Diclofenac (Voltaren®) versus Meloxicam (Mobic®)

Based on "Essential Pain Pharmacology"
written by Howard S. Smith, MD; Marco Pappagallo, MD

Difference between Diclofenac and Meloxicam chart

Diclofenac	Meloxicam
• Cataflam® • Cambia ® • Voltaren® • Voltaren-XR® • Zipsor ®	• Mobic® • Vivlodex®
Drug class
Nonsteroidal anti-inflammatory drug with anti-inflammatory, analgesic, and antipyretic properties.
Phenylacetic acid derivative	Oxicam derivative, a member of the enolic acid group of NSAIDs
Dose formulations
• Tablets • Capsules • Topical gel • Transdermal patch • Ophthalmic solution • Powder for oral solution • Injection • Suppositories Oral dosage forms of diclofenac are formulated as either the sodium or potassium salt: • Diclofenac potassium is formulated to be released and absorbed in the stomach. • Diclofenac sodium (usually enteric-coated tablets) resists dissolution in low pH gastric environments, releasing instead in the duodenum.	• Oral tablets • Oral suspension
Legal status
• Non-controlled substance (no potential for addiction) • Prescription only
FDA-approved indications
• Mild to moderate pain • Rheumatoid arthritis • Osteoarthritis • Ankylosing spondylitis • Primary dysmenorrhea • Migraine attacks	• Osteoarthritis • Rheumatoid arthritis • Juvenile rheumatoid arthritis in patients 2 years of age and older
"Off-label" uses
• Multimodal analgesic regimen • Dental surgical procedures • Acute pain in children • Biliary colic	• Chronic low back pain • Frozen shoulder • Ankylosing spondylitis • Other rheumatological conditions
Mechanism of action
• Both drugs inhibit prostaglandin synthesis via non-selective inhibition of COX-1 and COX-2 resulting in reduced formation of prostaglandins, thromboxane, and prostacyclin.
• Diclofenac inhibits COX-2 enzyme with greater potency than it does COX-1. Diclofenac appears to inhibit the lipoxygenase pathways, reducing inflammation by decreasing production of leukotrienes. • Diclofenac also inhibits arachidonic acid release and stimulates its reuptake	• Meloxicam is more selective inhibitor of COX-2 than diclofenac.
Half-life
• 1-4 hours • Diclofenac accumulates in synovial fluid, which may explain why its duration of therapeutic effect is considerably longer than its half-life1	• 18 - 20 hours
Oral bioavailability
• 50-60%	• 89%
Metabolism, Elimination
• Diclofenac undergoes first-pass or presystemic metabolism. First pass metabolism causes bioavailability of 50% despite almost complete oral bioavailability. • The drug is extensively metabolized by the cytochrome P450 3A4 and 2C8. • About 65% of diclofenac dose is excreted in the urine and about 35% through bile in the feces as conjugates of unchanged diclofenac and its metabolites.	Hepatic metabolism via CYP2C9, almost completely metabolized to 4 pharmacologically inactive metabolites. Most of meloxicam is excreted in the form of metabolites in urine and feces.
Contraindications
• Hypersensitivity to diclofenac.	• Hypersensitivity to meloxicam.
• History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs. • Use during the peri-operative period in the setting of coronary artery bypass graft (CABG) surgery. • Third trimester of pregnancy.
Warnings & precautions
• Potential adverse effects on the cardiovascular system. • Risk of GI ulceration, bleeding, and perforation. • Renal toxicity.
Side effects
• Nausea • Constipation • Dyspepsia • Headache • Dizziness • Vomiting • Modest elevation of hepatic transaminases	• Diarrhea • Upper respiratory tract infections • Dyspepsia • Flu-like symptoms
• Meloxicam causes significantly less dyspepsia, nausea, diarrhea, vomiting, abdominal pain compared to diclofenac3.
Pregnancy category
• C (prior to 30 weeks gestation) • D (after 30 weeks gestation, may cause premature closure of the ductus arteriosus)

Meloxicam advantages over Diclofenac

Meloxicam is less nephrotoxic than diclofenac 2.
Favorable gastrointestinal tolerability.
Diclofenac is associated with a higher incidence of hepatotoxicity than other NSAIDs.

