blood pressure?

Official warnings state that using Diclac can be associated with the development of new hypertension or the worsening of high blood pressure already present. Regulatory guidance indicates that blood pressure monitoring is necessary throughout the course of treatment.


Q: What is the difference between the forms Diclofenac Sodium and Diclofenac Potassium?

The two most common forms, diclofenac sodium and diclofenac potassium, differ in how quickly the medicine is released. Diclofenac Potassium is typically used in immediate-release formulations that offer a quicker onset of action. Diclofenac Sodium is often used in delayed- or extended-release forms intended for managing chronic conditions.


Q: What is the purpose of the enteric coating found on some Diclac tablets?

The enteric coating is a safety feature on certain tablets. Official prescribing information states the coating prevents the tablet from dissolving in the stomach's strong acid environment. The coating allows the medicine to pass into the intestine, which protects the stomach lining from potential irritation and damage.


Q: What conditions, besides arthritis, are officially listed as indications for Diclac use?

Official regulatory indications go beyond general arthritis and joint discomfort. Depending on the specific formulation, diclofenac is officially approved to treat conditions such as rheumatoid arthritis, ankylosing spondylitis, gouty arthritis, primary dysmenorrhea (painful periods), and certain types of acute migraine headaches.


Q: Is it permissible to take Diclac if I have a history of asthma or nasal polyps?

Official regulatory labeling contraindicates the use of Diclac in patients who have previously experienced asthma attacks, angioedema, or acute rhinitis after taking aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs). This is due to the potential for a severe allergic-type reaction.


Q: Does using Diclac have any known effect on drug screening tests?

According to regulatory substance classifications, Diclac is a non-steroidal anti-inflammatory drug (NSAID). It is not classified as a controlled substance like a narcotic or opioid. Therefore, it is not typically detected in standard drug screening tests.


Q: How quickly can a person usually expect Diclac to begin providing pain relief?

Official pharmacokinetic data indicates that relief can begin relatively quickly, especially with immediate-release formulations. For the immediate-release potassium salt, peak blood levels are typically reached within about one hour in individuals who are fasting. The exact time it takes to feel relief depends on the specific formulation being used.

How should Diclac be stored and disposed of?

How to Store and Dispose of Diclac?

Strict storage and disposal requirements are essential to maintain the quality of Diclac (diclofenac) and prevent environmental harm.

Official Storage Requirements

Condition Requirement
Temperature Store below 25 C in a dry place.
Handling Keep in original, properly labeled containers. Wash hands after applying topical gel (unless treating hands). Avoid exposure of treated skin areas to natural or artificial sunlight.
Stability Some topical gels have a 6-month in-use shelf-life after first opening.
Safety Store all forms of the medication locked up and out of sight to prevent access by children.

Official Disposal Instructions

Unused or expired Diclac should not be flushed down a toilet or sink. The preferred method of disposal is a drug take-back program (e.g., community collections). If a take-back program is unavailable, unused medication should be mixed with an unpalatable substance (such as dirt or coffee grounds) and sealed in a container before being discarded in household trash. Specifically, any unused topical product or waste must be disposed of in accordance with local requirements to avoid release into the aquatic environment.

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

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