Diclofenac Diethylamine (VOLTAREN EMULGEL Extra Strength)

1. Health Canada Product Monograph — Diclofenac Diethylamine

• Diclofenac diethylamine gel is used for relief of pain from recent, localized muscle or joint injuries such as sprains, strains, or sports injuries, for example a sprained ankle or a strained shoulder or back muscle.
• It is intended as an adjunct to other measures, such as rest, for relieving discomfort from these injuries, rather than as a treatment for the underlying injury itself.
• Health Canada has not authorized an indication for use in patients under 18 or over 65 years of age, since no supporting data for these age groups were submitted for this product.

Contraindicated in pregnancy. Confirm pregnancy status and discuss alternative therapy with the prescriber before dispensing.

• No clinical experience with diclofenac diethylamine gel in pregnancy has been established, so it is not recommended for use during pregnancy.
• It is contraindicated during the last trimester of pregnancy because of the risk of reduced uterine contractions, impaired fetal kidney function with reduced amniotic fluid, and premature closure of the fetal ductus arteriosus.
• Animal studies have shown an increased incidence of difficult labour and delayed delivery when diclofenac administration continued into late pregnancy.
• If diclofenac diethylamine gel is used by a woman attempting to conceive, or during the first or second trimester, the dose should be kept as low and the treatment as short as possible, and a doctor should be consulted.

• It is not known whether topically applied diclofenac passes into human breast milk, although animal studies detected diclofenac in milk after oral dosing.
• Caution is warranted while breastfeeding, since many drugs are excreted in human milk.
• Diclofenac diethylamine gel should only be used during breastfeeding if the expected benefit justifies the potential risk to the infant.
• If used while breastfeeding, the gel should not be applied to the breast area, and should not be used at a higher amount or for longer than recommended.
• Nursing women should consult their doctor or pharmacist before using this product.

• Health Canada has not authorized an indication for use in patients over 65 years of age, since no supporting data for this age group were submitted.
• Older adults are generally at higher risk of the gastrointestinal, kidney, and cardiovascular effects associated with NSAIDs, so extra caution is reasonable even though absorption through the skin is low.

• Health Canada has not authorized an indication for use in patients under 18 years of age, since no supporting pediatric data were submitted.
• Keep this product out of the sight and reach of children; accidental application near a child's eyes has caused eye and nasal irritation, and accidental ingestion of even a small amount is not recommended.

• Apply the gel to the affected area twice daily, once in the morning and once in the evening, using the dosing card or dosing ring supplied with the product to measure each application; the total amount applied per day should not exceed the equivalent of 4 g across all treated areas.
• Applying more gel than recommended will not improve pain relief.
• Treatment should not continue for more than 7 days for muscle and joint injuries unless a doctor advises otherwise; if the condition has not improved, or has worsened, within 7 days, a doctor should be consulted to rule out another cause of the pain.
• The gel is for topical use only and must never be taken by mouth.
• After each application, wipe excess gel from the hands with a tissue (unless the hands are the area being treated), then wash them, and discard the tissue; wait until the gel has dried before showering or bathing.
• If an application is missed, apply it as soon as remembered, then resume the regular schedule; do not apply a double amount to make up for the missed application.
• No specific dose adjustment has been established for hepatic or renal impairment, since systemic absorption through the skin is low, but caution and a doctor's guidance are advised in these patients.

If overdose is suspected, seek emergency medical attention immediately or contact your regional Poison Control Centre without delay.

• Because very little of the topically applied gel is absorbed into the body, overdose is very unlikely with normal use.
• If a large enough amount of the gel is accidentally swallowed, effects similar to an overdose of oral diclofenac tablets can occur.
• Management follows general measures used for NSAID poisoning, with supportive and symptomatic treatment for problems such as low blood pressure, kidney failure, seizures, gastrointestinal irritation, or slowed breathing.
• Treatments such as forced diuresis, dialysis, or hemoperfusion are unlikely to help remove diclofenac from the body, since it binds extensively to blood proteins.

• Pain at the application site may occur.
• Itching (pruritus) at the application site may occur.
• Dermatitis, including contact dermatitis, at the application site may occur.
• Skin rash may occur.
• Redness (erythema) of the skin may occur.
• Eczema at the application site may occur.

Serious side effects require immediate discussion with the prescriber or emergency care.