Diclofenac advantages over Meloxicam

Diclofenac produces significant opioid sparing effect, while meloxicam does not 1.

Diclofenac vs Meloxicam for Dental Pain

Dental pain is mainly inflammatory, and nonsteroidal anti-inflammatory drugs are the best analgesics for this type of pain.

Meloxicam, taken prior to removal of third molar, better reduces pain and improves limited mouth opening than diclofenac4.

Diclofenac vs Meloxicam for Osteoarthritis

Both medications are indicated for the treatment of osteoarthritis.

Meloxicam and diclofenac are generally equally effective in relieving the acute pain associated with osteoarthritis5. However, meloxicam is better tolerated.

Meloxicam may better relieve pain during movement in patients with osteoarthritis of the knee6. Also, patients on meloxicam therapy consume less acetaminophen (Tylenol) concomitantly7.

Diclofenac vs Meloxicam for Sciatica

Both meloxicam and diclofenac are similarly effective for acute sciatica pain8.

Diclofenac vs Meloxicam for Low Back Pain

Meloxicam I.V. provides significantly faster onset of analgesic action (30 minutes), compared with diclofenac I.M. (60 minutes)9. Meloxicam better alleviates pain during movement 30 minutes after injection than diclofenac. Also, meloxicam is better tolerated and more effectively improves the quality of life.

References

1. Anwari JS, Anjum S, Al-Khunain S.Placebo controlled comparison of the opioid sparing effect of meloxicam and diclofenac after abdominal hysterectomy.Saudi Med J. 2008 Mar;29(3):379-83.
2. Ng LE, Halliwell B, Wong KP. Nephrotoxic cell death by diclofenac and meloxicam. BiochemBiophys Res Commun. 2008 May 9;369(3):873-7.
3. Hawkey C, Kahan A, Steinbruck K, Alegre C, Baumelou E, Begaud B, Dequeker J, Isomaki H, Littlejohn G, Mau J, Papazoglou S. Gastrointestinal tolerability of meloxicam compared to diclofenac in osteoarthritis patients. International MELISSA Study Group. Meloxicam Large-scale International Study Safety Assessment. Br J Rheumatol. 1998 Sep;37(9):937-45.
4. Orozco-Solis M, Garcia-Avalos Y, Pichardo-Ramirez C, et al. Single dose of diclofenac or meloxicam for control of pain, facial swelling, and trismus in oral surgery. Med Oral Patol Oral Cir Bucal. 2016 Jan 1;21(1):e127-34. PubMed
5. Valat JP, Accardo S, Reginster JY, Wouters M, Hettich M, Lieu PL; International Meloxicam Lumbar Osteoarthritis Group. A comparison of the efficacy and tolerability of meloxicam and diclofenac in the treatment of patients with osteoarthritis of the lumbar spine. Inflamm Res. 2001 Mar;50Suppl 1:S30-4.
6. GoeiThe HS, Lund B, Distel MR, Bluhmki E. A double-blind, randomized trial to compare meloxicam 15 mg with diclofenac 100 mg in the treatment of osteoarthritis of the knee. Osteoarthritis Cartilage. 1997 Jul;5(4):283-8.
7. Hosie J, Distel M, Bluhmki E. Meloxicam in osteoarthritis: a 6-month, double-blind comparison with diclofenac sodium. Br J Rheumatol. 1996 Apr;35Suppl 1:39-43.
8. Dreiser RL, Le Parc JM, Velicitat P, Lleu PL. Oral meloxicam is effective in acute sciatica: two randomised, double-blind trials versus placebo or diclofenac. Inflamm Res. 2001 Mar;50Suppl 1:S17-23.
9. Colberg K, Hettich M, Sigmund R, Degner FL. The efficacy and tolerability of an 8-day administration of intravenous and oral meloxicam: a comparison with intramuscular and oral diclofenac in patients with acute lumbago. German Meloxicam Ampoule Study Group. Curr Med Res Opin. 1996;13(7):363-77.

Published: March 28, 2018
Last updated: March 28, 2018