Diclostar

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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 Diclostar

Property Description
Active ingredient Diclofenac (as sodium or potassium salt)
Form Tablet, capsule, injection, topical gel, suppository
Pharmacological class Nonsteroidal Anti-Inflammatory Drug (NSAID)
Common use Reduction of pain, inflammation, and fever
Origin Synthetic compound (Phenylacetic acid derivative)

What Type of Medicine is Diclostar?

Diclostar is a trade name for a medicinal product containing the active ingredient Diclofenac, which belongs to the widely recognized Nonsteroidal Anti-Inflammatory Drug (NSAID) class. Chemically, Diclofenac is a synthetic compound derived from phenylacetic acid. This classification as an NSAID immediately defines its therapeutic role, confirming its function as a systemic agent used to address conditions characterized by inflammation and pain. The active substance, Diclofenac, is recognized for its efficacy in managing pain and inflammation.

Composition and Available Forms of Diclofenac

The fundamental composition of Diclostar is the single active ingredient Diclofenac, which is typically prepared as either the sodium or potassium salt, enabling various routes of administration. Diclofenac preparations, such as Diclostar, are clinically recognized for their versatility, being manufactured into a comprehensive array of dosage forms, including traditional tablets and capsules, alongside specialized preparations such as injection solutions, suppositories, topical gels, and ophthalmic solutions. A key differentiating feature is the use of the potassium salt in certain formulations, which is specifically designed for faster initial absorption compared to the sodium salt, often preferred in scenarios requiring rapid onset of symptomatic relief.

What is the General Therapeutic Purpose of Diclostar?

The general therapeutic purpose of Diclostar is to provide symptomatic relief by modulating the body's physiological response to injury or illness. As an NSAID, its functional identity is rooted in its ability to inhibit the synthesis of prostaglandins, the chemical mediators that cause excessive sensitivity to pain and induce localized inflammation. Consequently, its utility is focused on simultaneously reducing the experience of pain, alleviating the associated signs of inflammation (such as redness and swelling), and helping to lower an elevated body temperature or fever. Diclofenac is used to reduce inflammation and pain, which is consistent with clinical practice.

Regulatory References

  1. WHO Model List of Essential Medicines
  2. Diclofenac: MedlinePlus Drug Information (NIH/NLM)

What side effects are possible with Diclostar?

Possible Side Effects and Safety Information

Diclostar (Diclofenac), as a Nonsteroidal Anti-Inflammatory Drug (NSAID), has an official safety profile categorized by regulatory authorities, highlighting adverse effects across several organ systems.

Frequency-Classified Adverse Reactions

The safety classification differentiates between common and rare occurrences. Common reactions documented in regulatory sources include central nervous system effects such as headache and dizziness, and gastrointestinal effects like nausea, vomiting, diarrhea, dyspepsia, abdominal pain, and flatulence. Additionally, elevated liver enzymes (transaminases) and rash are also classified as common. Reactions classified as rare or very rare include serious hypersensitivity responses, gastrointestinal ulceration and bleeding, and severe skin disorders.

Serious Adverse Reactions and Systemic Risks

The official label documents serious, potentially life-threatening risks. These include the potential for major Cardiovascular Thrombotic Events, such as myocardial infarction and stroke, which may occur early in treatment and whose risk can increase with the duration of use. Similarly, severe Gastrointestinal events, including ulceration, bleeding, or perforation, are significant documented risks that also increase with the duration of use. The medication is also associated with rare but serious hepatic (liver failure) and renal (acute kidney failure) events.

Population-Specific and Duration-Related Safety

Safety notes specify that older adults face a greater inherent risk for serious gastrointestinal adverse events. Use is generally restricted in specific high-risk patient populations. Furthermore, use is officially contraindicated for the management of pain following Coronary Artery Bypass Graft (CABG) surgery and in patients with known active peptic ulcer.

Overdose and Emergency Response

An acute overdose of Diclostar (Diclofenac) may be asymptomatic or initially present with minor, self-limiting gastrointestinal complaints such as epigastric pain, nausea, and vomiting. Documented neurological signs can include drowsiness (lethargy), confusion, and general hypotonia.

