Difnal uses, dosage, side effects and composition

Description and composition of Difnal tablets


Difnal is a pain killer. It belongs to a class of drug called nonsteroidal anti-inflammatory drugs otherwise known as NSAIDs.

Difnal contains diclofenac as its active ingredient. It also contains inactive ingredients called excipients in sufficient quantities. 

Since Difnal contains diclofenac as its active ingredient, we will be using either diclofenac or Difnal in this article. That’s to say that we will them interchangeably. Just note that they technically mean the same thing.


Diclofenac is often formulated as a sodium salt. It can also be formulated as a potassium especially for the hypertensive patients.

Difnal comes in different strengths and dosage forms. Commonly available strengths are 50 mg, 75 mg and 100 mg. The 100 mg is dosed once daily and are usually sustained release formulation.

Commonly available dosage forms of Difnal include tablets, injections, cream, gels, and oral solution.

Actions and pharmacology of Difnal tablets

Diclofenac Sodium and diclofenac potassium are non-steroidal anti-inflammatory drugs (NSAIDs) with analgesic and antipyretic properties.


They inhibits the activity of the enzyme cyclo-oxygenase, resulting in decreased formation of precursors of prostaglandins and thromboxanes from arachidonic acid.

Diclofenac SR is a slow release preparation designed to release Diclofenac over a period of time.

It is rapidly absorbed after oral administration.

Although orally- administered Diclofenac is almost completely absorbed, it is subject to first-pass metabolism so that only 50 to 60% of the drug reaches the systemic circulation in the unchanged form.

Diclofenac penetrates synovial fluid, readily crosses the placenta and is excreted in breast milk.

It is highly protein bound. The terminal plasma half-life is about 1 to 2 hours.

It is metabolised to 4-hydroxydiclofenac, 5-hydroxydiclofenac, 3′-hydroxydiclofenac and 4,5-dihydroxydiclofenac.

It is excreted in the form of glucuronide and sulphate conjugates, mainly in the urine but also in the bile.

Uses of Difnal tablets and injections

Difnal tablets and injections are used for relief of pain and inflammation in conditions such as rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, acute gout and following some surgical procedures.

Side effects of Difnal tablets and injections

  • Common side effects of Diclofenac include nausea, headaches, diarrhoea, epigastric pain, anorexia, dyspepsia, flatulence, abdominal cramps, vertigo and dizziness.
  • Skin rashes and eruptions have occasionally been reported and rarely urticaria.
  • Isolated effects on the central nervous system include drowsiness, tiredness, impaired hearing, insomnia, Irritability, anxiety etc.
  • Occasional effects on the kidney include acute renal insufficiency, urinary abnormalities (eg. haematuria. proteinuria), nephrotic syndrome, papillary necrosis and interstitial nephritis.
  • Effects on the liver include occasional reports of elevation of serum aminotransferase enzymes (ALT, AST) and rarely liver function disorders.
  • Leucopenia, haemolytic anaemia, thrombocytopenia, aplastic anaemia and agranulocytosis have rarely been reported.
  • Hypersensitivity reactions (anaphylactic/anaphylactoid systemic reactions, hypotension, bronchospasm) have rarely been reported.
  • Many of these cardiovascular effects may occur secondary to NSAID-induced renal function impairment:
    • angina pectoris, irregular heartbeat, congestive heart failure, increased blood pressure and nose bleeds.
  • Cases of hair loss, bullous eruptions, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis (Lyell’s syndrome) and photosensitivity reactions have been reported


  • Patients with a history of gastrointestinal ulceration, haematemesis or melaena should be carefully observed.
  • Care should be taken when treating patients with ulcerative colitis, Crohn’s disease, haematological abnormalities or bleeding diathesis.
  • Caution is recommended in elderly patients and those with renal or hepatic impairment.
  • Monitoring of renal function, hepatic function and blood counts should be performed on long-term NSAID patients, as a precautionary measure.
  • Diclofenac sodium may trigger an attack in patients with hepatic porphyria.
  • Pate Patients should not drive or operate machinery if they experience dizziness or other central nervous system disturbances.
  • Caution in patients who must restrict their sodium intake.
  • Diclofenac should be stopped if liver function tests show abnormalities which persist or worsen, or if liver disease develops or if other symptoms such as eosinophilia or rash occur
  • Severe cutaneous reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis (Lyell’s syndrome) have been reported with diclofenac sodium.
  • Patients treated with diclofenac sodium should be closely monitored for sign of hypersentivity reactions.
  • Discontinue diclofenac sodium immediately if rash occurs.

