Usage
Diclofenac diethylamine is a topical non-steroidal anti-inflammatory drug (NSAID) primarily prescribed for the relief of pain and inflammation associated with musculoskeletal and joint disorders, such as osteoarthritis, sprains, strains, and bruises. It is also used to treat actinic keratosis, a skin condition that can potentially develop into skin cancer.
Alternate Names
Diclofenac diethylamine is also known as diclofenac diethylammonium or diclofenac diethylammonium salt. Brand names include Voltaren Emulgel, Pennsaid, and Solaraze.
How It Works
Pharmacodynamics: Diclofenac diethylamine works by inhibiting cyclooxygenase (COX)-1 and COX-2 enzymes. These enzymes are responsible for producing prostaglandins, which contribute to pain and inflammation. By inhibiting COX enzymes, diclofenac reduces the production of prostaglandins, thereby alleviating pain and inflammation at the application site.
Pharmacokinetics: When applied topically, diclofenac diethylamine is absorbed through the skin and reaches the underlying tissues. A small amount of the drug may enter the systemic circulation, but levels are generally much lower than with oral diclofenac. It is metabolized primarily in the liver and excreted by the kidneys.
Dosage
Standard Dosage
Adults:
A cherry- to walnut-sized amount (1-4 g of gel, equivalent to 20-80 mg of diclofenac sodium) should be applied to the affected area two to four times daily. The maximum daily dose is 8g (160 mg diclofenac sodium or 185.6 diclofenac diethylamine). This medicine is not for long-term use. For acute pain, treatment should not exceed one week without medical advice. Do not apply to broken skin. Wash hands after applying, unless the gel is applied to the hands. If using the topical solution for osteoarthritis of the knee, apply 40 drops (4g) four times daily to each affected knee.
Children:
Use in children younger than 14 years old is generally not recommended for topical application. The exact dose in children 14 years and older must be determined by a doctor.
Special Cases:
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Elderly Patients: Use the lowest effective dose and duration of treatment and monitor for side effects.
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Patients with Renal Impairment: Although topical application leads to minimal systemic absorption, caution is advised, and the lowest effective dose should be used.
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Patients with Hepatic Dysfunction: Similar to renal impairment, caution is advised due to the potential for liver metabolism.
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Patients with Comorbid Conditions: Monitor patients with cardiovascular disease, hypertension, or a history of gastrointestinal bleeding carefully.
Clinical Use Cases
Diclofenac diethylamine is primarily intended for topical use and is not typically administered for cases requiring intubation, surgical procedures, mechanical ventilation, or ICU use. In emergency situations requiring systemic effects, other formulations of diclofenac, like IV or oral, are usually preferred.
Dosage Adjustments
Dosage adjustments are generally not required for topical diclofenac diethylamine, but always use the lowest effective dose. In cases of severe renal or hepatic impairment, consult a specialist before use.
Side Effects
Common Side Effects
Itching, redness, burning or tingling sensation at the application site, skin rash.
Rare but Serious Side Effects
Allergic reactions (skin rash, hives, swelling, difficulty breathing), stomach pain, black or bloody stools, chest pain, shortness of breath, sudden vision changes, weakness on one side of the body.
Long-Term Effects
Long-term use of topical diclofenac diethylamine can increase the risk of kidney and liver problems, and possibly cardiovascular events.
Adverse Drug Reactions (ADR)
Severe allergic reactions, gastrointestinal bleeding, acute renal failure, Stevens-Johnson syndrome.
Contraindications
Hypersensitivity to diclofenac or any other NSAIDs. Third trimester of pregnancy. Perioperative period in the setting of coronary artery bypass graft (CABG) surgery.
Drug Interactions
Concurrent use of other topical medications on the same area should be avoided. Potential interactions with oral medications are minimal due to low systemic absorption, however, caution is advised with anticoagulants, other NSAIDs, and some diuretics. Alcohol and smoking may increase the risk of gastrointestinal bleeding.
Pregnancy and Breastfeeding
Diclofenac is contraindicated in the third trimester of pregnancy due to risk of premature closure of the ductus arteriosus and other fetal complications. Use in the first and second trimesters is generally not recommended unless potential benefits outweigh the risks. While a small amount of diclofenac may be excreted in breast milk, it is generally considered compatible with breastfeeding. Avoid applying the gel directly on the breasts.
Drug Profile Summary
- Mechanism of Action: Inhibits COX-1 and COX-2 enzymes, reducing prostaglandin synthesis and thereby pain and inflammation.
- Side Effects: Local skin reactions (itching, redness, burning). Rarely, systemic effects like gastrointestinal bleeding, allergic reactions.
- Contraindications: Hypersensitivity to diclofenac, third-trimester pregnancy.
- Drug Interactions: Minimal with topical application, but caution with oral anticoagulants and other NSAIDs.
- Pregnancy & Breastfeeding: Contraindicated in the third trimester. Generally compatible with breastfeeding.
- Dosage: Apply 1-4g to the affected area two to four times daily. Maximum daily dose is 8g. Not for long-term use.
- Monitoring Parameters: Assess for local skin reactions and, with prolonged use, monitor renal and liver function.
Popular Combinations
Topical diclofenac diethylamine is generally not used in combination with other topical products applied to the same area. It is sometimes used as part of a pain management plan which may include oral analgesics if needed.
Precautions
- Avoid application to broken skin, open wounds, or infected areas.
- Wash hands after use unless applying to the hands.
- Protect the treated area from sunlight.
- Patients with a history of gastrointestinal ulcers or bleeding should be monitored closely.
- Avoid alcohol while using topical diclofenac due to increased bleeding risk.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Diclofenac diethylamine?
A: Apply 1-4g to the affected area two to four times daily. Maximum daily dose is 8g.
Q2: Can I use Diclofenac diethylamine if I am pregnant or breastfeeding?
A: It is contraindicated in the third trimester of pregnancy. Generally considered compatible with breastfeeding but avoid applying on the breasts.
Q3: What are the common side effects of Diclofenac diethylamine?
A: Itching, redness, burning, or tingling sensation at the application site.
Q4: How does Diclofenac diethylamine work?
A: It inhibits COX enzymes and reduces prostaglandin production, thus relieving pain and inflammation.
Q5: Can I use Diclofenac diethylamine on broken skin?
A: No, avoid applying to broken skin or open wounds.
Q6: How long can I use topical diclofenac diethylamine?
A: Do not use for more than one week for acute pain unless directed by a doctor.
Q7: Are there any drug interactions I should be aware of with topical diclofenac?
A: Potential for drug interactions with topical application is low, but concurrent use of other topical medications on the same area should be avoided. Exercise caution when using oral anticoagulants, other NSAIDs, and some diuretics.
Q8: What should I do if I accidentally apply too much Diclofenac diethylamine?
A: While unlikely to be harmful, contact a physician or poison control center if you experience any unusual symptoms.
Q9: Can diclofenac diethylamine be used in children?
A: Topical diclofenac is generally not recommended for children under 14 years of age.
Q10: What should I do if my pain doesn’t improve after using Diclofenac diethylamine?
A: Consult your doctor if your symptoms do not improve or worsen after a few days.