Regulatory documents list potential severe or life-threatening sequelae, including acute renal failure, gastrointestinal bleeding, convulsions (seizures), metabolic acidosis, and coma. These outcomes primarily affect the renal, gastrointestinal, and central nervous systems.

No specific antidote is known for acute Diclofenac toxicity; therefore, official management is limited to symptomatic and supportive care. When an overdose is suspected, regulatory guidance advises that patients contact a poison control center for recommendations.

Immediate medical attention is required for any severe symptoms, and regulators mandate seeking help for complications such as an anaphylactic reaction. Supportive measures may involve gastric lavage or the administration of activated charcoal to reduce absorption, along with monitoring of renal function and acid-base status. Special consideration is given to management procedures in pediatric patients regarding activated charcoal dosage.

Therapeutic Uses of Diclostar

What Diclostar Treats: Main Uses and Benefits

Diclostar (Diclofenac) is relevant for symptomatic management as a Non-Steroidal Anti-Inflammatory Drug (NSAID). The medication is relevant for easing symptoms related to physical discomfort within appropriate therapeutic domains.

It is applied across domains where additional symptomatic support is needed, particularly in conditions where functional stability becomes affected. This includes relieving symptoms associated with inflammatory joint conditions like osteoarthritis and rheumatoid arthritis, acute manifestations such as sprains and postoperative pain, and specific episodic pain patterns including menstrual cramps (primary dysmenorrhea) and acute migraine attacks. The medication also supports general well-being during symptomatic phases by helping to manage an elevated body temperature (fever).

“Diclostar assists with managing symptoms that create noticeable physiological strain, and may help patients cope more steadily when symptoms interfere with routine activities.”

Quick Fact: Relief for Inflammatory Pain

Diclostar is applied in clinical settings that involve acute or episodic symptom patterns, such as the pain and stiffness associated with an arthritis flare-up. It provides support that helps ease the overall symptom burden, and assists with maintaining functional stability when symptoms are more noticeable.

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Diclostar (Diclofenac) is a Nonsteroidal Anti-Inflammatory Drug (NSAID) whose use is strictly governed by regulatory eligibility rules defined by government authorities.

Populations for Whom Use is Contraindicated

The medicine is formally contraindicated and must not be used by patients with the following conditions:

  • Known hypersensitivity or allergy to diclofenac, aspirin, or any other NSAID, including those who have experienced allergic-type reactions like asthma or urticaria.
  • Treatment of perioperative pain in the setting of Coronary Artery Bypass Graft (CABG) surgery.
  • Late pregnancy, starting at 30 weeks gestation and later.

Conditional Use and Special Populations

For other groups, eligibility is subject to specific regulatory conditions:

Population / Condition Official Regulatory Status
Advanced Renal or Severe Heart Failure Avoid use unless benefits are determined to strictly outweigh risk.
Recent Myocardial Infarction (MI) Avoid use due to risk of recurrent thrombotic events.
Pregnancy (20 to 30 weeks) Limit use to the lowest effective dose for the shortest duration.
Pediatric Use Safety and effectiveness are typically not established for most systemic indications in children and adolescents.
Geriatric Patients Use requires caution and close monitoring due to increased risk of serious gastrointestinal and renal adverse events.

Eligibility is defined solely by these mandatory exclusion criteria and use limitations described in official prescribing information.

What should I know about interactions with other medicines?

Interaction Map: Interactions with other medicines and products — official regulatory information for Diclostar

Interaction Scope

  • Medicinal product categories with documented interactions: Other Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), Anticoagulants, Anti-platelet agents, Systemic Corticosteroids, Selective Serotonin-Reuptake Inhibitors (SSRIs), Diuretics, and Angiotensin Receptor Blockers/ACE Inhibitors.
  • Specific interacting medicines (if explicitly listed): Aspirin, Voriconazole, Digoxin, Lithium, and Methotrexate.
  • Mechanistic basis of interactions (only if stated in label): Pharmacodynamic additive risk (e.g., increased bleeding risk) and inhibition of metabolic clearance (e.g., resulting in increased diclofenac exposure with the CYP inhibitor, Voriconazole).
  • Timing-based interaction rules (if applicable): For immediate-release oral solution formulations, administration with food may cause a reduction in effectiveness.
  • Population-specific interaction notes (if applicable): Elderly, volume-depleted, or renally impaired patients are noted to have an increased risk of renal toxicity when co-administered with Diuretics or ACE Inhibitors/ARBs.
  • Interaction-related restrictions: Use is contraindicated for perioperative pain in the setting of Coronary Artery Bypass Graft (CABG) surgery. Concomitant use with alcohol is also avoided due to elevated risk of gastrointestinal bleeding.

