What are the side effects of tranexamic acid (TXA)?

Side Effects of Tranexamic Acid (TXA)

Tranexamic acid is generally safe with a favorable side-effect profile, but clinicians must be vigilant for dose-dependent seizures (particularly at doses >2g/day), thromboembolic events in high-risk patients, and renal accumulation in patients with kidney dysfunction. 1

Major Safety Concerns

Seizures (Dose-Dependent Risk)

• Seizure risk increases significantly with higher doses, particularly exceeding 2g/day (RR 3.05) 2
• Most commonly reported during cardiovascular surgery with doses up to 10-fold higher than recommended 1
• Meta-regression analysis confirms dose-dependent relationship (p=0.011) 2
• Patients with pre-existing seizure disorders show increased postoperative seizure rates (10.4% vs 7.1%, OR 1.53) 3
• EEG monitoring should be considered for patients with seizure history or those showing myoclonic movements or twitching 1
• Discontinue TXA immediately if seizures occur 1

Thromboembolic Events

• No increased risk of venous thromboembolism (VTE) or pulmonary embolism (PE) in most patient populations (RR 1.04) 2
• However, modest increase in ischemic stroke/TIA in patients with prior thromboembolism (5.6% vs 3.9%, OR 1.44) 3
• Cardiac surgery meta-analysis showed lower rates of myocardial infarction with TXA use 4
• Large Cochrane review of >8,000 patients demonstrated no increased arterial or venous thrombotic events 4
• Contraindicated in patients with active intravascular clotting 1
• Avoid concomitant use with pro-thrombotic agents (Factor IX concentrates, hormonal contraceptives) 1

Renal Complications and Dosing

• TXA is 90% renally excreted within 24 hours, requiring dose adjustment in renal impairment 4
• Accumulation in renal failure correlates with increased neurotoxicity and ocular toxicity 4
• Recommended dose adjustments: 1
  • Serum creatinine 1.36-2.83 mg/dL: 10 mg/kg twice daily
  • Serum creatinine 2.83-5.66 mg/dL: 10 mg/kg once daily
  • Serum creatinine >5.66 mg/dL: 10 mg/kg every 48 hours or 5 mg/kg every 24 hours

Neurological Side Effects

Visual Disturbances

• Patients with pre-existing visual disturbances show increased postoperative visual complications (4.2% vs 3.3%, OR 1.29) 3
• Animal studies showed retinal degeneration at high doses (250-1600 mg/kg/day), though not observed in humans 1
• For treatment >3 months, consider ophthalmic monitoring including visual acuity and optical coherence tomography 1
• Discontinue if ophthalmological changes occur 1

Dizziness

• TXA may cause dizziness, worsened by concomitant use of other dizziness-inducing drugs 1
• Advise patients to avoid driving or operating machinery until effects are known 1

Gastrointestinal Side Effects

• Nausea, vomiting, and diarrhea may occur 1
• Symptoms often resolve with dose reduction 1
• Gastrointestinal symptoms are common in overdose scenarios 1

Cardiovascular Side Effects

• Hypotension can occur with rapid intravenous injection 1
• Cardiac arrhythmias reported with inadvertent intrathecal administration 1
• Administer IV bolus over 10 minutes minimum to avoid hypotension 4

Hypersensitivity Reactions

• Anaphylactic reactions have been reported, though rare 1
• Allergic dermatitis and rash may occur 1
• Contraindicated in patients with prior hypersensitivity to TXA 1
• Discontinue immediately if serious reaction occurs and do not restart 1

Route-Specific Complications

Intrathecal Administration (Contraindicated)

• TXA is for intravenous use ONLY 1
• Inadvertent intrathecal administration causes serious adverse reactions including seizures and cardiac arrhythmias 1
• Cerebral edema and cerebral infarction reported with subarachnoid hemorrhage 1
• Syringes must be clearly labeled with IV route 1

Local/Topical Administration

• Wound healing complications reported with locally administered TXA 5
• Limited data on safety of topical use in cirrhosis patients (no impact on dental extraction outcomes) 4

Special Populations

Pregnancy and Postpartum

• Safe and effective for postpartum hemorrhage when given within 3 hours of birth 4
• No benefit and potential harm if administered >3 hours after birth 4
• Should be avoided in women with known thromboembolic events during pregnancy 4

Cirrhosis Patients

• Routine use discouraged in cirrhosis patients undergoing invasive procedures 4
• Increased risk of complications in renal dysfunction common in cirrhosis 4

Critical Timing Considerations

• Maximum benefit when administered early (within 1 hour of injury in trauma reduces mortality by 32%) 4
• Benefit decreases 10% for every 15-minute delay 4
• No benefit after 3 hours in postpartum hemorrhage, with potential harm 4

Contraindications Summary

• Active intravascular clotting 1
• Subarachnoid hemorrhage 1
• History of hypersensitivity to TXA 1
• Disseminated intravascular coagulation 4