What are the side effects of Pregabalin (Lyrica)?

Pregabalin Side Effects: A Comprehensive Overview

Pregabalin (Lyrica) is associated with numerous side effects, with the most common being dizziness, somnolence, peripheral edema, weight gain, and blurred vision. These effects can significantly impact quality of life and may require dose adjustment or medication discontinuation in some patients 1.

Common Side Effects

Central Nervous System Effects

• Dizziness: Occurs in 26-38% of patients, dose-dependent 1, 2
• Somnolence/Drowsiness: Affects 16-28% of patients 1, 2
• Ataxia: Reported in 5-20% of patients 1
• Confusion: Occurs in 2-7% of patients 1
• Abnormal thinking/difficulty with concentration: Affects 2-9% of patients 1
• Incoordination: Occurs in 2-6% of patients 1
• Tremor: Reported in 1-11% of patients 1

Visual Disturbances

• Blurred vision: Affects 5-12% of patients 1, 2
• Diplopia (double vision): Occurs in 2-12% of patients 1
• Abnormal vision: Reported in 1-5% of patients 1

Gastrointestinal Effects

• Dry mouth: Affects 4-6% of patients 1
• Constipation: Occurs in 2-7% of patients 1
• Increased appetite: Reported in 1-6% of patients 1

Metabolic Effects

• Weight gain: Affects 4-16% of patients, dose-dependent 1, 3
• Peripheral edema: Occurs in 2-12% of patients 1, 4
• Edema: Reported in 2-4% of patients 1

Rare but Serious Side Effects

Cardiovascular Effects

• Heart failure: Case reports suggest possible exacerbation or new-onset heart failure, particularly in elderly patients or those with pre-existing cardiac conditions 5

Psychiatric Effects

• Visual hallucinations: Rare adverse reaction, particularly at higher doses 6
• Euphoria: Occurs in 2% of patients 1, 2
• Suicidal thoughts or behavior: Rare but serious concern with all antiepileptic drugs 1

Dose-Related Side Effects

Side effects of pregabalin demonstrate a clear dose-response relationship 2:

• At 150 mg/day: Minimal side effects but also minimal efficacy for most conditions 7
• At 300 mg/day: Moderate side effect profile with improved efficacy 7
• At 600 mg/day: Highest efficacy but also highest incidence of side effects 7

Special Populations

Elderly Patients

• Higher risk of dizziness, somnolence, confusion, and peripheral edema 1
• Require lower starting doses and more gradual titration 4

Patients with Renal Impairment

• Pregabalin is primarily eliminated unchanged in urine 4
• Dose adjustment required based on creatinine clearance 1:
  • CrCl ≥60 mL/min: 300-600 mg/day in divided doses
  • CrCl 30-59 mL/min: 150-300 mg/day in divided doses
  • CrCl 15-29 mL/min: 75-150 mg/day in single or divided doses
  • CrCl <15 mL/min: 25-75 mg/day in single daily dose

Precautions and Warnings

1. Abrupt Discontinuation: Do not stop pregabalin suddenly as this may cause headaches, nausea, diarrhea, increased sweating, anxiety, or seizures (in epilepsy patients) 1

2. Alcohol Interaction: Avoid alcohol while taking pregabalin as it can increase side effects such as dizziness and somnolence 1

3. Driving and Operating Machinery: Patients should not drive or operate dangerous machinery until they know how pregabalin affects them 1

4. Allergic Reactions: Stop taking pregabalin and seek immediate medical attention for signs of serious allergic reaction (swelling of face, mouth, lips, gums, tongue, throat, or neck; trouble breathing; rash, hives, or blisters) 1

5. Concomitant Use with Other CNS Depressants: Use caution when combining with other medications that cause sedation 1

6. Cardiovascular Risk: Monitor patients with pre-existing cardiovascular disease for signs of heart failure, particularly peripheral edema progressing to central edema 4, 5

Management of Side Effects

1. Start Low, Go Slow: Begin with lower doses (75 mg/day) and gradually increase to minimize side effects 8

2. Timing of Administration: Taking pregabalin with food may help reduce gastrointestinal side effects 1

3. Monitor for Edema: Regular monitoring for peripheral edema is essential, especially in patients with cardiovascular risk factors 4, 5

4. Consider Alternatives: For patients who cannot tolerate pregabalin, alternative medications for neuropathic pain include tricyclic antidepressants, SNRIs (duloxetine), or topical treatments 8

5. Dose Reduction: If side effects are problematic, reducing the dose may help maintain some efficacy while improving tolerability 7

Pregabalin remains an important medication for neuropathic pain, fibromyalgia, and epilepsy, but careful patient selection, appropriate dosing, and vigilant monitoring for side effects are essential to optimize outcomes and quality of life.