Diclofenac and Dizziness
Yes, diclofenac can cause dizziness as a recognized adverse effect, though it occurs at similar rates to other NSAIDs and is typically mild and transient.
Evidence from Guidelines and Drug Labels
The FDA-approved drug label for diclofenac explicitly lists dizziness as a common adverse effect 1. Multiple cardiovascular guidelines document dizziness as one of the most frequently reported adverse symptoms with NSAIDs, including diclofenac 1.
Incidence and Clinical Significance
Dizziness occurs at comparable rates to placebo in controlled trials. Studies comparing diclofenac 50 mg to placebo found no significant difference in the proportion of patients experiencing dizziness 2.
The symptom is typically mild and transient, resolving without intervention in most cases 3.
Dizziness is less common than gastrointestinal side effects, which remain the most frequent adverse reactions to diclofenac 4, 5.
Mechanism and Contributing Factors
Dizziness with diclofenac may result from multiple mechanisms:
Blood pressure effects: Diclofenac can increase mean blood pressure by approximately 5 mm Hg, which may contribute to dizziness, particularly in patients with cardiovascular disease or hypertension 6.
Prostaglandin inhibition effects on renal function and vascular tone may indirectly cause dizziness through hemodynamic changes 6.
Central nervous system effects: While diclofenac causes fewer CNS reactions than indomethacin, some central effects can occur 4.
High-Risk Populations
Certain patient groups warrant closer monitoring:
Elderly patients (≥75 years) are at increased risk for dizziness and falls when taking NSAIDs, including diclofenac 1.
Patients on concurrent medications that affect blood pressure (ACE inhibitors, ARBs, calcium channel blockers, beta-blockers) may experience additive effects leading to dizziness 1.
Patients with cardiovascular disease or risk factors are more susceptible to hemodynamic changes that may manifest as dizziness 1, 6.
Clinical Management
When prescribing diclofenac:
Start with the lowest effective dose (typically 50 mg) for the shortest duration necessary to minimize all adverse effects, including dizziness 6.
Monitor blood pressure in patients with hypertension or cardiovascular risk factors, as blood pressure elevation may contribute to dizziness 1, 6.
Assess for orthostatic hypotension in elderly patients or those on multiple cardiovascular medications 1.
Consider alternative NSAIDs if dizziness is problematic. Naproxen has a more favorable cardiovascular safety profile and may be preferred in patients with cardiovascular risk factors 6.
Important Caveats
While dizziness is a recognized side effect, it should not be the primary concern when prescribing diclofenac. The more serious risks include:
Cardiovascular thrombotic events (54% increased risk of recurrent MI, 140% increased mortality risk compared to placebo) 6.
Gastrointestinal ulceration and bleeding, which are more common and potentially more serious than dizziness 1, 5.
Renal impairment and hypertension, particularly in vulnerable populations 1, 6.
If a patient reports significant or persistent dizziness on diclofenac, evaluate for these more serious complications rather than dismissing it as a benign side effect 1.