Interaction Classifications (High-Level)

  • Interaction severity classification (as defined in official documents): Includes both Contraindicated Combinations (e.g., Aspirin, other NSAIDs) and Clinically Significant Interactions (e.g., Anticoagulants, Digoxin).

Resulting Interaction Structure

  • Official interaction statements: Co-administration with Aspirin or other systemic NSAIDs is contraindicated due to additive risk of serious gastrointestinal events. Diclofenac may cause increased serum concentrations of Digoxin and Lithium by inhibiting their clearance. The use with Anticoagulants and SSRIs increases the overall risk of bleeding. Diclofenac may also diminish the therapeutic effects of Diuretics and blood pressure medications like ACE Inhibitors/ARBs.
  • Connection to the overall interaction profile (2–4 sentences): The regulatory profile is structured around prohibiting Pharmacodynamic Risk Reinforcement, specifically where diclofenac enhances the bleeding or renal toxicity potential of other agents. It also addresses Pharmacokinetic Exposure Modification, noting both the increased concentration of co-administered agents and the potential for an inhibitor like Voriconazole to elevate diclofenac’s own levels. The label enforces mandatory restrictions based on concurrent substance use and specific clinical conditions.

Mechanism of Action

Molecular Mechanism: Inhibition of Prostanoid Synthesis

The mechanism of Diclostar (Diclofenac) is fundamentally rooted in its ability to intervene in molecular signaling pathways associated with eicosanoid production. The molecule acts through two principal mechanistic domains: enzyme inhibition and subsequent downstream signaling modulation.

The primary action is the non-selective, reversible inhibition of the Cyclooxygenase (COX) enzymes (both COX-1 and COX-2). This molecular blockade prevents the conversion of arachidonic acid into prostanoid mediators, such as **Prostaglandin E2 ( PGE2), which are key chemical signals. Halting this enzyme activity is the initial step that determines the molecule's subsequent physiological effects.

Physiological Mechanism: Modulation of Signaling Cascades

The reduced availability of prostanoids, especially PGE2, modulates critical physiological signaling cascades both locally and centrally. Peripherally, it reduces the heightened sensitivity of nociceptors (pain-sensing neurons) by reducing local mediator concentration, which elevates the threshold for signal transmission. Centrally, the mechanism constrains PGE2 production within the hypothalamus, which permits the resetting of an elevated thermoregulatory setpoint.

Dosage and Administration Information

The administration of Diclostar (Diclofenac) is characterized by the use of the lowest effective dose for the shortest duration consistent with symptomatic management. The medication is provided in various routes, with the specific formulation dictating the administration method.

Approved Routes and Regimens

Diclofenac is prepared in several forms, including oral tablets (immediate, delayed, and extended-release), topical preparations (gel, solution), rectal suppositories, and parenteral solution for injection.

Oral dosing for chronic conditions like osteoarthritis or rheumatoid arthritis typically ranges from 100 mg to 200 mg per day, administered in divided doses (e.g., 50 mg three times daily) or as a 100 mg extended-release tablet taken once daily. The total daily dose is generally limited to 150 mg for most indications.

Procedural Instruction Administration Principle
Form Integrity Delayed-release and extended-release tablets are swallowed whole and are not crushed, split, or chewed.
Timing Specific formulations, such as the powder for oral solution, are administered on an empty stomach as food may reduce the rate of absorption.
Population Dosing Treatment for older adults and individuals with hepatic impairment is initiated at the lowest dose.

Parenteral administration (IV/IM) is typically reserved for acute episodes and is usually not continued for more than two days, transitioning to an oral or rectal form if needed. Topical gels are typically applied four times daily to the affected area.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Diclostar

Evidence for Symptomatic Relief in Chronic Joint Conditions

Research for Diclostar (Diclofenac) in the context of chronic joint symptoms primarily involves Randomized Controlled Trials (RCTs) and systematic reviews. These studies have been essential in exploring how outcomes related to physical discomfort and daily functioning were measured in studies of Diclostar for conditions characterized by periods of heightened symptoms. The evidence describes the results of investigations into both the oral and topical forms of the medicine.