• Blistering skin reactions (bullous dermatitis) have been reported rarely.
• Photosensitivity reactions, where treated skin reacts abnormally to sunlight, have been reported rarely.
• Hypersensitivity reactions, including hives (urticaria) and swelling of the face or throat (angioedema), have been reported rarely.
• Asthma, including difficulty breathing, has been reported rarely, particularly in patients with a history of bronchial asthma or aspirin/NSAID sensitivity.
• A pustular skin rash has been reported very rarely.
• Although absorption through the skin is low, this product's labelling notes that if enough diclofenac were absorbed, for example with extensive or prolonged use, the effects known to occur with oral diclofenac could theoretically occur, including gastrointestinal bleeding or ulceration.
• Liver problems, including hepatitis, liver failure, and jaundice (yellowing of the skin or eyes), are among the effects reported with oral diclofenac.
• Kidney problems, including acute kidney injury and nephrotic syndrome, are among the effects reported with oral diclofenac.
• Heart problems, including heart attack, heart failure, and abnormal heart rhythms, are among the effects reported with oral diclofenac.
• Blood disorders, including a marked drop in platelets, white blood cells, or red blood cells, are among the effects reported with oral diclofenac.
• Severe skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, are among the effects reported with oral diclofenac.
• Aseptic meningitis and stroke are among the rare effects reported with oral diclofenac.
• Seek urgent medical attention for signs of a severe allergic reaction, unexplained bruising or bleeding, yellowing of the skin or eyes, chest pain, or severe shortness of breath.

• Use with caution in patients taking medication for an active peptic ulcer, such as a proton pump inhibitor or an H2-receptor antagonist, since isolated cases of gastrointestinal bleeding have been reported with this gel.
• Use with caution in patients with a history of asthma or bronchial hyperreactivity, since NSAIDs, including topical diclofenac, can rarely precipitate bronchospasm.
• Warn patients against excessive sun exposure on treated skin, to reduce the risk of a photosensitivity reaction.
• Do not use with an airtight occlusive dressing; a non-occlusive bandage is acceptable.
• Apply only to intact, healthy skin; do not apply to open wounds, skin infections, active eczema, or broken skin.
• Keep the gel away from the eyes and mucous membranes, and never take it by mouth.
• Use with caution if applying to a relatively large area of skin or for an extended period, since this increases the chance of the drug being absorbed into the bloodstream.
• This product contains propylene glycol, which may cause mild local skin irritation in some patients.
• This product contains butylhydroxytoluene, which may cause local skin reactions such as contact dermatitis, or irritation of the eyes and mucous membranes.
• Patients should be cautious around open flames or while smoking, since the gel contains paraffin, which can build up on fabric such as clothing, bedding, or dressings and become flammable; washing affected fabric reduces but does not fully remove this buildup.

• Contraindicated in patients with known hypersensitivity to diclofenac diethylamine gel or to any ingredient in the formulation, including any component of the container.
• Contraindicated in patients with known hypersensitivity to diclofenac, acetylsalicylic acid, or other nonsteroidal anti-inflammatory drugs.
• Contraindicated in patients in whom asthma attacks, angioedema, hives, or acute rhinitis have been triggered by acetylsalicylic acid or other NSAIDs, with or without a history of chronic asthma.
• Contraindicated for concurrent use with other diclofenac-containing products.
• Contraindicated for concurrent use with oral NSAIDs.
• Contraindicated during the last trimester of pregnancy.
• Contraindicated following coronary artery bypass graft surgery.

• No formal drug-drug interaction studies have been conducted for this gel, since systemic absorption through the skin is expected to be very low, unlike oral NSAIDs.
• Oral anticoagulants, including warfarin, acenocoumarol, phenprocoumon, fluindione, and clopidogrel, have been associated in isolated marketplace reports with bleeding events or increased INR when used together with this gel; caution and monitoring are reasonable.
• Other oral or topical NSAIDs used concurrently, including ibuprofen, acetylsalicylic acid, naproxen, piroxicam, and celecoxib, may increase the risk of adverse effects such as pain, gastrointestinal bleeding, or kidney problems.
• Antihypertensive drugs, including ACE inhibitors and angiotensin receptor blockers, have been associated in isolated reports with increased blood pressure or reduced kidney function when combined with this gel.
• Isolated cases of lithium toxicity, and of confusion in patients on rivastigmine, have been reported with concurrent use of this gel.

• Food interactions do not apply to this product, since it is applied to the skin and is not taken by mouth.

• Apply twice daily, in the morning and in the evening; because this is a topical product, food timing does not apply.

• Store at room temperature, between 15°C and 30°C.

• Diclofenac diethylamine gel (VOLTAREN EMULGEL Extra Strength) is a topical NSAID for short-term relief of pain from recent sprains, strains, and similar muscle or joint injuries.
• Apply it only to intact skin, avoiding the eyes, mucous membranes, and open wounds, and wash your hands after each application.
• Do not use for more than 7 days without medical advice, and see a doctor if the pain does not improve or gets worse.
• This gel is contraindicated in the last trimester of pregnancy and after coronary artery bypass surgery.
• Seek urgent medical attention for signs of a severe allergic reaction, unusual bruising or bleeding, yellowing of the skin or eyes, or severe breathing difficulty.