Benzydamine is 1-Benzyl-3-(3-dimethylaminopropoxy)-1H-indazole. Benzydamine hydrochloride is a white, odourless, crystalline powder with a bitter taste, soluble in water, ethanol, methanol and chloroform. It is sparingly soluble in ether and petroleum ether.
Pharmacology: Benzydamine is an anti-inflammatory analgesic agent structurally unrelated to the steroid group. Benzydamine differs chemically from other non-steroidal anti-inflammatory agents in that it is a base rather than an acid. Animal models show that when administered systemically, benzydamine is effective against pain and oedema due to inflammatory conditions. It also inhibits granuloma formation. At concentrations used for topical treatment, benzydamine possesses local anaesthetic action. Benzydamine does not cause erosion of the gastric mucosa when given orally to rats at doses of up to 100 mg/kg. The analgesic activity of benzydamine was more pronounced in models involving an experimental inflammation rather than in non-inflammatory pain. In common with the aspirin-like drugs, benzydamine possesses an antipyretic activity. Peripheral reflexes were transiently inhibited after intravenous administration to cats.
Pharmacodynamics: The mechanism of anti-inflammatory action is not related to stimulation of the pituitary adrenal axis. Like other non-steroidal anti-inflammatory agents, benzydamine inhibits the biosynthesis of prostaglandins under certain conditions, but its properties in this respect have not been fully elucidated. The stabilising effect on cellular membranes may also be involved in the mechanism of action.
Pharmacokinetics: Benzydamine is well absorbed following oral administration. Following topical administration of benzydamine hydrochloride in solution form, benzydamine is well absorbed into the inflamed oral mucosa where it exerts anti-inflammatory and local anaesthetic actions. Plasma benzydamine levels following use of benzydamine orally are low and parallel the amount actually ingested. Benzydamine and its metabolites are excreted largely in the urine. Metabolism is largely by oxidative pathways, although dealkylation can be shown. Benzydamine has been detected in blood and urine following gargling with Difflam solutions. Most of the absorbed dose was eliminated in the first 24 hours. Repeated administration for 7 days did not result in accumulation of benzydamine in plasma.
Difflam solution is indicated for the relief of the painful conditions of the oral cavity including tonsillitis, sore throat, radiation mucositis, aphthous ulcers, post-orosurgical and periodontal procedures.
Dosage in adults: When used as a gargle, the usual dose of Difflam is 15 mL (approximately one tablespoon) which should be gargled for at least 30 seconds at 1½ to 3 hours throughout the day.
Dosage in children: 5-15 mL as gargle if able to do so, or as an oral rinse.
There are no known cases of overdosage with benzydamine hydrochloride solution. Difflam solution is unlikely to cause adverse systemic effects, even if accidental ingestion should occur. There is no specific antidote for benzydamine and should excessive quantities be ingested, the treatment should be symptomatic.
Difflam solution is contraindicated in patients with known hypersensitivity to drug or to any of the components of the vehicle.
Difflam solution is indicated for use as a rinse or gargle. It should not be swallowed but rather should be expectorated after each use. The product should generally be used undiluted but if burning or stinging occur, it may be diluted with water. If a sore throat is either caused or complicated by a bacterial infection, appropriate antibacterial therapy should be considered in addition to the use of Difflam solution.
Use in Pregnancy: The safety of benzydamine hydrochloride has not been established in pregnant patients. Risk to benefit ratio should be established if Difflam solution is to be used in these patients.
Use in Children: Difflam solution is not recommended in children under 6 years of age.
Pregnancy: The safety of benzydamine hydrochloride has not been established in pregnant patients. Risk to benefit ratio should be established if Difflam solution is to be used in these patients.
Lactation: Not applicable.
Difflam solution in topical oral preparations is generally well tolerated and side-effects are minor. The most commonly reported reaction is oral numbness. Occasional burning or stinging sensation may occur and has been reported in 1.4% of treated cases. Other local adverse effects were less common and included dryness or thirst, tingling, warm feeling in mouth and altered sense of taste.
There are no known drug interactions with benzydamine.
Protect from light. Store below 30°C.
A01AD02 - benzydamine ; Belongs to the class of other agents for local oral treatment.
Soln 0.15% w/v (clear and green) x 100 mL, 200 mL.