Research on Osteoarthritis Symptoms

The study profile for Diclostar was evaluated in research exploring its use in conditions marked by functional limitations, specifically symptomatic osteoarthritis (OA). Research focused on adult populations and the outcomes that reflect daily functioning or activity level. Outcomes studied included changes in pain intensity and measurements of functional mobility and stiffness.

Short-term and intermediate-term trials (up to 12 weeks) report how symptoms evolved in the observed populations. Findings describe patterns related to the temporary shift in perceived discomfort measurements during the study period. There is limited information for long-term outcomes regarding the durability of measured effects, and research does not explore whether Diclostar is studied for modifying the underlying structural progression of OA.

Research on Rheumatoid Arthritis Symptoms

Diclostar was evaluated in studies examining its potential role in rheumatoid arthritis (RA). Studies explored outcomes linked to inflammatory states, including measures of joint swelling and tenderness, alongside patient-reported pain scores. Findings indicate that the most consistent patterns were related to symptom measurements observed during the study periods. Research focused on the measurement of symptoms only; the evidence does not explore its role as a disease-modifying agent.


Evidence for Acute and Episodic Pain Management

The evidence base for acute pain is drawn from short-term, time-sensitive RCTs. Diclostar was studied for various acute pain scenarios, including short-term use after minor surgery or following acute injuries. Research examined time-sensitive outcomes like the time to measurement change and the magnitude of pain reduction measured over the immediate hours or days following the acute event.

Research was conducted during periods of increased symptom activity for episodic conditions like primary dysmenorrhea and acute migraine attacks. Findings describe patterns observed related to measured symptom relief during the acute episode. Research does not provide insight into chronic or preventive treatment regimens for either condition, and the findings reflect the specific conditions under which they were conducted.

Key Studies & References Osteoarthritis in over 16s: diagnosis and management (NICE guideline NG226)

Frequently Asked Questions (FAQ)

Common questions about Diclostar (FAQ)

Q: How long does it typically take for Diclostar to start working?

A: Official information indicates that oral tablets and capsules are described to start producing effects within approximately 20 to 30 minutes of administration. Other forms, such as rectal suppositories, may take a few hours before the effects are noticed.

Q: Can Diclostar cause weight gain or loss?

A: Weight change is not consistently listed as a common or frequently reported adverse effect in official regulatory documents. However, some documented side effects, such as swelling or fluid retention (edema), can sometimes be associated with a change in body weight.

Q: Can Diclostar affect sleep or cause insomnia?

A: Regulatory safety documents list central nervous system effects, including drowsiness, as a reported side effect. CNS effects are noted in regulatory documents, but insomnia is not consistently listed as a common reported side effect.

Q: Why is Diclostar sometimes prescribed for back pain?

A: Official approvals for Diclostar cover the management of pain, swelling, and inflammation in various musculoskeletal and joint disorders. Its use is consistent with its authorized purpose for conditions characterized by pain and inflammation in the joints and muscles.

Q: Can Diclostar be crushed or split if it's a tablet?

A: Regulatory instructions state that delayed-release, extended-release, and slow-release forms must be swallowed whole. Crushing, splitting, or chewing these specific types of tablets is not permitted as it can interfere with how the medication is released and absorbed.

Q: What happens if I miss a dose of Diclostar?

A: Official patient information addresses what to do regarding missed doses. These instructions typically specify that a dose is either taken when remembered or skipped, depending on how close it is to the next scheduled administration time.

Q: Does taking Diclostar impact my ability to drive or operate machinery?

A: Regulatory warnings indicate that Diclostar may impair a person's ability to drive or operate machinery. This is because documented side effects include dizziness, drowsiness, and potential visual disturbances.

Q: Are there any specific dietary restrictions while taking Diclostar?

A: Official regulatory guidance focuses on drug-drug and drug-alcohol interactions. There are typically no general specific dietary restrictions, beyond the instruction for certain oral solutions to be taken on an empty stomach to ensure proper absorption.