Risk of gastrointestinal ulceration, bleeding and perforation with Nsaid

Serious gastrointestinal (GI) toxicity such as bleeding, ulceration and perforation can occur at any time, with or without warning symptoms, in patients treated with NSAIDs therapy.

Although minor upper Gl problems (eg dyspepsia) are common, usually developing early in therapy, prescribers should remain alert for ulceration and bleeding in patients treated with NSAIDS even in the absence of previous Gl tract symptoms.

Studies to date have not identified any subset of patients not at risk of developing peptic ulceration and bleeding.

Patients with prior history of serious adverse events and other risk factors associated with peptic ulcer disease (e.g. alcoholism, smoking, corticosteroid therapy) are at increased risk.

Elderly or debilitated patients seem to tolerate ulceration or bleeding less than other individuals and account for most spontaneous reports for fatal Gl events.

Pregnancy and Lactation

The use of diclofenac sodium/potassium is not advisable in pregnancy and lactation.

Contraindications of Difnal tablets and injections

Difnal is contraindicated in patients known to be hypersensitive to diclofenac sodium and diclofenac potassium

It is also contraindicated in patients who when taking aspirin or other non-steroidal anti-inflammatory drugs suffer attacks of asthma, urticaria or acute rhinitis, .

Should not be used in patients with active or suspected peptic ulcer or gastrointestinal bleeding.

It is contraindicated in patients with bone marrow depression

Drug interactions with Difnal tablets and injections

Difnal may increase plasma concentrations of lithium,  digoxin and methotrexate.

Concomitant use of diclofenac sodium and other NSAIDs may increase the frequency of side effects.

Diclofenac may increase cyclosporin nephrotoxicity as a result of their effect on renal prostaglandins.

There is an increased risk of convulsions if quinolone antibiotics are given while Diclofenac is being taken, and caution is advised when considering their use 

Increased serum potassium levels may result when Diclofenac is given concomitantly with potassium-sparing diuretics. Serum potassium levels should therefore be monitored.

Care is required when giving anticoagulants with Diclofenac as it may reversibly inhibit platelet aggregation. 

Non-steroidal anti-inflammatory drugs (NSAIDs) may increase the hypoglycemic effect of antidiabetic agents: dosage adjustments of the diabetic agent may be necessary; glipizide and glyburide may not be affected as much as the other oral antidiabetic agents, however, caution with concurrent use is recommended.

Diclofenac has also been reported to decrease the effects of antidiabetic agents, leading to hyperglycemia.

Overdose and treatment of Difnal tablets and injections

Clinical features of Difnal overdosage

Gastrointestinal symptoms (e.g. abdominal pain, nausea, vomiting), central nervous system effects (eg. lethargy, drowsiness) and renal effects have been reported.

More serious effects such as gastrointestinal hemorrhage, acute renal failure, convulsions and coma have also been reported.

Treatment for Difnal overdosage

Gastric lavage and treatment with activated charcoal should be used as soon as possible after overdosage in order to prevent absorption of the drug.

Further treatment is supportive and symptomatic.

Dosage and administration of Difnal tablets and injections

Adults: Oral, one 100 mg tablet a day.

Tablets should be swallowed whole preferably with food.

Elderly: Care should be used when treating patients who are frail or have a low body weight as they will in general be more susceptible to adverse reactions.

The lowest effective dose should be used in these patients. The standard adult dose may be used for other elderly patients.

Children: Not suitable for use in children.

How to store Difnal safely

Storage: Store below 25 C. Protect from moisture.


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