Q: How quickly does Diclostar leave the body after the last dose?

A: Pharmacokinetic data in regulatory documents indicate that the active ingredient has a relatively short elimination half-life. This means the time it takes for half of the drug to be cleared from the system averages approximately 1 to 2 hours.

Q: Is it normal to feel a little dizzy after taking Diclostar?

A: Official safety documents classify dizziness as a common side effect. This means it is among the more frequently reported adverse reactions experienced by people taking the medicine.

Q: Can Diclostar cause changes in mood or behavior?

A: Official regulatory documents list nervous system effects such as dizziness and headache. However, changes in mood or behavior are not consistently listed among the commonly reported adverse effects of the medication.

Q: Is it okay to take Diclostar with coffee or caffeine?

A: Regulatory drug interaction listings focus primarily on other medications and alcohol. There are typically no specific official warnings or contraindications regarding the concurrent consumption of coffee or caffeine in the core drug labeling.

Q: Does Diclostar work for headaches or migraines?

A: Official documents in some regulatory jurisdictions specifically approve Diclostar, particularly the potassium salt formulation, for the treatment of acute migraine attacks. This is one of its recognized uses for episodic pain management.

Q: Can young adults or teens use Diclostar?

A: For most systemic uses, official regulatory information states that the safety and effectiveness of Diclostar are typically not established for children and adolescents. Use in this population is generally limited or requires specific evaluation.

Q: What types of food should be avoided when taking Diclostar?

A: Regulatory guidance does not provide a general list of specific food types to avoid. Instructions mainly focus on the timing of administration for certain oral forms, where taking them with food may reduce the rate of absorption.

Q: Is there a liquid form of Diclostar?

A: Yes, various forms are approved by regulators. These include an oral powder solution which becomes a liquid when mixed, as well as topical solutions and gels.

Q: Is Diclostar the same as other anti-inflammatory drugs?

A: Diclostar contains the active ingredient Diclofenac, which is classified in official documents as a Nonsteroidal Anti-Inflammatory Drug (NSAID). This confirms that it belongs to the same pharmacological class as other medicines used to treat inflammation and pain.

Q: What is the difference between Diclostar and ibuprofen?

A: Both are classified as Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) by regulatory bodies. However, official safety texts indicate that diclofenac may share some of the cardiovascular risks seen with more selective anti-inflammatory drugs, a distinction that is sometimes applied when discussing different NSAIDs.

Q: Does Diclostar come in different strengths or formulations?

A: Yes, official regulatory documents describe multiple strengths (e.g., 50 mg, 75 mg, 100 mg) that are available. It is also manufactured in various approved formulations, including tablets, capsules, topical gel, and injection solution.

Q: Is Diclostar available over the counter in some countries?

A: The regulatory status of Diclostar varies globally. Some jurisdictions have reclassified certain oral tablets to prescription-only status due to safety concerns, while lower-strength topical forms often remain available for purchase without a prescription.

Q: How does Diclostar affect inflammation versus pain?

A: The official mechanism of action describes Diclostar's role in inhibiting the synthesis of prostaglandins. This single action is cited as the basis for both its anti-inflammatory effects and its analgesic (pain-relieving) effects.

Q: What is the main difference between delayed-release and immediate-release Diclostar?

A: Delayed-release forms are specifically coated to prevent the medication from dissolving until it passes through the stomach, which can protect the digestive lining. Immediate-release forms dissolve and are absorbed rapidly into the body for a quicker onset of action.

How should Diclostar be stored and disposed of?

How to Store and Dispose of Diclostar

The storage and disposal of Diclostar (diclofenac) must adhere to conditions specified in official regulatory labeling to maintain quality and safety.

Storage Requirements

Element Official Requirement
Temperature Store at Controlled Room Temperature, 20 C to 25 C (68 F to 77 F).
Protection Must be protected from excessive moisture, heat, and direct light; do not freeze.
Container Keep in the container it came in, with the container tightly closed.
Security Must be kept out of the reach and sight of children.

Disposal Instructions

Unused or expired Diclostar must be handled according to official guidance. Patients should ask a healthcare professional how to properly discard the medicine. Do not dispose of the product via wastewater or household trash if a local drug take-back program is available. Before discarding empty containers, scratch out all personal information on the label.

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

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